WO2011118934A2

WO2011118934A2 - Light emitting diode device and lighting device using the same

Info

Publication number: WO2011118934A2
Application number: PCT/KR2011/001827
Authority: WO
Inventors: Kang Kim
Original assignee: Kang Kim
Priority date: 2010-03-23
Filing date: 2011-03-16
Publication date: 2011-09-29
Also published as: TW201203636A; WO2011118934A3

Abstract

A light emitting diode (LED) device and a lighting device using the same are provided. An LED device includes a package body including an LED installed therein, a first electrode connected to an anode of the LED, a second electrode connected to a cathode of the LED, a first wiring connected to the first electrode, a second wiring connected to the second electrode, a bottom heat transfer metal layer formed on the bottom of the package body, and a metal plate bonded to the bottom heat transfer metal layer.

Description

LIGHT EMITTING DIODE DEVICE AND LIGHTING DEVICE USING THE SAME

The present invention relates to a light emitting diode device having a heat dissipation structure (or a heat sinking structure) and a lighting device using the same.

This application claims the benefit of Korea Patent Application No. 10-2010-0025801 filed on March 23, 2010, Korea Patent Application No. 10-2010-0067011 filed on July, 12, 2010, Korea Patent Application No. 10-2010-0067013 filed on July, 12, 2010, and Korea Patent Application No. 10-2011-0016927 filed on February 25, 2011, the entire contents of which is incorporated herein by reference for all purposes as if fully set forth herein.

A light emitting diode (LED) is a two-terminal diode element including compound semiconductor materials such as GaAs, AlGaAs, GaN, InGaN, AlGaInP, or the like. The LED emits visible light with light energy generated according to recombination of electrons and holes when power is applied to a cathode terminal and an anode terminal.

A white LED emitting white light may be implemented through three-color combination of a red LED, a green LED, and a blue LED or by combining yellow phosphor to a blue LED. The advent of the white LED has extended the application fields of LEDs from the indicators of electronic products to daily products, advertisement panels, or the like, and currently, as LED chips have high efficiency, they are used to replace the general illumination light sources such as streetlights, vehicle head lamps, fluorescent lamps, or the like.

In order to replace general illumination of tens to hundreds watts, a technique of increasing an output of an individual LED element has been developed. A high output LED element is required to have a design for releasing or dissipating heat generated from an LED chip. Research for improving an output of an individual LED element is ongoing in order to reduce the number of LED elements of an LED backlight unit for an LCD TV. When the output of an LED element is improved, the temperature of the LED chip negatively affecting the efficiency and life span of the LED element is bound to increase. Unlike other light sources such as a fluorescent lamp, an incandescent electric lamp (or a glow lamp), or the like, the LED converts approximately 70% or 80 % of input power into thermal energy, so a technique for effectively releasing the thermal energy is critical. In particular, an increase in the temperature of the LED chip due to heat is directly related to a degradation of luminous efficiency in the short term and reduces a life span of the chip in the long term, so lowering of 10℃ of the temperature of the LED chip can double the life span of the LED chip.

A heat transmission in the LED package is largely dependent upon a thermal conduction phenomenon. In order to smoothly perform heat conduction, thermal conductivity of each material must be high and thermal resistance on a contact surface between respective materials should be low for an effective heat release. The thermal resistance is defined as a value obtained by dividing a temperature difference between a temperature increased by heat generated according to power applied from an external source and an initial temperature, by the applied power. High heat resistance may mean that a temperature difference between the LED chip and an ambient temperature is great and heat generated from the LED chip is not properly released. Thus, the development of the technique of the high output LED package is focused on lowering thermal resistance by designing a package structure using a material having high thermal conductivity and being effective for heat releasing. Also, it is focused on lowering thermal resistance by optimizing a packaging process of mounting the LED chip.

In order to release heat of LED packages, a method of soldering the LED packages on a high-priced metal printed circuit board (PC) or a thermal clad board is commonly used. In this case, heat generated from the LED packages is released through the metal PCB.

The metal PCB has a structure in which a resin layer, a copper foil layer, a solder resist layer are stacked on an aluminum substrate. Heat generated from the LED chip is released along a heat transmission path by way of a package body of the LED package, and the solder layer, the copper foil layer, the resin layer, and the aluminum substrate of the metal PCB, and in this case, the resin layer has low thermal conduction, causing a bottle neck phenomenon of heat release in the thermal conduction flow.

When the LED packages are mounted in an array form on the metal PCB, the heat releasing effect only with the metal PCB has a low heat releasing effect, so a heat sink may be mounted on a lower surface of the metal PCB to release heat, and in this case, thermal grease, or the like, may be applied between the metal PCB and the heat sink in order to remove an air layer between the metal PCB and the heat sink. In this case, however, the thermal grease has thermal conductivity as low as about 2 to 3 W/mK, hindering a heat flow.

It is, therefore, an object of the present invention to provide an LED device capable of implementing a heat releasing structure for enhancing LED efficiency and lengthening a life span at a low cost, and a lighting device using the same.

In an aspect of the present invention, an LED device includes: a package body including an LED installed therein; a first electrode connected to an anode of the LED; a second electrode connected to a cathode of the LED; a first wiring connected to the first electrode; a second wiring connected to the second electrode; a bottom heat transfer metal layer formed on the bottom of the package body; and a metal plate bonded to the bottom heat transfer metal layer.

In another aspect of the present invention, an LED device includes: a package body including an LED installed therein; a first electrode connected to an anode of the LED; a second electrode connected to a cathode of the LED; a first wiring connected to the first electrode; a second wiring connected to the second electrode; a metal filler filled through a via hole penetrating the package body; and a metal plate bonded to the metal filler.

The bottom heat transfer metal layer may be bonded to the metal plate through any one of soldering, Ag epoxy, nano-size metal paste, and eutectic bonding.

The first and second electrodes may be spaced apart from an upper surface of the metal plate.

The metal plate may include only metal without a resin layer.

In an aspect of the present invention, a lighting device includes: metal plates to which one or more the LED packages bonded, respectively, the metal plates not having a resin layer; and a power generator for driving the LED packages.

the metal plates are radially disposed centering around the power generator in order to form a natural convection current passage of heat generated from the power generator.

In another aspect of the present invention, a lighting device includes: metal plates to which one or more LED packages bonded, respectively, the metal plates not having a resin layer; a concentration block having a sloped face for concentrating light from the LED packages; a power generator for driving the LED packages; and external wirings for electrically connecting the power generator and the LED packages.

In the present invention, the LED packages are bonded to the low-priced metal plates without a resin layer. As a result, the bottleneck phenomenon of the heat flow due to the resin layer formed in the existing metal PCB can be prevented, so the heat releasing effect can be maximized, and since the low-priced metal plates, instead of the high-priced metal PCB, are used, the economical efficiency can be improved. The LED device of the present invention can be applicable as any lighting device described in the background art.

In the present invention, the metal plates are radially disposed centering around the power generator to induce the natural convection current of heat generated from the power generator. As a result, the luminous efficiency and life span of the LED packages in the LED lighting devices can be improved and lengthened, thus enhancing reliability of the power generator.

In the present invention, the LED packages bonded to the metal plate are fabricated into a module structure which can be easily replaced, and the module is assembled along with the concentration block to enhance the concentration effect of the LED lighting devices and easily replace the LED package which has reached the end of its life span.

FIG. 1 is a sectional view of an LED device according to a first embodiment of the present invention;

FIG. 2 is a sectional view of an LED device according to a second embodiment of the present invention;

FIG. 3 is a sectional view of an LED device according to a third embodiment of the present invention;

FIG. 4 is a view illustrating an example of a serial or parallel circuit configuration of the LED devices illustrated in FIGS. 1, 2, and 3;

FIG. 5 is an equivalent circuit diagram illustrating an example of an LED and a Zener diode of an LED device according to a fourth embodiment of the present invention;

FIG. 6 is a sectional view illustrating an example in which electrodes of an LED package are short-circuited when the LED package is bonded to a metal plate in the LED device according to the fourth embodiment of the present invention;

FIG. 7 is a sectional view showing an example in which the electrodes of the LED package are lifted in order to prevent such short-circuit as in FIG. 6;

FIG. 8 is a sectional view illustrating an example in which external wirings are connected to the LED package in FIG. 7;

FIG. 9 is a sectional view showing an example in which bonded portions of the electrodes and wirings of the LED package of FIG. 8 are coated with an insulating tape or an insulating tube;

FIG. 10 is a sectional view illustrating an example in which an insulating pad or an insulating sheet is attached to a metal plate on which the LED of FIG. 8 is bonded;

FIG. 11 is an equivalent circuit diagram illustrating the cause of an LED short circuit defect generated when the LED packages of FIG. 7 are attached together to a single metal plate;

FIG. 12 is a sectional view illustrating an example in which the LED packages of FIG. 7 are bonded to separated metal plates in a one-to-one manner and the LED packages are connected in series;

FIG. 13 is an equivalent circuit diagram of the LED packages connected in series in FIG. 12;

FIG. 14 is a sectional view illustrating an example in which a plurality of LED packages are connected in series on a single metal plate;

FIG. 15 is a sectional view illustrating an LED device according to a fifth embodiment of the present invention;

FIG. 16 is a sectional view illustrating an example in which the LED package of FIG. 15 is bonded to a metal plate and wirings are connected to the LED package;

FIG. 17 is a sectional view illustrating an LED device according to a sixth embodiment of the present invention;

FIG. 18 is a plan view illustrating an example of an insulating material pattern and a solder material pattern printed on the metal plate illustrated in FIG. 16;

FIG. 19 is a plan view illustrating another example of an insulating material pattern and a solder material pattern printed on the metal plate illustrated in FIG. 16;

FIG. 20 is a sectional view illustrating an LED device according to a seventh embodiment of the present invention;

FIG. 21 is a sectional view illustrating an LED device according to an eighth embodiment of the present invention;

FIG. 22 is a sectional view of an LED lighting device according to a first embodiment of the present invention;

FIGS. 23 and 24 are sectional views illustrating a layout of a power generator and metal plates taken along line I-I in FIG. 22;

FIG. 25 is a sectional view of an LED lighting device according to a second embodiment of the present invention;

FIGS. 26 and 27 are vertical sectional views illustrating other examples of a reflector illustrated in FIG. 25;

FIG. 28 is an exploded perspective view of the LED lighting device according to the second embodiment of the present invention;

FIG. 29 is a sectional view of the LED lighting device of FIG. 28 in which an LED package, a metal plate, a concentration block are assembled;

FIG. 30 is a sectional view illustrating an example in which the LED packages of FIGS. 28 and 29 are connected by external wirings through pins and connectors;

FIG. 31 is a plan view illustrating an example in which the LED packages of FIGS. 28 and 29 are disposed in a matrix form and connected to a power generator;

FIG. 32 is a sectional view of an LED lighting device according to a third embodiment of the present invention;

FIG. 33 is a plan view illustrating an example of wiring connections of the LED packages of FIG. 32;

FIG. 34 is a plan view illustrating another example of wiring connections of the LED packages of FIG. 32; and

FIG. 35 is a sectional view showing a power generator (or an inverter), a housing and a rear cover of the LED lighting devices according to the second and third embodiments of the present invention.

In an LED device according to an embodiment of the present invention, soldering available metal is coated on a portion or the entirety of the bottom of a package body of an LED package and the bottom of the LED package is directly soldered to a low-priced metal plate without a resin layer to release heat generated from the LED chip through the soldered layer and the metal plate, thus increasing heat releasing efficiency. Here, the low-priced metal plate (or heat sink) includes a metal plate without a resin layer or a low-priced metal having a heat sink structure without a resin layer.

A copper plate, copper alloy pate, or an aluminum plate having a surface metal plated to allow for soldering may be used as the metal plate. In order to solder the metal coated on the bottom of the LED package and the metal plate, the solder material may contain 96.5% of tin (Sn), 3% of silver (Ag), and 0.5% of copper (Cu).

In the present invention, the LED package may be bonded to the low-priced metal plate without a resin layer by using an adhesive (or a bonder, or the like) or soldering method such as Ag epoxy having a thermal conductivity of about 3W/mK, an eutectic bonding method, nano-size metal paste soldering method or the like.

Since the bottom of the LED package is soldered to the metal plate or bonded to the metal plate through a thin resin layer, an anode electrode and a cathode electrode are formed on an upper portion of the LED package or bent to an upper side of the metal plate in order to prevent short circuit of the electrodes of the LED package through the metal plate. The metal plate may be used as a ground, and in this case, the bottom metal layer of the LED package may be connected to the anode electrode or the cathode electrode.

The LED package soldered to the metal plate may be provided with power from an external power source through an external wiring or provided with power from an external power source through an FR4 (Flame Retardant composition 4) PCB having a circuit pattern and an external wiring connected thereto.

The LED package may be implemented as an LTCC (Low Temperature Co-fired Ceramic)-based LED package, or an HTCC (High Temperature Co-fired Ceramic)-based LED package. Here, the package body employed in the HTCC-based LED package uses a high ceramic such as alumina (Al2O3) as a main ingredient and does not include low melting point glass, so it is fired at temperature of approximately 1500℃ or higher and has a high thermal conductivity compared with the LTCC package body. In the package body employed in the LTCC-based LED package, low melting point glass is contained in an electromagnetic functional ceramic, so its firing temperature can be lowered to about 1000℃ or lower.

Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, like reference numerals denote the like components. In describing the present invention, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the gist of the present invention, such explanation has been omitted but would be understood by those skilled in the art.

The names of elements used in the description hereinafter may be selected in consideration of easiness of description of a specification and may be different from the names of the components of the actual product.

With reference to FIG. 1, an LED package 100 according to a first embodiment of the present invention includes a package body 20, an LED chip 11,

internal wirings

12 and 13, a first electrode 15, a second electrode 16, a resin layer 14, a top heat transfer metal layer 17, a bottom heat transfer metal layer 19, and a metal filler 18.

The package body 20 may be made of a resin or an LTCC or HTCC-based ceramic material. A recess is formed on an upper surface of the package body 20. The top heat transfer metal layer 17 is formed on the bottom of the recess, and the LED chip 11 is soldered on the top heat transfer metal layer 17. The LED chip 11 is bonded on the top heat transfer metal layer 17 through any one of Ag apoxy, Flip chip bonding method, Eutectic bonding method and nano-size metal paste soldering method.

The top heat transfer metal layer 17 is formed between the first electrode 15 and the second electrode 16, and spaced apart from the

electrodes

15 and 16. An inner side wall of the package body 20 defining the recess includes sloped faces to enhance light reflection efficiency.

The first and

second electrodes

15 and 16 are formed on the sloped faces, namely, on the upper portions of the package body 20. The first electrode 15 may be connected to an anode of the LED chip 11 through an internal wiring 12. The second electrode 16 may be connected to a cathode of the LED chip 11 through an internal wiring 13. The

electrodes

15 and 16 are spaced apart from an upper surface of the metal plate 60, respectively.

The resin layer 14 is buried in the recess at the upper side of the package body 20 to cover the LED chip 11, the top heat transfer metal layer 17, the

internal wirings

12 and 13, or the like, to protect the elements from a physical impact or an infiltration of oxygen or moisture. The resin layer 14 may have a curved surface so as to serve as a lens.

One or more via holes penetrating the recess on the upper surface and the lower surface are formed and filled with a metal filler 18. The metal filler 18 may include one of metals among nickel (Ni), silver (Ag), tungsten (W), and molybdenum (Mo). The metal filler 18 connects the top heat transfer metal layer 17 and the bottom heat transfer metal layer 19.

The top heat transfer metal layer 17 and the bottom heat transfer metal layer 19 may has a structure in which any one of metal layers among nickel (Ni), copper (Cu), silver (Ag), tin (Sn), gold (Au) is plated on any one of copper (Cu), silver (Ag), tungsten (W) and molybdenum (Mo), respectively. The bottom heat transfer metal layer 19 may include a nickel layer-formed aluminum. One or more of gold (Au), silver (Ag), and copper (Cu) may be stacked on the nickel layer. The top heat transfer metal layer 17 may be connected to a ground terminal of the LED chip 11.

The bottom heat transfer metal layer 19 may be bonded to a low-priced metal plate 60 without a resin layer through any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding. When particles of metal powder are reduced into a nano- size, like nano-size metal paste, the particles can be sintered even at a low temperature, allowing for its use at a low temperature, and the thermal conductivity can be improved by the fine metal particle structure of the nano-particles.

Heat generated from the LED chip 11 is released along a heat releasing path including the LED chip 11, the top heat transfer metal layer 17, the metal filler 18, and the bottom heat transfer metal layer 19.

The LED package 100 is provided with driving power from an external power source through

external wirings

53 and 54 connected to the

electrodes

15 and 16 at the upper ends of the package body 20. Also, when a plurality of LED packages 100 are connected in series or in parallel, the neighboring LED packages 100 are connected through the

external wirings

53 and 54 connected to the

electrodes

15 and 16 at the upper ends of the package body 20. If the

external wirings

53 and 54 are connected to the

electrodes

15 and 16 through lower ends of the package body 20, they would be possibly brought into contact with the metal plate 60 to short-circuit the cathode and the anode of the LED chip 11.

FIG. 2 is a sectional view of an LED device according to a second embodiment of the present invention.

With reference to FIG. 2, the LED package 100 according to the second embodiment of the present invention includes a package body 28, an LED chip 21,

internal wirings

32 and 33, a first electrode 25, a second electrode 26, a resin layer 24, and a bottom heat transfer metal layer 27.

The package body 28 may be made of a resin or an LTCC or HTCC-based ceramic material. A recess is formed on an upper surface of the package body 28. A first electrode 25 and a second electrode 26 are formed on the bottom of the recess, and an LED chip 21 is formed on the second electrode 26. An inner side wall of the package body 20 defining the recess includes sloped faces to enhance light reflection efficiency. The first electrode 25 and the second electrode 26 are elongated to the sloped faces and upper faces of the package body 28. The first electrode 25 may be connected to an anode of the LED chip 21 through an internal wiring 22. The second electrode 26 may be connected to a cathode of the LED chip 21 through an internal wiring 13. The second electrode 26 extends to a portion under the LED chip 21. The resin layer 24 is buried in the recess at the upper side of the package body 28 to cover the LED chip 21, the

internal wirings

22 and 23, or the like, to protect the elements from a physical impact or an infiltration of oxygen or moisture.

Unlike the embodiment of FIG. 1, in the embodiment of FIG. 2, a top heat transfer metal layer is not formed on the upper portion of the package body 28 and a via hole penetrating the package body 28 is not formed.

The bottom heat transfer metal layer 27 may selectively have a structure in which any one of metal layers among nickel (Ni), copper (Cu), silver (Ag), tin (Sn) and gold (Au) is plated on any one of copper (Cu), silver (Ag), tungsten (W) and molybdenum (Mo). The bottom heat transfer metal layer 27 may include a nickel layer-formed aluminum. One or more of gold (Au), silver (Ag), and copper (Cu) may be stacked on the nickel layer. The bottom heat transfer metal layer 27 may be bonded to a low-priced metal plate 60 without a resin layer through any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding. The metal plate 60 may be connected to a ground power source.

external wirings

53 and 54 connected to the

electrodes

25 and 26 at the upper ends of the package body 28. Also, when a plurality of LED packages 100 are connected in series or in parallel, the neighboring LED packages 100 are connected through the

external wirings

53 and 54 connected to the

electrodes

25 and 26 at the upper ends of the package body 28.

Heat generated from the LED chip 21 is released along a heat releasing path including the LED chip 21, the cathode electrode 26, the package body 28, and the bottom heat transfer metal layer 27. The bottom heat transfer metal layer 27 is formed on the lower surface of the package body 28 to thereby increase the heat releasing efficiency of the LED package 100.

FIG. 3 is a sectional view of an LED device according to a third embodiment of the present invention.

With reference to FIG. 3, the LED package 100 includes a package body 38, an LED chip 31,

internal wirings

32 and 33, a first electrode 35, a second electrode 36, a resin layer 34, a top heat transfer metal layer 40, a bottom heat transfer metal layer 37, and a metal filler 39.

The package body 38 may be made of a resin, or an LTCC or HTCC-based ceramic material. A recess is formed on an upper surface of the package body 20. The first electrode 35, the second electrode 36, and the top heat transfer metal layer 40 are formed on the bottom of the recess. The LED chip 31 is formed on the top heat transfer metal layer 40. The top heat transfer metal layer 40 is formed between the first electrode 35 and the second electrode 36, and spaced apart from the

electrodes

35 and 36. An inner side wall of the package body 38 defining the recess includes sloped faces to enhance light reflection efficiency.

The first and

second electrodes

35 and 36 are elongated to the sloped faces and the upper faces of the package body 38. The first electrode 35 may be connected to an anode of the LED chip 31 through an internal wiring 32. The second electrode 36 may be connected to a cathode of the LED chip 31 through an internal wiring 33. The

electrodes

35 and 36 are spaced apart from an upper surface of the metal plate 60.

The resin layer 34 is buried in the recess at the upper side of the package body 38 to cover the LED chip 31, the

internal wirings

32 and 33, or the like, to protect the elements from a physical impact or an infiltration of oxygen or moisture.

A single via hole penetrating the recess on the upper surface and the lower surface is formed in the package body 28 and filled with a metal filler 39. Metal of the single metal filler 39 may include one of metals among copper (Cu), nickel (Ni), silver (Ag), tungsten (W), and molybdenum (Mo). The single metal filler 39 connects the top heat transfer metal layer 40 and the bottom heat transfer metal layer 37. The top heat transfer metal layer 40 and the bottom heat transfer metal layer 37 may each selectively have a structure in which any one of metal layers among nickel (Ni), copper (Cu), silver (Ag), tin (Sn) and gold(Au) is plated on any one of copper (Cu), silver (Ag), tungsten (W) and molybdenum (Mo). The bottom heat transfer metal layer 37 may include a nickel layer-formed aluminum. One or more of gold (Au), silver (Ag), and copper (Cu) may be stacked on the nickel layer. The bottom heat transfer metal layer 37 may be bonded to the low-priced metal plate 60 without a resin layer through any one of soldering, Ag apoxy and nano-size metal paste. The metal plate 60 may be connected to a ground power source.

external wirings

53 and 54 connected to the

electrodes

35 and 36 at the upper ends of the package body 38. Also, when a plurality of LED packages 100 are connected in series or in parallel, the neighboring LED packages 100 are connected through the

external wirings

53 and 54 connected to the

electrodes

35 and 36 at the upper ends of the package body 38.

Heat generated from the LED chip 31 is released along a heat releasing path including the LED chip 31, the top heat transfer metal layer 40, the single metal filler 39, and the bottom heat transfer metal layer 37.

The metal plate 60 may be made of any one copper plate, copper alloy pate, aluminum plated with any metal among copper (Cu), silver (Ag), gold (Au), and nickel (Ni) to allow the bottom heat transfer metal layers 19, 27, and 37 and the metal plate 60 illustrated in FIGS. 1 to 4 to be soldered. This is because the surface of copper (Cu), silver (Ag), gold (Au), and nickel (Ni) can be soldered while aluminum (Al) is not. The metal such as copper (Cu), silver (Ag), gold (Au), and nickel (Ni) may be plated on aluminum through electroless plating.

FIG. 4 is an example of configuration of the LED packages 100 line-connected in a serial or parallel circuit form.

With reference to FIG. 4, in order to implement an LED array, one or more FR4 PCBs 61 and a plurality of LED packages 100 are bonded on the low-priced metal plate 60 without a resin layer. The FR4 PCB 61 is bonded on the metal plate 60 by a screw or adhesive. The LED packages 100 is bonded to the metal plate 60 by any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding. A circuit for connecting the LED packages 100 in series or in parallel is formed on the FR4 PCB 61. The LED packages 100 are connected to terminals 61a and 61b formed on the FR4 PCB 61 through the

eternal wirings

53 and 54. The FR4 PCB 61 is connected to an external power source (not shown) through a connector and a cable, so as to be provided with driving power of the LED packages 100 from the external power source.

In the respective embodiments of the present invention, the LED chip of the LED package 100 may be connected to a Zener diode 42 through a metal filler 43 as shown in FIG. 5. In FIG. 5, reference numeral 41 denotes an LED installed in the LED chip. The LED 41 and the Zener diode 42 are connected in parallel through the metal filler 43, and a cathode of the LED 41 is connected to an anode of the Zener diode 42.

In the LED package 100 as shown in FIG. 6, the metal filler 43 filled in a via hole of a package body 50 and having an exposed end is bonded to a metal plate 60 through the foregoing bonding method.

In the LED package 100 as shown in FIG. 6,

electrodes

45 and 46 are protruded to a lower end of the package body 50. In this case, if the LED package 100 is bonded to the metal plate 60 as it is, the

electrodes

45 and 46 of the LED package 100 would come into contact with the metal plate 60 to make the anodes and cathodes of the LED 41 and the Zener diode 42 short-circuited. Thus, in order to prevent the short circuit of the anodes and cathodes, preferably, the

electrodes

45 and 46 are lifted so as to be separated from the metal plate 60 as shown in FIG. 7.

In order to apply external power to the LED package 100 or connect the LED package to a different LED, the

electrodes

45 and 46 of the LED package 100 may be soldered 55 to the

external wirings

53 and 54, respectively.

In order to reliably insulate the

electrodes

45 and 46 with the metal plate 60, the bonded portions of the

electrodes

45 and 46 of the LED package 100 and the

external wirings

53 and 54 are coated with an insulating tape or an insulating tube (or a thermally contracted tube) 56 as shown in FIG. 9, or an insulating pad or insulating sheet 62 may be bonded to the metal plate 60 as shown in FIG. 10. In this case, the insulating pad or insulating sheet 62 must be attached to the portions of the surface other than the bonded surface portion between the lower surface of the LED package 100 and the metal plate 60. The insulating pad or the insulating sheet 62 may be attached only to portions of the metal plate 60 facing the bonded portions of the

electrodes

45 and 46 and the

wirings

53 and 54. The insulating pad or insulating sheet 62 may be implemented as reflective sheets to increase illumination efficiency.

In the case of the LED package 100 as shown in FIG. 11, the plurality of LED packages 100 cannot be bonded to a single metal plate 60. This is because, when the first and second LED packages as shown in FIG. 11 are bonded to the single metal plate 60, the LED 41 and the Zener diode 42 are likely to be short-circuited through the metal filler 43 and the metal plate 60. Thus, in the case of the LED package 100 as shown in FIG. 11, the LED packages 100 must be bonded to the separated metal plates 60 in a one-to-one manner as shown in FIG. 12. In FIG. 12, reference numeral 70 denotes an insulating frame supporting the metal plates 60 on which the LED packages 100 are bonded, respectively, and electrically separating the metal plates 60. Preferably, the insulating frame 70 is made of a material which is electrically an insulator and has high thermal conductivity. The LED packages 100 are connected in series or in parallel through the

external wirings

53 and 54. FIG. 13 is an equivalent circuit diagram of the LED packages connected in series in FIG. 12.

The LED packages having the structure in which the LED 41 and the Zener diode 42 are not connected through the metal filler 43 can be bonded together on the single metal plate 60 as shown in FIG. 14. This is because, the plurality of LED packages 100 can be bonded to the metal plate 60 without a short-circuit problem.

FIG. 15 is a sectional view illustrating an LED device according to a fifth embodiment of the present invention.

With reference to FIG. 15, the LED package 100 according to the fifth exemplary embodiment of the present invention includes a package body 82, an LED chip 76 mounted on the package body 82, a reflector 74 bonded to the package body 82, a lens 72 bonded to the reflector 74, first and second electrodes 80a and80b connected to the LED chip 76 through

internal wirings

78a and 78b, a bottom heat transfer metal layer 86 formed on a lower surface of the package body 82, and plated

layers

88a and 88b formed on the bottom heat transfer metal layer 86.

The package body 82 may be made of a resin, or an LECC or HTCC-based ceramic material. When the package body 82 is made of an NTCC-based ceramic material, e.g., an alumina (Al2O3) ceramic, the package body 82 does not contain low melting point glass. The package body 82 and the bottom heat transfer metal layer 86 can be simultaneously sintered together at a firing temperature of 1,500℃ or higher. The bottom heat transfer metal layer 86 may be selectively made of the foregoing high melting point metal which can be simultaneously fired along with the package body 82.

An anode and a cathode of the LED chip 76 are connected to the first and

second electrodes

80a and 80b through the

internal wirings

78a and 78b, respectively. The

internal wirings

78a and 78b may be selectively formed of gold (Au) wirings. The first and

second electrodes

80a and 80b, penetrating the package body 82, may be protruded from lower portions of the package body 82 through the via holes 81 formed in the package body 82. The first and second electrodes 80 and 80b may be selectively made of the foregoing high melting point metal which can be simultaneously fired with the package body 82 at a high temperature.

The reflector 74 may be formed as a metal ring or as a cylindrical structure with metal such as silver (Ag), or the like, coated thereon to allow light emitted from the LED chip 76 to be concentrated to the lens 72. The reflector 74 reflects light made incident from the LED chip 76 toward the lens 72 to minimize a loss of light. The lens 72 concentrates light made incident from the LED chip 76 and the reflector 74.

The bottom heat transfer metal layer 86 may selectively have a structure in which any one of metal layers among nickel (Ni), copper (Cu), silver (Ag), tin (Sn) and gold (Au) is plated on any one of copper (Cu), silver (Ag), tungsten (W) and molybdenum (Mo). The package body 82, the

electrodes

80a and 80b, and the bottom heat transfer metal layer 86 may be simultaneously fired at a firing temperature of 1,500℃ or higher. In this case, the

electrodes

80a and 80b and the bottom heat transfer metal layer 86 may be selectively made of tungsten (W), molybdenum (Mo), or the like, which can be simultaneously fired with the package body 82 at a high temperature.

The plated layers 88a and 88b, metals which can be soldered, are plated on the bottom heat transfer metal layer 86. The plated layers 88a and 88b may include a single plated layer or a plurality of plated layers. When the plated

layers

88a and 88b are implemented as a plurality of plated layers, a primary plated layer 88a may be nickel (Ni), or nickel (Ni) plated on copper (Cu) plated on the bottom heat transfer metal layer 86 (namely, nickel (Ni) plated on the bottom heat transfer metal layer 86 after the bottom heat transfer metal layer 86 is plated with copper (Cu)). A secondary plated layer 88b is soldered metal, and it may be, for example, one or more of silver (Ag), gold (Au), copper (Cu), and tin (Sn), or an alloy thereof.

The LED package 100 may be bonded to the low-priced metal plate 60 without a resin layer therein through any one of soldering, Ag epoxy, nano-size metal paste and eutectic bonding as shown in FIG. 16. The metal plate 60 may be any one of copper plate, copper alloy plate and an aluminum plate with a surface plated to allow for soldering. The metal plate 60 may be connected to a ground power source so as to be grounded.

FIG. 17 shows an LED package 100 according to a sixth embodiment of the present invention. In the LED package 100 of FIG. 17, any one of the

electrodes

80a and 80b can be directly connected to the LED chip 76 without passing through an internal wiring.

When the LED package 100 as shown in FIG. 15 or FIG. 17 is directly bonded to the metal plate 60, the

end portions

84a and 84b protruded from the lower portions of the LED package 100 may be in contact with the metal plate 60. Then, the anode and the cathode of the LED package 100 may be short-circuited. Thus, in order to prevent the short-circuit, an insulating material 63 is printed on portions of the metal plate 60 facing the

end portions

84a and 84b of the electrodes of the LED package 100 as shown in FIGS. 16, 18, and 19. The insulating material 64 may be formed on the metal plate 60 according to a method of printing solder resist (SR) or photo resist (PR).

A solder material 64 for soldering the LED package 100 to the metal plate 60 is printed only on the portion of the metal plate 60 facing the plated

layers

88a and 88b. In this case, the solder material 64 may be metal containing approximately 96.5% of tin (Sn), 3% of silver (Ag), and 0.5% of copper (Cu).

The insulating material 63 may be patterned to have a bar-like shape as shown in FIG. 18, or a shape of a quadrangular (or polygonal) track as shown in FIG. 19, or a circular (or oval) track. The solder material 64may be patterned to have various shapes such as a circular shape, a polygonal plate shape, or the like, as shown in FIGS. 18 and 19.

One or more LED packages 100 may be bonded to the metal plate 60 according to the foregoing bonding method. When the plurality of LED packages 100 are bonded to the metal plate 60 and the LED packages are connected in series or in parallel, the

external wirings

53 and 54 may be connected to the

electrodes

80a and 80b at upper ends of the respective package bodies of the LED packages 100 in order to prevent short-circuit of the cathodes and anodes. The

external wirings

53 and 54 are connected to the

electrodes

80a and 80b of the neighboring LED packages in series or in parallel and connected to the FR4 PCB bonded to the metal plate 60 as shown in FIG. 4.

Heat generated from the LED chip 76 is transferred to the metal plate 60 through the package body 82, the bottom heat transfer metal layer 86, the plated

layers

88a and 88b, and the electrodes 80a and80b, and released through the metal plate 60. The bottom heat transfer metal layer 86 and the plated

layers

88a and 88b may be employed in the LED packages 100 of FIGS. 1, 2, 3, and 5 to 9.

In the foregoing embodiments, the main ingredient of the package body 82 may be selected from among Al2O3, MgO, BeO, AlN, SiC and the like, without glass powder. In this case, since the material of the package body 82 does not have glass, it has a high thermal conductivity and is sintered at a high temperature. Since the package body 82 has a relatively high thermal conductivity, the via hole and the metal filled in the via hole within the package bodies in the embodiments of FIGS. 1, 3, and 15 to 17 as described above may be omitted. For example, the via hole and the metal filled in the via hole as shown in FIGS. 15 and 17 may be omitted as shown in FIGS. 20 and 21.

In the foregoing embodiments, when the

package bodies

20, 28, 38, 50, and 82 are made of the HTCC-based ceramic material, the via holes of the

package bodies

20, 28, 38, 50, and 82 may be filled with the high melting point metal such as tungsten (W), molybdenum (Mo), or the like, and simultaneously sintered with the package bodies.

In a different fabrication method, the

package bodies

20, 28, 38, 50, and 82 made of the HTCC-based ceramic material may be sintered at a high temperature in advance, via holes may be formed in the

sintered package bodies

20, 28, 38, 50, and 82 and then filled with metal such as silver (Ag), or the like, and then, a metal layer such as the bottom heat transfer metal layer may be formed on the package

bodies package bodies

20, 28, 38, 50, and 82. In this case, in order to increase an adhesive strength of the metal filled in the via holes of the package bodies and the package bodies, 5 wt% or less of glass frit may be added to the metal filled in the via hole. In the method for sintering the package bodies in advance before the metal layer is formed, the material of the metal layer may be selected from among Ag, Ni, Cu, Au, and the like.

As described above, in the present embodiment, since the low-priced metal plate without a resin layer is bonded to the lower surface of the LED package 100 to release LED heat through the metal plate, a degradation of efficiency of the LED chip due to heat and a reduction in the life span can be prevented to thus improve reliability. Also, in the present exemplary embodiment, a large quantity of light can be obtained with the same power consumption compared with the related art, the number of LED packages and heat sinks required for a light source for illumination can be reduced, a fabrication unit cost can be reduced, and the outer form of a product can become compact and slim. In addition, since the low-priced metal plate and FR4 PCB, instead of a high-priced metal PCB, is used, the fabrication unit cost of the light source of an illumination product can be further reduced.

The LED package according to the present embodiment can be applicable to any illumination light source described in the background of art. Embodiments hereinafter are those implementing a lighting device by using the foregoing LED package 100

FIG. 22 is a sectional view of an LED lighting device according to a first embodiment of the present invention.

With reference to FIG. 22, an LED lighting device according to a first embodiment of the present invention includes a power generator 202, and a plurality of metal plates 60 with LED packages 100 bonded thereto.

The power generator 202 is fixed to a base frame 201 to generate driving power of the LED packages 100. Current from the power generator 202 is supplied to the LED packages 100 through external wirings (not shown). The LED packages 100 may be connected in series between a positive polarity terminal and a negative polarity terminal of the power generator 202.

One or more LED packages 100 are bonded to the metal plates 600 according to the bonding method as described above. The metal plates 60 are bent to allow the LED packages 100 to face downward. Upper ends of the metal plates 60 may be fixed to the base frame 201. The metal plates 60 are low-priced metal plates without a resin layer therein. Thus, heat can be released to the outside through the metal plates without a heat transfer bottleneck phenomenon.

As shown in FIGS. 23 and 24, the metal plates 60 are disposed in a radial form centering around the power generator 202 in a state of being spaced apart by a sufficient interval from the power generator 202, respectively. Heat generated from the power generator 202 is released to the outside along the heat release path between the metal plates 60 according to the natural convection current. Accordingly, since heat from the power generator 202 is discharged to the natural convection current, the heat releasing structure of the power generator 202 can be optimized, and since an increase in the temperature of the metal plates 50 caused by heat from the power generator 202 is minimized, a heat transfer flowing backward to the LED packages 100 through the metal plates 60 can be prevented. The metal plates 60 may be fabricated such that they are flat plates when viewed from a horizontal section as shown in FIG. 23 or they have a bent shape (or twisted shape) as shown in FIG. 24.

In FIGS. 22 and 23, reference numeral 203 denotes a mesh made of an insulating material such as plastic. The mesh 203 may have a shade-like shape covering the metal plates 60 and as such it may be fixed to the base frame 201. The mesh 203 discharges heat generated from the temperature of he metal plates 60 or the power generator 202 to the outside, and protects the internal constituents of the LED lighting device.

The LED lighting device as shown in FIG. 22 can improve the heat releasing structure of the power generator 202 and the LED packages 100, but it may cause a hot spot phenomenon because LED light is directly irradiated to a user. The hot spot phenomenon may increase dazzling and fatigue to the user and lower the degree of freedom in designing the indoor illumination environment. Thus, in order to solve the hot spot problem, the LED lighting device according to the present invention can be implemented to have an indirect illumination structure.

With reference to FIGS. 24 to 27, an LED lighting device according to a second embodiment of the present invention includes the power generator 202, the plurality of metal plates 60 with LED packages bonded thereon, and a reflector 90. The mesh 203 may have a shade-like shape covering the metal plates 60 and as such it may be fixed to the base frame 201.

One or more LED packages 100 are bonded to the metal plates 60, respectively, according to the foregoing bonding method. The metal plates 60 are bent such that a light emission surface of the LED packages 100 faces the reflector 90. Accordingly, the light emission surface of each of the LED packages 100 faces the reflector 90. As shown in FIGS. 23 and 24, the metal plates 60 are disposed in a radial form based on the power generator 202 to induce a natural convection current release of heat generated from the power generator 202.

The reflector 90 is selectively made of metal, metal-coated plastic, and mirror, and may selectively have a parabolic shape as shown in FIG. 25, a flat plate-like shape as shown in FIG. 26, and an embossed parabolic shape as shown in FIG. 27. The degree of reflection of the reflector 90 may be adjustable according to the material of the reflector 90 and a surface roughness processing method. The reflector 90 is fixed between the metal plates 60, maintaining the space between the metal plates 60, and reflects light from the LED packages 100 to implement indirect illumination.

FIG. 28 is an exploded perspective view of the LED lighting device according to the second embodiment of the present invention. FIG. 29 is a sectional view of the LED lighting device of FIG. 28 in which an LED package, a metal plate, a concentration block are assembled.

With reference to FIGS. 28 and 29, the LED lighting device according to the second exemplary embodiment of the present invention includes a metal plate 60 with an LED package 100 bonded thereto and a concentration block 300 disposed on the metal plate 60.

The concentration block 300 may be formed by a plastic or resin injection-molding method. A lens insertion hole 301 allowing a lens of the LED package 100 to pass therethrough is formed on the concentration block 300 to expose a light emission surface of the LED package 100, and a sloped face 300a maybe formed to concentrate LED light. The sloped face 300a may have a flat face as shown in FIG. 28, or may be a curved surface. The angle of the sloped face 300a may be set within the range from 0°~ 60° according to the application fields and usage purposes of the LED lighting device. In order to increase the reflectance (or reflectivity), metal or a material having a high reflectance may be coated on the sloped face 300a. The concentration block 300 may be fastened to a housing (401 in FIG. 35) through a screw or a hook, or may be fastened to the metal plate 60 through a screw or a screwless fastening method. Concentration blocks 300 corresponding to the number of the metal plates 60 may be assembled in the LED lighting device. Also, the plurality of concentration blocks 300 may be integrated into a single component.

In the LED lighting device as shown in FIGS. 28 and 29, the light emission surfaces of the LED packages and the sloped faces of the concentration blocks 300 face downward as shown in FIG. 35. Accordingly, the LED lighting device as shown in FIGS. 28 and 29 can be mounted in a reversed state on the concentration block 300 fixed to the housing (401 in FIG. 35), so it can be assembly by being simply mounted on the concentration block 300 without screw fastening or without using an adhesive. A wiring insertion hole 66 may be formed on the metal plate 60 to allow the

external wirings

53 and 54 to be withdrawn to the outside.

A plurality of LED lighting devices as shown in FIGS. 28 and 29 can be configured as shown in FIGS. 30 to 35. As shown in FIGS. 30 to 34, the LED packages 100 are assembled on the same plane and connected to positive polarity and negative polarity terminals (+, -) of the power generation circuit. A mesh 310 made of an insulating material such as plastic may be disposed between the metal plate 60 and a rear cover (402 in FIG. 35. The mesh 310 prevents the LED packages 100, the metal plates 60, and the concentration blocks 300 from being contaminated and allows heat from the LED packages 100 and the metal plates 60 to outwardly pass therethrough.

The

external wirings

53 and 54 are connected by pins and connectors 57. The neighboring LED packages 100 are connected by the

external wirings

53 and 54, and connected to the power generator (403 in FIG. 35) or an inverter as shown in FIG. 31.

In the LED lighting device illustrated in FIG. 30, the LED packages 100 may be disposed in a matrix form as shown in FIG. 31. In FIG. 31, one LED package 100 is bonded to one metal plate 60.

FIG. 32 is a sectional view of an LED lighting device according to a third embodiment of the present invention.

With reference to FIG. 32, an LED lighting device according to the third embodiment of the present invention includes the metal plate 60 with the LED packages 100 bonded thereto and concentration modules disposed on the metal plate 60.

The LED packages 100 are connected through the

external wirings

53 and 54, and also connected between the positive polarity terminal and the negative polarity terminal of the power generator (403 in FIG. 35).

As shown in FIG. 33, a certain number of LED packages 100 may be bonded to a single metal plate 60. As shown in FIG. 33, the LED packages bonded together to the same metal plate 60 are connected in series through the

external wirings

53 and 54, and the first and last LED packages 100 bonded to different metal plates 50 may be connected in parallel to the power generator (403 in FIG. 35) through the

external wirings

53 and 54.

As shown in FIG. 34, a certain number of LED packages 100 may be bonded to a single metal plate 60. As shown in FIG. 34, the LED packages 100 bonded to the neighboring metal plates 60 may be connected in series through the

external wirings

53 and 54, and the LED packages 100 bonded to the first and last metal plates 60 may be connected in parallel to the power generator (403 in FIG. 35) through the

external wirings

53 and 54.

FIG. 35 is a sectional view showing the power generator 403, the housing 401, and the rear cover 402 of the LED lighting devices according to the second and third embodiments of the present invention.

With reference to FIG. 35, the LED lighting device according to the present embodiment includes a metal plate 60 with the LED packages 100 bonded thereto, the power generator 403, the housing 401, the rear cover 402, and a transparent window 404.

The concentration blocks 300 are fixed to the housing 401 such that the sloped face 300a faces downward. A light emission surface of the LED packages 100 bonded to the metal plate 60 faces the transparent window 404. The power generator 403 is fastened to the rear cover 402 or the housing 401. The rear cover 401 and the housing 401 may be made of metal or plastic. The transparent window 404, allowing LED light to be transmitted therethrough, may include a diffusing lens or a condensing lens.

When an LED module which has reached the end of its life span or is defective in the LED lighting device is replaced, even a housewife can easily replace the LED module without the help of a technical maintenance manager. For example, the user can separate the housing 401 from the rear cover 402, separate the concentration block 300 from the housing 401, and then separate the pins and connectors 57, thus separating the problematic LED package 100.

In all the embodiments of the present invention, the LED packages are bonded to the low-priced metal plates without a resin layer. As a result, the bottleneck phenomenon of the heat flow due to the resin layer formed in the existing metal PCB can be prevented, so the heat releasing effect can be maximized, and since the low-priced metal plates, instead of the high-priced metal PCB, are used, the economical efficiency can be improved. The LED device according to embodiments of the present invention can be applicable as any lighting device described in the background art.

In the LED lighting devices illustrated in FIGS. 22 to 27 according to embodiments of the present invention, the metal plates are radially disposed centering around the power generator to induce the natural convection current of heat generated from the power generator. As a result, the luminous efficiency and life span of the LED packages in the LED lighting devices can be improved and lengthened, thus enhancing reliability of the power generator.

In the LED lighting devices illustrated in FIGS. 28 to 35 according to embodiments of the present invention, the LED packages bonded to the metal plate are fabricated into a module structure which can be easily replaced, and the module is assembled along with the concentration block to enhance the concentration effect of the LED lighting devices and easily replace the LED package which has reached the end of its life span.

In the present invention, the LED packages of the present invention are bonded to the metal plates without a resin layer to improve the economical efficiency thereof. The LED device of the present invention can be applicable as any lighting device described in the background art.

Claims

A light emitting diode (LED) device including:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a bottom heat transfer metal layer formed on the bottom of the package body; and

a metal plate bonded to the bottom heat transfer metal layer,

wherein the bottom heat transfer metal layer is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding, and

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate, and

wherein the metal plate comprises only metal without a resin layer.
The LED device of claim 1, wherein the wirings are connected to the electrodes at an upper end of the package body.
The LED device of claim 1, wherein the package body comprises any one of Al2O3, MgO, BeO, AlN, SiC, and

Wherein the bottom heat transfer metal layer has a structure in which any one of metal layers among nickel (Ni), copper (Cu), silver (Ag), tin (Sn), gold (Au) is plated on any one of copper (Cu), silver (Ag), tungsten (W) and molybdenum (Mo).
The LED device of claim 1, further comprising a metal filler filled in a via hole formed in a penetrative manner in the package body.
The LED device of claim 1, further comprising a top heat transfer metal layer installed within the package body such that the top heat transfer metal layer is formed below the LED chip including the LED,

wherein the top heat transfer metal layer is connected to the bottom heat transfer metal layer through the metal filler.
The LED device of claim 1, further comprising a plated layer formed on the bottom heat transfer metal layer,

wherein the plated layer comprises:

a primary plated layer comprising nickel (Ni); and

a secondary plated layer comprising one or more of silver (Ag), gold (Au), copper (Cu), and tin (Sn).
The LED device of claim 1, wherein the metal plate comprises any one of a copper plate, a copper alloy plate or an aluminum plate with metal plated on a surface thereof to allow for soldering.
A light emitting diode (LED) device comprising:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a metal filler filled through a via hole penetrating the package body; and

a metal plate bonded to the metal filler,

wherein the metal filler is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding,

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate, and

wherein the metal plate comprises only metal without a resin layer.
The LED device of claim 8, further comprising a Zener diode installed in the package body.
The LED device of claim 8, wherein the electrodes and wirings are bonded through soldering, and the bonded portions are coated with an insulating member or an insulating member is attached to portions of the metal plate facing the bonded portions of the electrodes and the wirings.
The LED device of claim 8, wherein the metal plate comprises any one of a copper plate, a copper alloy plate and an aluminum plate with metal plated on a surface thereof to allow for soldering.
A lighting device comprising:

metal plates to which one or more LED packages bonded, respectively, the metal plates not having a resin layer; and

a power generator for driving the LED packages,

wherein the metal plates are radially disposed centering around the power generator in order to form a natural convection current passage of heat generated from the power generator.
The lighting device of claim 12, wherein the metal plates are bent such that a light emission surface of each of the LED packages faces downward.
The lighting device of claim 12, further comprising a reflector disposed in the space between the metal plates and reflecting light from the LED packages,

wherein the metal plates are bent such that a light emission surface of each of the LED packages faces the reflector.
The lighting device of claim 12, wherein each of the LED packages comprises:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a bottom heat transfer metal layer formed on the bottom of the package body; and

a metal plate bonded to the bottom heat transfer metal layer,

wherein the bottom heat transfer metal layer is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste and eutectic bonding, and

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate.
The lighting device of claim 12, wherein each of the LED packages comprises:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a metal filler filled through a via hole penetrating the package body; and

a metal plate bonded to the metal filler,

wherein the metal filler is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste, and eutectic bonding, and

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate.
A lighting device comprising:

metal plates to which one or more LED packages bonded, respectively, the metal plates not having a resin layer;

a concentration block having a sloped face for concentrating light from the LED packages;

a power generator for driving the LED packages; and

external wirings for electrically connecting the power generator and the LED packages.
The lighting device of claim 17, further comprising pins and connector for connecting the external wirings.
The lighting device of claim 17, wherein each of the LED packages comprises:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a bottom heat transfer metal layer formed on the bottom of the package body; and

a metal plate bonded to the bottom heat transfer metal layer,

wherein the bottom heat transfer metal layer is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste, and eutectic bonding, and

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate.
The lighting device of claim 17, wherein each of the LED packages comprises:

a package body including an LED installed therein;

a first electrode connected to an anode of the LED;

a second electrode connected to a cathode of the LED;

a first wiring connected to the first electrode;

a second wiring connected to the second electrode;

a metal filler filled through a via hole penetrating the package body; and

a metal plate bonded to the metal filler,

wherein the metal filler is bonded to the metal plate through any one of soldering, Ag apoxy, nano-size metal paste, and eutectic bonding, and

wherein the first and second electrodes are spaced apart from an upper surface of the metal plate.