Light emitting device module and lighting system including the same

Disclosed herein is a light emitting device module comprising: a heat transfer member having a cavity; first conductive layer and second conductive layer contacting the heat transfer member via an insulating layer, the first conductive layer and the second conductive layer being electrically isolated from each other in accordance with exposure of the insulating layer or exposure of the heat transfer member; and at least one light emitting diode electrically connected to the first conductive layer and second conductive layer, the at least one light emitting device is thermally contacted to an exposed portion of the heat transfer member, wherein the heat transfer member has an exposed portion disposed within the cavity between the first conductive layer and the second conductive layer.

This application claims the benefit of Korean Patent Application No. 10-2011-0051331, filed on May 30, 2011 which is hereby incorporated in its entirety by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The embodiment relates to a light emitting device module and a lighting system including the same.

2. Discussion of the Related Art

Light emitting devices, such as light emitting diodes (LEDs) and laser diodes (LDs), which use a Group III-V or Group II-VI compound semiconductor material, may render various colors such as red, green, blue, and ultraviolet by virtue of development of thin film growth technologies and device materials. It may also be possible to produce white light having high efficiency using fluorescent materials or through color mixing. Further, the light emitting devices have advantages, such as low power consumption, semi-permanent lifespan, fast response time, safety, and environmentally friendly properties as compared to conventional light sources, such as fluorescent lamps and incandescent lamps.

Therefore, these light emitting elements are increasingly applied to transmission modules of optical communication units, light emitting diode backlights as a replacement for cold cathode fluorescent lamps (CCFLs) constituting backlights of liquid crystal display (LCD) devices, lighting apparatuses using white light emitting diodes as a replacement for fluorescent lamps or incandescent lamps, headlights for vehicles and traffic lights.

Light emitting device modules are widely used in lighting apparatuses and display apparatuses. Such a light emitting device module is mounted in a package body such that they are electrically connected.

SUMMARY OF THE INVENTION

Accordingly, the embodiment is directed to a light emitting device module and a lighting system including the same, which are capable of achieving an improvement in optical efficiency.

To achieve this object and other advantages and in accordance with the purpose of the embodiment, as embodied and broadly described herein, a light emitting device module comprising: a heat transfer member having a cavity; first conductive layer and second conductive layer contacting the heat transfer member via an insulating layer, the first conductive layer and the second conductive layer being electrically separated from each other in accordance with exposure of the insulating layer or exposure of the heat transfer member; and at least one light emitting device electrically connected to the first conductive layer and second conductive layer, the at least one light emitting device is thermally contacted an exposed portion of the heat transfer member, wherein the heat transfer member has an exposed portion disposed within the cavity between the first conductive layer and the second conductive layer.

At least one of the first conductive layer and the second conductive layer may extend from an edge of the cavity to a side wall of the cavity and then to a bottom portion of the cavity adjacent to the side wall.

At least one of the first conductive layer and the second conductive layer may extend from a longer-axis edge of the cavity to a longer-axis side wall of the cavity and then to a bottom portion of the cavity adjacent to the longer-axis side wall.

The insulating layer has a exposed portion may be disposed between the exposed portion of the heat transfer member and a portion of each of the first conductive layer and second conductive layer disposed on the bottom portion of the cavity.

The light emitting device may be spaced apart from the exposed portion of the insulating layer by a distance of 400 to 500 μm.

The insulating layer may have another exposed portion disposed between the heat transfer member and a portion of each of the first conductive layer and the second conductive layer disposed outside the cavity. The semiconductor light emitting device may be spaced apart from the another exposed portion of the insulating layer by a distance of 150 to 250 μm.

At least one of the first conductive layer and the second conductive layer may extend from a shorter-axis edge of the cavity to a shorter-axis side wall of the cavity and then to a bottom portion of the cavity adjacent to the shorter-axis side wall.

The insulating layer may be exposed between a portion of the first conductive layer disposed on the bottom portion of the cavity and a portion of the second conductive layer disposed on the bottom portion of the cavity to electrically isolate the first conductive layer and second conductive layer.

Portions of the first conductive layer disposed on the bottom portion of the cavity and the second conductive layer disposed on the bottom portion of the cavity may be parallel.

The insulating layer may be exposed between the portions of the first conductive layer and the second conductive layer disposed on the bottom portion of the cavity to electrically isolate the first conductive layer and the second conductive layer.

The light emitting device may be electrically connected to a portion of the first conductive layer and second conductive layer disposed on a bottom of the cavity.

The light emitting device may be spaced apart from the exposed portion of the insulating layer by at least 100 μm.

The exposed portion of the heat transfer member may include an exposed portion exposed at a bottom of the cavity while being 35 to 50% of the entirety of the exposed portion of the heat transfer member.

The exposed portion of the heat transfer member may include an exposed portion exposed at a side wall of the cavity while being 45 to 65% of the entirety of the exposed portion of the heat transfer member.

The exposed portion of the heat transfer member may include an exposed portion exposed outside the cavity while being 10% or less of the entirety of the exposed portion of the heat transfer member.

In another aspect of the embodiment, a light emitting device module includes a heat transfer member having a cavity, an insulating layer formed on a portion of the heat transfer member, first conductive layer and second conductive layer respectively formed on portions of the insulating layer while being electrically isolated from each other, and a light emitting device thermally contacting the heat transfer member and electrically connected to the first conductive layer and the second conductive layer, wherein the heat transfer member is exposed at a portion of the cavity.

At least one of the first conductive layer and the second conductive layer may extend from a longer-axis edge of the cavity to a longer-axis side wall of the cavity and then to a bottom portion of the cavity adjacent to the longer-axis side wall.

The exposed portion of the insulating layer may be disposed between the heat transfer member and a portion of each of the first conductive layer and the second conductive layer disposed on the bottom portion of the cavity.

At least one of the first conductive layer and the second conductive layer may extend from a shorter-axis edge of the cavity to a shorter-axis side wall of the cavity and then to a bottom portion of the cavity adjacent to the shorter-axis side wall. Portions of the first conductive layer disposed on the bottom portion of the cavity and the second conductive layers disposed on the bottom portion of the cavity may be parallel.

In another aspect of the embodiment, a lighting system includes a semiconductor light emitting device module including a heat transfer member having a cavity, first conductive layer and the second conductive layer contacting the heat transfer member via an insulating layer, the first conductive layer and the second conductive layer being electrically isolated from each other in accordance with exposure of the insulating layer or exposure of the heat transfer member, and at least one semiconductor light emitting device electrically connected to the first conductive layer and the second conductive layer, the at least one semiconductor light emitting device is thermally contacted an exposed portion of the heat transfer member, the insulating layer having an exposed portion disposed within the cavity between the first conductive layer and the second conductive layer, at least one circuit board for supplying current to the light emitting device module, and an optical member for transmitting light emitted from the light emitting device module.

DETAILED DESCRIPTION OF THE INVENTION

In the following description of the embodiments, it will be understood that, when an element such as a layer (film), region, pattern, or structure is referred to as being “on” or “under” another element, it can be “directly” on or under another element or can be “indirectly” formed such that an intervening element may also be present. Also, terms such as “on” or “under” should be understood on the basis of the drawings.

In the drawings, dimensions of layers are exaggerated, omitted or schematically illustrated for clarity and description convenience. In addition, dimensions of constituent elements do not entirely reflect actual dimensions thereof.

FIGS. 1A and 1Billustrate light emitting device modules according to first and second embodiments, respectively.

In the light emitting device module according to each embodiment, a light emitting device240is disposed in a cavity formed at a heat transfer member210. The light emitting device240may include a vertical light emitting device, a horizontal light emitting device, or a flip-chip type light emitting device. In these embodiments or other embodiments, the light emitting device240may be semiconductor light emitting device, for example light emitting diode. The heat transfer member210may be made of a material having excellent thermal conductivity. For example, copper (Cu) or aluminum may be used for the material of the heat transfer member210.

The light emitting device240may be disposed on a bottom of the cavity formed at the heat transfer member210. The cavity may have side walls extending vertically. In the illustrated embodiments, the side walls of the cavity are outwardly inclined as they extend upwardly such that the width of the cavity is increased as the cavity extends upwardly, when viewing in the drawings.

Although the heat transfer member210, which defines the cavity, is illustrated as being sharply bent, it may be bent in a streamlined shape.

An insulating layer220is formed over the heat transfer member210. The insulating layer220may be made of, for example, polyimide. The insulating layer220may be patterned to expose at least a portion of the heat transfer member210at the bottom of the cavity. That is, the insulating layer220may not be formed on at least a portion of the bottom of the cavity.

A first conductive layer230aand a second conductive layer230bare formed such that the insulating layer220is interposed between the heat transfer member210and the first conductive layer230aand the second conductive layer230b. In accordance with this structure, the first conductive layer230athe and second conductive layer230b, which supply current to the light emitting device240, are electrically insulated from the heat transfer member210by the insulating layer220. This will be described later.

The first conductive layer230aand the second conductive layer230bmay have the same shape as the insulating layer220. However, each of the first conductive layer230aand the second conductive layer230bmay be formed to have an open region at a portion thereof adjacent to a circuit board270, so as to expose a portion of the insulating layer220. This will be described later. The first conductive layer230aand the second conductive layer230bmay be made of a copper foil.

The light emitting device240is electrically connected to the first conductive layer230aand the second conductive layer230b. This electrical connection may be achieved through bonding of wires250as in the illustrated embodiments. A resin layer260fills the cavity to protect the light emitting device240and wires250. A fluorescent substance is contained in the resin layer260. Accordingly, it may be possible to vary the wavelength of light emitted from the light emitting device240.

A portion of the heat transfer member210extends horizontally at a region around a top of the cavity. A circuit board270is connected to the horizontal portion of the heat transfer member210via the insulating layer220and the first conductive layer230aand the second conductive layer230b.

The circuit board270may be coupled to the first conductive layer230aand the second conductive layer230bby a conductive adhesive280. The circuit board270may include a printed circuit board (PCB), a metal PCB (MPCB), or a metal core PCB (MCPCB).

As shown in a portion “A” ofFIG. 1A, the insulating layer220is partially exposed in a region between the cavity and the circuit board270. That is, the first conductive layer230aand the second conductive layer230bare not formed in the above-described region such that they are opened in the region to expose a portion of the insulating layer220corresponding to the region. In this case, the conductive adhesive280may also not be formed on the exposed portion of the insulating layer.

In the embodiment ofFIG. 1B, a reflective layer235is formed on the first conductive layer230aand the second conductive layer230bwithin the cavity. The reflective layer235may be made of a material capable of reflecting light emitted from the light emitting device240in order to send the reflected light to an outside of the cavity. A silver (Ag) may be coated over the reflective layer235.

The heat transfer member210may be coupled to a substrate100via an adhesive layer110. The substrate100may function as a body of the light emitting device module. When the substrate100is made of a metal, it may function as a bracket to support a light source module in a backlight unit or a lighting apparatus.

The adhesive layer110has excellent thermal conductivity. The adhesive layer110may bond the heat transfer member210to the substrate100. When the substrate100is made of a metal to function as a bracket, heat emitted from the light emitting device240is directly transferred to the substrate100because it is unnecessary to use a resin such as polyphthalamide (PPA) in the backlight unit or lighting apparatus.

FIGS. 2 to 6are views illustrating various patterns of the exposed portion of the insulating layer in the light emitting device module according to each of the above-described embodiments, respectively.FIG. 7is an enlarged view corresponding to the portion “A” ofFIG. 1.

As shown in the drawings, the insulating layer220is partially exposed in a region between the circuit board270and the cavity. Of course, portions of the first conductive layer230aor second conductive layer230barranged at opposite sides of the exposed portion of the insulating layer220are electrically connected in order to electrically connect the light emitting device240and the circuit board270.

The insulating layer220may have at least one line pattern in a region adjacent to the circuit board270. At least one of the first conductive layer230aand the second conductive layer230bis formed on at least a portion of the line pattern of the insulating layer220to electrically connect the light emitting device240and the circuit board270.

That is, in the embodiments shown inFIGS. 2 to 6, the first conductive layer230aor second conductive layer230bis formed on portions of the exposed pattern of the insulating layer220.

In the case ofFIG. 2, the insulating layer220is exposed in the form of a single line pattern. In the case ofFIG. 3, the insulating layer220is exposed in the form of two line patterns. In the cases ofFIGS. 4 and 5, the insulating layer220is exposed in the form of two line patterns bent by a certain angle. In the case ofFIG. 6, the insulating layer220is exposed in the form of three line patterns.

Since the insulating layer220is exposed as described above, it may be possible to prevent the conductive adhesive280from penetrating into the cavity after overflowing in a process of bonding the first conductive layer230aand the second conductive layer230band the circuit board270.

The exposed portion of the insulating layer220may have a width d (FIG. 3) of 10 to 50 μm. When the exposed portion is excessively narrow, it may be insufficient to block the conductive adhesive280. On the other hand, when the exposed portion is excessively wide, the light emitting device module may be inefficient, or the design of the light emitting device may be inefficient.

That is, there may be a possibility that a portion of the conductive adhesive280penetrates into the cavity after flowing over the first conductive layer230aand the second conductive layer230b, thereby resulting in discoloration of the resin layer260, or brightness degradation or color sensation variation of light emitted from the light emitting device240. In the illustrated embodiments, however, the conductive adhesive280may be blocked by the exposed portion of the insulating layer220. That is, it is difficult for the conductive adhesive280to flow on the surface of the insulating layer220. As described above, the first conductive layer230aor second conductive layer230bis partially formed in the region where the insulating layer220is exposed, in order to electrically connect the light emitting device240and the circuit board270.

In the case ofFIG. 2, the insulating layer220is exposed in the form of a straight line pattern. Portions of the first conductive layer230aor second conductive layer230bin regions arranged at opposite sides of the exposed portion of the insulating layer220(first and second regions) are electrically connected. For this electrical connection, the first conductive layer230aor second conductive layer230bis formed on a portion of the exposed straight line pattern of the insulating layer220.

When the insulating layer220is exposed in the form of two or more line patterns, and the shapes of the line patterns are different, as shown inFIGS. 3 to 6, it may be possible to greatly enhance the effect of blocking the conductive adhesive280. In the case ofFIG. 3, the first conductive layer230aor second conductive layer230bis formed on portions of the insulating layer220exposed in the form of two line patterns, and the portions of the first conductive layer230aor second conductive layer230bdo not correspond to each other. The portions of the first conductive layer230aor second conductive layer230bare formed at ends of the line patterns of the insulating layer220opposite to each other, respectively.

That is, each of the first conductive layer230aand the second conductive layer230bhas at least two open regions each having a line pattern, which has a straight line or curved line shape. The portions of each of the first conductive layer230aand the second conductive layer230barranged at opposite sides of each open region (first and second portions) may be electrically connected by at least one connector arranged on each of the different line patterns.

Accordingly, even when the conductive adhesive280penetrates into one exposed line pattern of the insulating layer220, the penetrated conductive adhesive280is difficult to pass through the other exposed line pattern of the insulating layer220because the connectors on the different line patterns do not spatially overlap with each other or do not spatially correspond to each other.

The exposed line patterns of the insulating layer220may have a curved line shape, as shown inFIG. 5, in place of a straight line shape. In this case, the open regions may have the same line pattern shape.

FIGS. 8A to 8Gare views illustrating a method for manufacturing the light emitting device module ofFIG. 1in accordance with an exemplary embodiment.

In accordance with the illustrated method, as shown inFIG. 8A, the insulating layer220and a conductive layer230are first formed over a base substrate290. In this case, the insulating layer220may be fixed to the base substrate290by an adhesive295.

For the conductive layer230, which is bonded to the insulating layer220, a copper foil, to which a polyimide film is bonded, may be used. Since the polyimide film has a small thickness of, for example, 5 μm, it is very advantageous in terms of thermal resistance.

As shown inFIG. 8B, a mask300is formed on the conductive layer230. Using the mask300, the conductive layer230is subsequently patterned.

As the conductive layer230is patterned, three open regions are formed as shown inFIG. 8C. The intermediate open region corresponds to the bottom of the cavity shown inFIG. 1A. The portions of the conductive layer230arranged at opposite sides of the intermediate open region respectively correspond to the first conductive layer230aand the second conductive layer230b. The open regions arranged at opposite sides of the intermediate open region are narrow. These narrow open regions correspond to the exposed portions of the insulating layer220inFIG. 1A.

Thereafter, the insulating layer220is removed from a region corresponding to the bottom of the cavity, as shown inFIG. 8D. In this case, the base substrate290may be patterned along with the layers arranged thereon or may not be patterned because it will be removed in a subsequent process.

As shown inFIG. 8E, the base substrate290is then removed. Subsequently, the heat transfer member210is bonded to the insulating layer220. In this case, the bonding may be achieved using the previously-coated adhesive295or an additional adhesive295. The base substrate290is removed after functioning as a stiffener in the manufacturing procedure.

In this case, the insulating layer220and adhesive295form two layers between the heat transfer member210and the first conductive layer230aand the second conductive layer230b. Since the polyimide of the insulating layer220function as an electrical insulator, and the adhesive295performs a bonding function, an optimal structure capable of achieving an improvement in heat transfer characteristics may be obtained.

Since the heat transfer member210, which has a metal structure thicker than the copper foil, supports the light emitting device240, it may be possible to achieve a remarkable enhancement in reliability. It is also unnecessary to achieve an increase in stiffness using a transparent resin. Accordingly, the material of the resin layer may be selected from more various materials, and thus, cost reduction may be achieved.

Furthermore, it may be possible to achieve a great enhancement in heat dissipation characteristics in accordance with a combination of the insulating layer220and adhesive295. For example, when only the insulating layer220, which is made of polyimide, is applied between the first conductive layer230aand the second conductive layer230b, each of which is made of a copper foil having a thickness of, for example, 18 μm, and the heat transfer member210, which is made of a copper foil having a thickness of 125 μm, the insulating layer220is required to have a thickness of, for example, 20 to 30 μm.

However, when the insulating layer220is applied along with the adhesive295, it may be possible to reduce the thickness of the polyimide insulating layer220. This may be achieved by thinly coating polyimide on the conductive layer230made of a copper foil, to form the insulating layer220. Thus, the thickness of the polyimide insulating layer220may be reduced to 5 μm. Since the polyimide insulating layer220, which has a thickness of 5 μm, provides insulation characteristics, the adhesive295may achieve an enhancement in thermal conductivity.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to form the cavity, as shown inFIG. 8F. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may have a shape in which the edges of the cavity have a curved shape, or a shape in which the edges of the cavity have a point of inflection, as shown inFIG. 1A.

Subsequently, the light emitting device240is mounted on the bottom of the cavity, as shown inFIG. 8G. The light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. In this case, electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255.

FIG. 9is a view illustrating a light emitting device module according to a third embodiment.

The light emitting device module of this embodiment is similar to that ofFIG. 8G, except that the heat transfer member210is boned to the light emitting device240by the adhesive295. Thermal pads may be used for the adhesive295.

FIGS. 10A to 10EandFIG. 11are views illustrating a light emitting device module according to a fourth embodiment and a method for manufacturing the same.

In this embodiment, the base substrate290is not used, different form the embodiment ofFIG. 8A, etc. First, the heat transfer member210is prepared, as shown inFIG. 10A. The heat transfer member210may be made of a material having excellent thermal conductivity. For example, copper (Cu) or aluminum (Al) may be used for the material of the heat transfer member210.

As shown inFIG. 10B, the insulating layer220and the conductive layer230are fixed on the heat transfer member210by the adhesive295.

The conductive layer230is then patterned as shown inFIG. 10C. In this case, the conductive layer230is partially removed to partially expose the insulating layer220. The conductive layer230is divided into first conductive layer230aand the second conductive layer230bby the region S where the insulating layer is exposed.

The process of partially removing the conductive layer230may be achieved using a mask, which is coated, as shown inFIG. 8B, etc., to selectively remove a portion of the conductive layer230. Although opposite ends of the conductive layer230are not removed, namely, portions of the insulating layer220corresponding to the opposite ends are not exposed, in the illustrated embodiment, an open region, through which the insulating layer220is exposed, may be formed around the cavity, as shown inFIG. 8C, etc. This may also be implemented in embodiments to be described later.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to define the cavity, as shown inFIG. 10D. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may be formed to have a shape in which the edges of the cavity have a curved shape, or a shape in which the edges of the cavity have a point of inflection.

The reflective layer235is then formed over the first conductive layer230aand the second conductive layer230b, as shown inFIG. 10E. The reflective layer235may be made of a material capable of reflecting light emitted from the light emitting device240in order to send the reflected light to an outside of the cavity. A silver (Ag) may be coated over the reflective layer235.

Thereafter, the light emitting device240is disposed in the cavity of the heat transfer member210. Thus, a light emitting device module as shown inFIG. 11is completely obtained. Finally, the heat transfer member210of the light emitting device module is coupled to the substrate100via the adhesive layer110.

The substrate100may function as a body of the light emitting device module. When the substrate100is made of a metal, it may function as a bracket to support a light source module in a backlight unit. As shown inFIG. 11, the light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. If the light emitting device240is bonded to the first conductive layer230aand the second conductive layer230busing a conductive material, satisfactory wire bonding may be achieved using only one wire250. Although the light emitting device240is illustrated as being electrically connected to the reflective layer235inFIG. 11, it may be electrically connected to the first conductive layer230aand the second conductive layer230b. This may also be implemented in embodiments to be described later.

Electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255. Thereafter, a resin layer (not shown) fills the cavity to protect the light emitting device240and wires250. In the following embodiments, this is achieved in the same manner as described above.

The embodiment shown inFIG. 11may exhibit degraded heat dissipation effects, as compared to the embodiments ofFIGS. 1A and 1B, because the light emitting device240contacts the heat transfer member210via the first conductive layer230aand the second conductive layer230band the insulating layer220in the embodiment ofFIG. 11. However, the circuit board may be arranged in a region corresponding to the edge portions of the first conductive layer230aand the second conductive layer230baround the cavity, as in the embodiments ofFIGS. 1A and 1B. It may also be unnecessary to form a package body using a polyphthalamide (PPA) resin. Accordingly, the effect of transferring heat emitted from the light emitting device240to the heat transfer member210is great.

FIG. 12is a view illustrating a light emitting device module according to a fifth embodiment. In this embodiment, the light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby two wires250, different from the embodiment ofFIG. 11.

FIG. 13is a view illustrating a light emitting device module according to a sixth embodiment. In this embodiment, the light emitting device240is electrically connected to the first conductive layer230aand the second conductive layer230bwithout using wire bonding. That is, in this embodiment, the light emitting device240is of a flip-chip type so that it may be directly bonded to the first conductive layer230aand the second conductive layer230b.

FIGS. 14 and 15are views illustrating light emitting device module arrays according to exemplary embodiments, respectively.

The above-described light emitting device module may be manufactured from an array of light emitting devices. That is, such a light emitting device array may be separated into individual light emitting device modules after being subjected to a process in which an insulating layer, a conductive layer, etc. are laminated over the heat transfer member.FIG. 14is a view illustrating a state in which the light emitting device array has not been separated into individual light emitting device modules.FIG. 15illustrates a structure in which a plurality of light emitting devices can be disposed in each cavity.

FIG. 16is an enlarged view illustrating a part of the light emitting device module array shown inFIG. 14.FIG. 17shows cross-sectional views respectively taken in directions corresponding to a longer axis B-B′ and a shorter axis C-C′ ofFIG. 16.

Referring toFIG. 16, the first conductive layer230aand the second conductive layer230b, which define a cavity, are shown. Also,FIG. 16shows partial exposure of the insulating layer220in a region around the cavity. The heat transfer member (not shown) may be directly exposed in a region C corresponding to a portion of the bottom of the cavity.

FIG.17(B-B′), which is a cross-sectional view taken along the line B-B′ ofFIG. 16, shows exposure of the heat transfer member210in a central portion of the cavity. However, in FIG.17(C-C′), which is a cross-sectional view taken along the line C-C′ ofFIG. 16, the heat transfer member210is not exposed at the bottom of the cavity. That is, the heat transfer member210is exposed in a short-axis direction within the cavity.

FIGS. 18A and 18Billustrate a light emitting device module according to a seventh embodiment through a plan view and a sectional view, respectively.

In this embodiment, a plurality of light emitting devices240is disposed in the cavity. The light emitting devices are wire-bonded to one another by wires250. The light emitting devices240arranged at opposite side edges of the cavity are wire-bonded to the first conductive layer230aand the second conductive layer230bby wires250.

Similarly to the previous embodiments, the heat transfer member may be exposed at the central region D of the cavity. As shown inFIG. 18B, each light emitting device240directly contacts the heat transfer member210exposed at the bottom of the cavity.

FIGS. 18C and 18Dillustrate a light emitting device module according to an eighth embodiment through a plan view and a sectional view, respectively.

This embodiment is similar to the embodiment ofFIGS. 18A and 18B, except that the heat transfer member210is not exposed at the bottom of the cavity. That is, the insulating layer220and the first conductive layer230aand the second conductive layer230bare completely disposed on the heat transfer member210in a region corresponding to the bottom of the cavity where the light emitting devices240are disposed.

In order to avoid short of current supplied to each light emitting device240, the first conductive layer230aand the second conductive layer230bare removed from a region D corresponding to a portion of the bottom of the cavity. Although the insulating layer220has been shown as being left in the region D, as shown inFIG. 18D, this insulating layer220may be removed to expose the heat transfer member210, as in the previous embodiments.

In the embodiments ofFIGS. 18A to 18D, the light emitting devices240disposed in the cavity may be electrically connected to one another through wire bonding or the like. The light emitting devices240arranged at the opposite side edges of the cavity may be electrically connected to one of the first conductive layer230aand the second conductive layer230bby wire bonding or the like.

FIG. 19is a view illustrating a light emitting device module according to a ninth embodiment. In this embodiment, an open region is formed not only at the first conductive layer230aand the second conductive layer230b, but also at the insulating layer220. The heat transfer member210is exposed in the open region. The shape of the open region is identical to those of the above-described embodiments.

FIG. 20is a view illustrating a light emitting device module according to a tenth embodiment. In this embodiment, an open region is formed not only at the first conductive layer230aand the second conductive layer230band the insulating layer220, but also at the heat transfer member210. The shape of the open region is identical to those of the above-described embodiments. Although each of the first conductive layer230aand the second conductive layer230b, the insulating layer220, and the heat transfer member210is shown as being divided into portions, the actual shape of the open region is a line shape as shown inFIG. 2, etc., and the separated portions of each of the first conductive layer230aand the second conductive layer230b, the insulating layer220, and the heat transfer member210are connected at a portion of the open region.

FIG. 21is a view illustrating a light emitting device module according to an eleventh embodiment.FIGS. 22 and 23are enlarged views corresponding to a portion “A” ofFIG. 21.

The light emitting device module according to this embodiment is similar to that ofFIG. 1. In this embodiment, however, the heat transfer member210is formed with a step at a portion thereof corresponding to a region outside the cavity so that the portion of the heat transfer member210arranged far away from the cavity is lower than the portion of the heat transfer member210arranged adjacent to the cavity.

Since the heat transfer member210has a step as described above, the insulating layer220and the first conductive layer230aand the second conductive layer230b, which have the same pattern as the heat transfer member210, have steps, respectively.

The circuit board270is electrically connected to the first conductive layer230aand the second conductive layer230bby the conductive adhesive280. The circuit board270is disposed on a surface region lower than the step of the heat transfer member210. That is, the circuit board270is disposed on a surface region lower than the steps of the first conductive layer230aand the second conductive layer230b.

In accordance with this structure, each of the heat transfer member210and the first conductive layer230aand the second conductive layer230bhas a portion formed at a higher level between the resin layer260in the cavity and the conductive adhesive270/circuit board280. Accordingly, it may be possible to prevent the resin layer260inside the cavity and the conductive adhesive270outside the cavity from flowing over the first conductive layer230aand the second conductive layer230b.

In particular, when the maximum heights of the first conductive layer230aand the second conductive layer230bbetween the cavity and the circuit board270is greater than the maximum height of the conductive adhesive270and/or the resin layer260, it may be possible to prevent flowing of the conductive adhesive270and resin layer260.

Similarly to the open region formed at a portion of the insulating layer220in the embodiment ofFIG. 1, the steps of the first conductive layer230aand the second conductive layer230bin this embodiment may function as a blocking unit for blocking introduction of an unnecessary material from the outside of the cavity into the cavity.

Hereinafter, the structure of the step will be described in detail. As shown inFIG. 22, the heat transfer member210includes a first step portion210acorresponding to an upper portion of the step, a second step portion210ccorresponding to a lower portion of the step, and a connecting portion210bfor connecting the first and second step portions210aand210b.

The conductive layer230is also patterned to have a step corresponding to the step of the heat transfer member210. Accordingly, the conductive layer230includes a first step portion230dcorresponding to an upper portion of the step, a second step portion230ecorresponding to a lower portion of the step, and a connecting portion230efor connecting the first and second step portions230dand230e.

The insulating layer220, which is interposed between the heat transfer member210and the conductive layer230, is also patterned to have a step corresponding to the steps of the heat transfer member210and conductive layer230. Accordingly, the insulating layer220includes a first step portion220acorresponding to an upper portion of the step, a second step portion220bcorresponding to a lower portion of the step, and a connecting portion220cfor connecting the first and second step portions220aand220b.

When the conductive adhesive270to bond the circuit board280to the conductive layer230has a thickness equal to or less than a thickness or height of the step, it may be possible to prevent the conductive adhesive270from flowing into the cavity. That is, the lower surface of the circuit board280may be flush with or lower than an upper surface of the conductive layer230to the thickness of the conductive adhesive270.

Referring toFIG. 23, the thickness or height of the step is defined by “tc”, and the thickness of the conductive adhesive270is defined by “ts”. Since “ts” is equal to or less than “tc”, the conductive adhesive270may not flow over the conductive layer230toward the cavity.

The thickness tscorresponds to a difference between a height hpat which the conductive adhesive270contacts the circuit board280and a height hcat which the conductive adhesive270contacts the conductive layer230.

Although not shown, a reflective layer may be formed over the conductive layer230within the cavity. The reflective layer may be made of a material capable of reflecting light emitted from the light emitting device240in order to send the reflected light to an outside of the cavity. A silver (Ag) may be coated over the reflective layer.

FIGS. 24A to 24Gare views illustrating a method for manufacturing the light emitting device module ofFIG. 21in accordance with an exemplary embodiment.

In accordance with the illustrated method, as shown inFIG. 24A, the insulating layer220and the conductive layer230are first formed over a base substrate290. In this case, the insulating layer220may be fixed to the base substrate290by an adhesive295.

For the conductive layer230, which is bonded to the insulating layer220, a copper foil, to which a polyimide film is bonded, may be used. Since the polyimide film has a small thickness of, for example, 5 μm, it is very advantageous in terms of thermal resistance.

As shown inFIG. 24B, a mask300is selectively formed on the conductive layer230. Using the mask300, the conductive layer230is subsequently patterned, as shown inFIG. 24C. In this case, the conductive layer230may be divided into two portions, namely, the first conductive layer230aand the second conductive layer230b.

The insulating layer220, base substrate290and adhesive295may be patterned in the same manner as the conductive layer230. The middle region ofFIG. 24D, from which the insulating layer220, etc. are removed, corresponds to the bottom of the cavity inFIG. 21.

As shown inFIG. 24E, the base substrate290is then removed. Subsequently, the heat transfer member210is bonded to the insulating layer220. In this case, the bonding may be achieved using the previously-coated adhesive295or an additional adhesive295. The base substrate290is removed after functioning as a stiffener in the manufacturing procedure.

In this case, the insulating layer220and adhesive295form two layers between the heat transfer member210and each of the first and second conductive layers230aand230b. Since the polyimide of the insulating layer220function as an electrical insulator, and the adhesive295performs a bonding function, an optimal structure capable of achieving an improvement in heat transfer characteristics may be obtained.

Since the heat transfer member210, which has a metal structure thicker than the copper foil, supports the light emitting device240, it may be possible to achieve a remarkable enhancement in reliability. It is also unnecessary to achieve an increase in stiffness using a transparent resin. Accordingly, the material of the resin layer may be selected from more various materials, and thus, cost reduction may be achieved.

Furthermore, it may be possible to achieve a great enhancement in heat dissipation characteristics in accordance with a combination of the insulating layer220and adhesive295. For example, when only the insulating layer220, which is made of polyimide, is applied between each of the first conductive layer230aand the second conductive layer230b, which is made of a copper foil having a thickness of, for example, 18 μm, and the heat transfer member210, which is made of a copper foil having a thickness of 125 μm, the insulating layer220is required to have a thickness of, for example, 20 to 30 μm, when tolerance and bonding force are taken into consideration.

However, when the insulating layer220is applied along with the adhesive295, it may be possible to reduce the thickness of the polyimide insulating layer220. This may be achieved by thinly coating polyimide over the conductive layer230made of a copper foil, to form the insulating layer220. Thus, the thickness of the polyimide insulating layer220may be reduced to 5 μm. Since the thin polyimide insulating layer220, which has a thickness of 5 μm, provides insulation characteristics, the adhesive295may achieve an enhancement in thermal conductivity.

Thereafter, a pressure is applied to the edges of the heat transfer member210to form a step at the heat transfer member210, as shown inFIG. 24F. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also stepped in the same manner as the heat transfer member210.

The above-described step may be formed using a method for pressing the heat transfer member210or the like. The step may be formed as the heat transfer member210is bent in a vertical direction or in a streamlined shape.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to form the cavity. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may have a shape in which the edges of the cavity have a curved shape, as shown inFIG. 9, or a shape in which the edges of the cavity have a point of inflection, as shown inFIG. 21.

Subsequently, the light emitting device240is mounted on the bottom of the cavity, as shown inFIG. 24G. The light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. In this case, electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255.

The above-described light emitting device module may be manufactured from an array of light emitting devices. That is, such a light emitting device array may be separated into individual light emitting device modules after being subjected to a process in which an insulating layer, a conductive layer, etc. are laminated over the heat transfer member.

FIG. 25shows cross-sectional views respectively taken in directions corresponding to a longer axis and a shorter axis in the light emitting device module ofFIG. 21.FIG. 25shows only the heat transfer member210, insulating layer220, and the first conductive layer230aand the second conductive layer230bwhile omitting illustration of the light emitting device, etc.

FIG.25(B-B′), which is a cross-sectional view taken in the longer axis direction of the light emitting device module, shows exposure of the heat transfer member210in a central portion of the cavity. However, in FIG.25(C-C′), which is a cross-sectional view taken in the shorter axis direction of the light emitting device module, the heat transfer member210is not exposed at the bottom of the cavity. That is, the heat transfer member210is exposed in a short-axis direction within the cavity.

FIGS. 26A to 26Fare views illustrating a light emitting device module according to a twelfth embodiment and a method for manufacturing the same.

In this embodiment, the base substrate290is not used, different form the embodiment ofFIG. 24A, etc. Also, the insulating layer220may be fixed to the heat transfer member210without using the adhesive295. In this case, a material having a bonding property such as polyimide may be used for the insulating layer220. In other embodiments, the adhesive295may be dispensed with.

First, the heat transfer member210is prepared, as shown inFIG. 26A. The heat transfer member210may be made of a material having excellent thermal conductivity. For example, copper (Cu) or aluminum (Al) may be used for the material of the heat transfer member210.

As shown inFIG. 26B, the insulating layer220and the conductive layer230are fixed on the heat transfer member210by the adhesive295.

The conductive layer230is then patterned as shown inFIG. 26C. In this case, the conductive layer230is partially removed to partially expose the insulating layer220. The conductive layer230is divided into first conductive layer230aand the second conductive layer230bby the region S where the insulating layer is exposed.

The process of partially removing the conductive layer230may be achieved using a mask to selectively remove a portion of the conductive layer230.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to form the cavity, as shown inFIG. 26D. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may have a shape in which the edges of the cavity have a curved shape, or a shape in which the edges of the cavity have a point of inflection, as shown inFIG. 26D.

The reflective layer235is then formed over the first conductive layer230aand the second conductive layer230b, as shown inFIG. 26E. The reflective layer235may be made of a material capable of reflecting light emitted from the light emitting device240in order to send the reflected light to an outside of the cavity. A silver (Ag) may be coated over the reflective layer235.

Thereafter, a pressure is applied to the edges of the heat transfer member210to form a step at the heat transfer member210, as shown inFIG. 26F. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also stepped in the same manner as the heat transfer member210. In the illustrated case, the reflective layer235is also stepped in the same manner as described above. Of course, the reflective layer235may be formed only within the cavity.

The above-described step may be formed using a method for pressing the heat transfer member210or the like. The step may be formed as the heat transfer member210is bent in a vertical direction or in a streamlined shape.

The detailed structure of the above-described step is identical to the structure described with reference toFIGS. 22 and 23. In the following embodiments, this structure may also be used.

Subsequently, the light emitting device240is mounted on the bottom of the cavity. The light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. In this case, electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255. When a circuit board is coupled to the region where the step is formed, using a conductive adhesive, a light emitting device module is completely obtained. When a resin layer (not shown) fills the cavity ofFIG. 26F, it may be possible to protect the light emitting device240and wires250. In the following embodiments, this is achieved in the same manner as described above.

The embodiment shown inFIG. 26Fmay exhibit degraded heat dissipation effects, as compared to the embodiments ofFIG. 21, because the light emitting device240contacts the heat transfer member210via the first conductive layer230aand the second conductive layer230band the insulating layer220in the embodiment ofFIG. 26F. However, the circuit board may be arranged in a region corresponding to the edge portions of the first conductive layer230aand the second conductive layer230baround the cavity, as in the embodiments ofFIG. 21. It may also be unnecessary to form a package body using a polyphthalamide (PPA) resin. Accordingly, the effect of transferring heat emitted from the light emitting device240to the heat transfer member210is great.

FIGS. 27 and 28are views illustrating light emitting device modules according to thirteenth and fourteenth embodiments, respectively. The embodiment ofFIG. 27is different from the embodiment ofFIG. 26Fin that the light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby two wires250. On the other hand, in the embodiment ofFIG. 28, the light emitting device240is electrically connected to the first conductive layer230aand the second conductive layer230bwithout using wire bonding. That is, in this embodiment, the light emitting device240is of a flip-chip type so that it may be directly bonded to the first conductive layer230aand the second conductive layer230b.

FIG. 29is a sectional view illustrating a light emitting device module according to a fifteenth embodiment.

In this embodiment, a plurality of light emitting devices240is disposed in the cavity. The light emitting devices are wire-bonded to one another by wires250. The light emitting devices240arranged at opposite side edges of the cavity are wire-bonded to the first conductive layer230aand the second conductive layer230bby wires250.

Similarly to the previous embodiments, the heat transfer member may be exposed at the central region C of the cavity. As shown inFIG. 29, each light emitting device240directly contacts the heat transfer member210exposed at the bottom of the cavity. Similarly to the embodiment ofFIG. 21, the heat transfer member210, etc. are stepped at a region outside the cavity.

FIG. 30is a sectional view illustrating a light emitting device module according to a sixteenth embodiment.

This embodiment is similar to the embodiment ofFIG. 29, except that the heat transfer member210is not exposed at the bottom of the cavity. That is, the insulating layer220and the first conductive layer230aand the second conductive layer230bare completely disposed on the heat transfer member210in a region corresponding to the bottom of the cavity where the light emitting devices240are disposed.

In order to avoid short of current supplied to each light emitting device240, the first conductive layer230aand the second conductive layer230bare removed from a region C corresponding to a portion of the bottom of the cavity. Although the insulating layer220has been shown as being left in the region C, as shown inFIG. 30, this insulating layer220may be removed to expose the heat transfer member210, as in the previous embodiments.

FIG. 31is a sectional view illustrating a light emitting device module according to a seventeenth embodiment.

The light emitting device module according to this embodiment is similar to that ofFIG. 1, except that the heat transfer member210has a step due to formation of a cavity, so that it is spaced apart from the substrate100in a region corresponding to the circuit board270, and a support10is formed at the substrate100to withstand the weight of the circuit board270, etc in the region.

FIG. 32Ais an enlarged view corresponding to a portion “F” ofFIG. 31.

Referring toFIG. 32A, the support10is formed at the substrate100in the region corresponding to the circuit board270in order to support the heat transfer member210. Practically, in one light emitting device module, supports10are provided in regions at opposite sides of the cavity, respectively. For simplicity of description, the following description will be given only in conjunction with the support10provided in the region at one side of the cavity.

The support10is disposed on the substrate100in a region where the heat transfer member210does not contact the substrate100. Referring toFIG. 32A, three regions, namely, first to three regions, are defined. In the third region, the substrate100contacts the heat transfer member210via the adhesive layer110. Accordingly, it is unnecessary to dispose the support10in the third region.

In the second region, the heat transfer member210has an inclination. This inclination is caused by the fact that the heat transfer member210has different heights in a region where the cavity is formed and a region where the circuit board is disposed, while extending horizontally in the regions.

In the first region, the heat transfer member210is spaced apart from the substrate100by a certain distance. To this end, in the first region, the support10is formed on the substrate to contact the heat transfer member210, and thus to support the heat transfer member210. In this case, the support member10receives a load applied from the circuit board270to the heat transfer member210. Therefore, at least a portion of the support10should contact the heat transfer member210.

In the case ofFIG. 32A, the support10includes a first support portion10aand a second support portion10b. The support10may include at least one support portion, taking into consideration the magnitude of load and the width of the first region. The support10may be formed of an elastic member to withstand the above-described load. The support10may also be made of a heat transferable material to function as a heat transfer layer capable of transferring heat generated from the circuit board270to the substrate100, which is made of a metal material. Such configurations may also be applied to the embodiments, which will be described later.

The height h of the support10may be equal to the sum of the height difference in the heat transfer member210and the height of the adhesive layer110.

FIGS. 32B to 32Gare enlarged views corresponding to the portion “A” ofFIG. 21to illustrate different embodiments from that ofFIG. 32A.

In the embodiment ofFIG. 32B, the support10is formed in accordance with patterning of the substrate100in the region where the substrate100does not contact the heat transfer member210, namely, the first region. That is, in this embodiment, the support10is made of the same material as the substrate100. In this case, the substrate100is made of a metal, so that it may be possible to increase the area of the substrate100to absorb heat emitted from the circuit board270.

Similarly to the previous embodiment, the support10may include a first support portion10aand a second support portion10bin this embodiment. The support10may include at least one support portion, taking into consideration the magnitude of load and the width of the first region.

The embodiment ofFIG. 32Cis similar to the embodiment ofFIG. 32B, except that the substrate100has the same pattern at the upper and lower surfaces thereof. That is, when it is assumed that the direction of the substrate100to face the heat transfer member210is a first direction of the substrate100, and the direction opposite to the first direction is a second direction of the substrate100, the substrate100has the same pattern in the first and second directions.

The embodiments ofFIGS. 32B and 32Care different in terms of manufacturing processes. That is, in the case ofFIG. 23B, the substrate100may be injection-molded to have the support10, whereas, in the case ofFIG. 32C, the substrate100is injection-molded without having the support100, and then pressed to form the support10.

The embodiment ofFIG. 32Dis similar to the embodiment ofFIG. 32C, except that the pattern forming the support10is subjected to a rounding process. That is, the support10has a round edge to prevent impact from being generated at a portion of the support10contacting the heat transfer member210.

In each embodiment ofFIGS. 32E to 32G, the support10is formed in accordance with patterning of the substrate100. The size or area of the support10in the direction of the support10contacting the heat transfer member210is smaller than that of the support10in the direction of the support10contacting the substrate100. For example, the support10has a shape similar to a trapezoidal shape.

In the above-described structure, the support10, which has a trapezoidal shape, stably supports the heat transfer member210. The support10may be protruded from the substrate100, as in the structure ofFIG. 32A. The support10may also be formed by pressing the substrate100after injection molding thereof to respectively form patterns at two surfaces of the substrate100, as in the structure ofFIG. 32F. Alternatively, the patterns of the substrate100in the structure ofFIG. 32Fmay be subjected to a rounding process to form the structure ofFIG. 32G.

FIGS. 33A to 33Iare views illustrating a method for manufacturing the light emitting device module ofFIG. 31in accordance with an exemplary embodiment.

In accordance with the illustrated method, as shown inFIG. 33A, the insulating layer220and a conductive layer230are first formed over a base substrate290. In this case, the insulating layer220may be fixed to the base substrate290by an adhesive295.

For the conductive layer230, which is bonded to the insulating layer220, a copper foil, to which a polyimide film is bonded, may be used. Since the polyimide film has a small thickness of, for example, 5 μm, it is very advantageous in terms of thermal resistance.

As shown inFIG. 33B, a mask300is selectively formed on the conductive layer230. Using the mask300, the conductive layer230and insulating layer220are subsequently patterned. In this case, the conductive layer230may be divided into two portions, namely, the first conductive layer230aand the second conductive layer230b.

The middle region ofFIG. 33C, from which the insulating layer220, etc. are removed, corresponds to the bottom of the cavity inFIG. 31.

As shown inFIG. 33D, the base substrate290is then removed. Subsequently, the heat transfer member210is bonded to the insulating layer220. In this case, the bonding may be achieved using the previously-coated adhesive295or an additional adhesive295. The base substrate290is removed after functioning as a stiffener in the manufacturing procedure.

In this case, the insulating layer220and adhesive295form two layers between the heat transfer member210and each of the first and second conductive layers230aand230b. Since the polyimide of the insulating layer220function as an electrical insulator, and the adhesive295performs a bonding function, an optimal structure capable of achieving an improvement in heat transfer characteristics may be obtained.

Since the heat transfer member210, which has a metal structure thicker than the copper foil, supports the light emitting device240, it may be possible to achieve a remarkable enhancement in reliability. It is also unnecessary to achieve an increase in stiffness using a transparent resin. Accordingly, the material of the resin layer may be selected from more various materials, and thus, cost reduction may be achieved.

Furthermore, it may be possible to achieve a great enhancement in heat dissipation characteristics in accordance with a combination of the insulating layer220and adhesive295. For example, when only the insulating layer220, which is made of polyimide, is applied between each of the first conductive layer230aand the second conductive layer230b, which is made of a copper foil having a thickness of, for example, 18 μm, and the heat transfer member210, which is made of a copper foil having a thickness of 125 μm, the insulating layer220is required to have a thickness of, for example, 20 to 30 μm, when tolerance and bonding force are taken into consideration.

However, when the insulating layer220is applied along with the adhesive295, it may be possible to reduce the thickness of the polyimide insulating layer220. This may be achieved by thinly coating polyimide over the conductive layer230made of a copper foil, to form the insulating layer220. Thus, the thickness of the polyimide insulating layer220may be reduced to 5 μm. Since the thin polyimide insulating layer220, which has a thickness of 5 μm, provides insulation characteristics, the adhesive295may achieve an enhancement in thermal conductivity.

Thereafter, a pressure is applied to the edges of the heat transfer member210to form a step at the heat transfer member210, as shown inFIG. 33E. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also stepped in the same manner as the heat transfer member210.

The above-described step may be formed using a method for pressing the heat transfer member210or the like. The step may be formed as the heat transfer member210is bent in a vertical direction or in a streamlined shape.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to form the cavity. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may have a shape in which the edges of the cavity have a curved shape or a shape in which the edges of the cavity have a point of inflection, as shown inFIG. 31.

The support, which will be described later, may have a height varying in accordance with the bending degree of the heat transfer member210.

Subsequently, the light emitting device240is mounted on the bottom of the cavity, as shown inFIG. 33F. The light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. In this case, electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255.

Thereafter, a resin layer260fills the cavity to protect the light emitting device240and wires250, as shown inFIG. 33G. A fluorescent substance is contained in the resin layer260. Accordingly, it may be possible to vary the wavelength of light emitted from the light emitting device240.

Subsequently, the support10is prepared to be provided at the substrate100, as shown inFIG. 33H. The support10may be prepared in the form of a separate member made of a material different from that of the substrate100, as in this embodiment, or in the form of a structure integral with the substrate100, as in other embodiments. An adhesive layer110is formed on the substrate100to bond the support10to the substrate100.

As shown inFIG. 33I, the heat transfer member210is boned to the substrate100by the adhesive layer110while coming into contact with the substrate100via the support10. The shape in a portion “F” ofFIG. 33Ihas been described with reference toFIG. 32A, etc.

FIGS. 34A to 34Gare views illustrating a method for manufacturing the light emitting device module ofFIG. 31according to another embodiment.

In this embodiment, the base substrate290is not used, different form the embodiment ofFIG. 33A, etc. Also, the insulating layer220may be fixed to the heat transfer member210without using the adhesive295. In this case, a material having a bonding property such as polyimide may be used for the insulating layer220. In other embodiments, the adhesive295may be dispensed with.

First, the heat transfer member210is prepared, as shown inFIG. 34A. The heat transfer member210may be made of a material having excellent thermal conductivity. For example, copper (Cu) or aluminum (Al) may be used for the material of the heat transfer member210.

As shown inFIG. 34B, the insulating layer220and the conductive layer230are fixed on the heat transfer member210by the adhesive295.

The conductive layer230is then patterned as shown inFIG. 34C. In this case, the conductive layer230is partially removed to partially expose the insulating layer220. The conductive layer230is divided into first conductive layer230aand the second conductive layer230bby the region S where the insulating layer is exposed.

The process of partially removing the conductive layer230may be achieved using a mask, which is coated, as shown inFIG. 34B, etc., to selectively remove a portion of the conductive layer230. Although opposite ends of the conductive layer230are not removed, namely, portions of the insulating layer220corresponding to the opposite ends are not exposed, in the illustrated embodiment, an open region, through which the insulating layer220is exposed, may be formed around the cavity, as shown inFIG. 34C, etc.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to define the cavity, as shown inFIG. 34D. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may be formed to have a shape in which the edges of the cavity have a curved shape, or a shape in which the edges of the cavity have a point of inflection, as shown inFIG. 34D.

The reflective layer235is then formed over the first conductive layer230aand the second conductive layer230b, as shown inFIG. 34E. The reflective layer235may be made of a material capable of reflecting light emitted from the light emitting device240in order to send the reflected light to an outside of the cavity. A silver (Ag) may be coated over the reflective layer235.

The light emitting device240is then disposed in the cavity of the heat transfer member210. Thus, a light emitting device module as shown inFIG. 34Fis completely obtained.

When the heat transfer member210of the light emitting device module is bonded to the substrate100by the adhesive layer110, a light emitting device module as shown inFIG. 34Gis completely obtained. Since it is unnecessary to form a package body using a polyphthalamide (PPA) resin, the effect of transferring heat emitted from the light emitting device240to the heat transfer member210is great.

In this case, the supports10are formed on the substrate100outside the cavity to support the load applied to the heat transfer member210. As described above, circuit boards (not shown) may be arranged on the first conductive layer230aand the second conductive layer230bcorresponding to the supports10, respectively.

In a light emitting device module according to an eighteenth embodiment ofFIG. 35, the light emitting device240is electrically connected to the first conductive layer230aand the second conductive layer230bwithout using wire bonding. That is, in this embodiment, the light emitting device240is of a flip-chip type so that it may be directly bonded to the first conductive layer230aand the second conductive layer230b.

The above-described light emitting device module may be manufactured from an array of light emitting devices. That is, such a light emitting device array may be separated into individual light emitting device modules after being subjected to a process in which an insulating layer, a conductive layer, etc. are laminated over the heat transfer member. Each of the separated light emitting device modules is then bonded to the bracket. Alternatively, the separation into the individual light emitting device modules may be achieved after the bonding of the heat transfer member to the bracket.

FIG. 36shows cross-sectional views respectively taken in directions corresponding to a longer axis and a shorter axis in the light emitting device module ofFIG. 31.FIG. 36omits illustration of the light emitting device, etc.

FIG.36(B-B′), which is a cross-sectional view taken in the longer axis direction of the light emitting device module, shows exposure of the heat transfer member210in a central portion of the cavity. However, in FIG.36(C-C′), which is a cross-sectional view taken in the shorter axis direction of the light emitting device module, the heat transfer member210is not exposed at the bottom of the cavity. That is, the heat transfer member210is exposed in a short-axis direction within the cavity.

Referring to FIG.36(B-B′), the supports10are formed between the substrate100and the heat transfer member210to support the weights of the circuit boards270, respectively. At the regions shown in FIG.36(C-C′), however, the circuit boards270are not disposed, so that the supports10may not be provided at the regions.

FIG. 37is a sectional view illustrating a light emitting device module according to a nineteenth embodiment.

In this embodiment, a plurality of light emitting devices240is disposed in the cavity. The light emitting devices are wire-bonded to one another by wires250. The light emitting devices240arranged at opposite side edges of the cavity are wire-bonded to the first conductive layer230aand the second conductive layer230bby wires250.

Similarly to the previous embodiments, the heat transfer member may be exposed at the central region C of the cavity. Each light emitting device240directly contacts the heat transfer member210exposed at the bottom of the cavity.

Circuit boards (not shown) may be disposed on the first conductive layer230aand the second conductive layer230bin regions outside the cavity, respectively. Supports10are disposed on the substrate100beneath the regions outside the cavity, respectively, to support the heat transfer member210.

FIG. 38is a sectional view illustrating a light emitting device module according to a twentieth embodiment.

This embodiment is similar to the embodiment ofFIG. 37, except that the heat transfer member210is not exposed at the bottom of the cavity. That is, the insulating layer220and the first conductive layer230aand the second conductive layer230bare completely disposed on the heat transfer member210in a region corresponding to the bottom of the cavity where the light emitting devices240are disposed.

In order to avoid short of current supplied to each light emitting device240, the first conductive layer230aand the second conductive layer230bare removed from a region C corresponding to a portion of the bottom of the cavity. Circuit boards (not shown) may be disposed on the first conductive layer230aand the second conductive layer230bin regions outside the cavity, respectively. Supports10are disposed on the substrate100beneath the regions outside the cavity, respectively, to support the heat transfer member210.

FIG. 39is a perspective view illustrating a light emitting device module according to a twenty-first embodiment.

In this embodiment, two light emitting devices240are disposed in the cavity. Wires are connected to two electrode pads242and244provided at each light emitting device240, respectively. The two light emitting devices240are connected to the first conductive layer230aand the second conductive layer230bby wires, respectively. The light emitting devices240are electrically connected to each other via a third conductive layer258, which is of an island type.

Electrode pads255are formed at each of the first conductive layer230aand the second conductive layer230bconnected to respective light emitting devices240by wires. A resin layer260fills the cavity to protect the light emitting devices240and wires.

Similarly to the above-described embodiments, each of the first conductive layer230aand the second conductive layer230bis partially patterned in a region between the cavity and an external circuit board (not shown) to expose a portion of the insulating layer220in this embodiment.

FIG. 40illustrates in detail the relations of the layers in the light emitting device module. The heat transfer member210defines the cavity by a portion thereof. The cavity is indicated by a solid line.

The first conductive layer230aand the second conductive layer230bare disposed on the heat transfer member210via the insulating layer220, and are electrically isolated from each other. The insulating layer220is disposed in a region where the first conductive layer230aand the second conductive layer230bare separated from each other. Thus, the insulating layer220prevents the first conductive layer230aand the second conductive layer230bfrom being electrically connected.

In the region where the first conductive layer230aand the second conductive layer230bare separated from each other, the heat transfer member210and insulating layer220are exposed. The light emitting devices240are disposed in the exposed region. Although the exposed region does not correspond to the cavity, the portions thereof where respective light emitting devices240are disposed overlap with the cavity. The light emitting devices240may be electrically connected to the first conductive layer230aand the second conductive layer230b, respectively.

That is, inFIG. 40, the cavity corresponds to a region including the bottom and side wall indicated by solid lines, whereas the exposed region of the heat transfer member210corresponds to a region where the first conductive layer230aand the second conductive layer230band insulating layer220are not shown.

The insulating layer220is exposed in the exposed region of the heat transfer member210and boundary regions of the first conductive layer230aand the second conductive layer230b. The regions where the insulating layer220is exposed are distributed the bottom and side wall of the cavity and the regions outside the cavity.

The insulating layer220is made of an insulating material such as polyimide. The exposed insulating layer220may be spaced apart from the light emitting device240by at least 100 μm in order to prevent light emitted from the light emitting device240from being absorbed into the insulating layer220, and thus to prevent degradation of optical efficiency.

In this embodiment, the insulating layer220is exposed in the form of line patterns in regions outside the cavity at opposite sides of the cavity. Circuit boards may be disposed outside the exposed linear portions of the insulating layer220, respectively.

That is, at least one of the first conductive layer230aand the second conductive layer230bextends from an edge of the cavity in a longer-axis direction (a lateral direction inFIG. 40) to a side wall of the cavity in the longer-axis direction and then to a portion of the bottom of the cavity adjacent to the longer-axis side wall.

Also, the insulating layer220extends from the longer-axis edge of the cavity to the longer-axis side wall of the cavity and then to a portion of the bottom of the cavity adjacent to the longer-axis side wall. The insulating220may be exposed between each of the portions of the first conductive layer230aand the second conductive layer230bdisposed on the bottom of the cavity and the heat transfer member210. InFIG. 40, the distance “a” represents the distance between the light emitting device, for example, LED1, and the portion of the insulating layer220exposed between each of the portions of the first conductive layer230aand the second conductive layer230bdisposed on the bottom of the cavity and the heat transfer member210. The distance “a” may be 400 to 500 μm.

In this embodiment, two light emitting devices LED1and LED2are disposed in the cavity. When it is assumed that, inFIG. 40, the lateral width of the bottom of the cavity is “w”, the light emitting device LED1is arranged at a position spaced apart from a left side wall of the cavity by a distance of w/4, whereas the light emitting device LED2is arranged at a position spaced apart from the left side wall of the cavity by a distance of 3w/4. If it is assumed that n light emitting devices LED1to LEDn are disposed on the bottom of the cavity, the n light emitting devices LED1to LEDn may be arranged at positions spaced apart from the left side wall of the cavity by distances of w/2n, 3w/2n, . . . , and (2n−1)w/2n, respectively.

InFIG. 40, the distance “b” represents the distance between the light emitting device, for example, LED2, and the portion of the insulating layer220exposed between each of the portions of the first conductive layer230aand the second conductive layer230bdisposed outside the cavity and the heat transfer member210.

The light emitting device, for example, LED1, may be arranged at a central portion of the bottom of the cavity when viewed in a vertical direction inFIG. 40. InFIG. 40, the distance between the light emitting device LED1and one longitudinal wall of the cavity, for example, an upper longitudinal wall of the cavity, is equal to the distance between the light emitting device LED1and the other longitudinal wall of the cavity, for example, a lower longitudinal wall of the cavity.

The distance “b” may be 150 to 250 μm. When the distances “a” and “b” are increased, it may be possible to reduce the amount of light absorbed into the insulating layer220after being emitted from the light emitting device. In this case, however, an increase in the cost of materials used in wire boding and a difficulty in processes may occur.

As shown inFIG. 40, each of the first conductive layer230aand the second conductive layer230bextend partially from the shorter-axis edge of the cavity to the shorter-axis side wall of the cavity and then to a portion of the bottom of the cavity adjacent to the shorter-axis side wall. The first conductive layer230aand the second conductive layer230bare also disposed between the two light emitting devices240.

Here, the shorter-axis direction corresponds to a vertical direction inFIG. 44. The first conductive layer230aand the second conductive layer230bdisposed on the bottom of the cavity between the two light emitting devices240extend in parallel.

The insulating layer220is exposed between the portions of the first conductive layer230aand the second conductive layer230bdisposed on the bottom of the cavity between the light emitting devices240, thereby electrically isolating the first conductive layer230aand the second conductive layer230bfrom each other. As shown inFIG. 40, the light emitting devices240are electrically connected to respective portions of the first conductive layer230aand the second conductive layer230bdisposed on the bottom of the cavity between the light emitting devices240.

In this embodiment, the exposed portion of the heat transfer member210at the bottom of the cavity may be 35 to 50% of the exposed region of the cavity. The exposed portion of the heat transfer member210at the side wall of the cavity may be 45 to 65% of the exposed region of the cavity. The portion of the heat transfer member210disposed outside the cavity may be 10% or less of the entirety of the region where the heat transfer member210is exposed.

A portion of the insulating layer220is disposed at the edge of the region where the heat transfer member210is exposed. Accordingly, it may be possible to reduce absorption of light emitted from the light emitting devices, and to appropriately achieve wire bonding of the light emitting devices.

FIGS. 41A to 41Fare views illustrating a method for manufacturing the light emitting device module ofFIG. 39in accordance with an exemplary embodiment.

In accordance with the illustrated method, as shown inFIG. 41A, the insulating layer220is first formed over a base substrate290. In this case, the insulating layer220may be fixed to the base substrate290by an adhesive295.

A polyimide film is formed on the insulating layer220to a thickness of, for example, 5 μm. Accordingly, it is very advantageous in terms of thermal resistance. As shown in a lower portion ofFIG. 41A, the insulating layer220is patterned to have two open regions.

The patterning of the insulating layer220may be carried out before or after the bonding of the insulating layer220to the base substrate290.

Thereafter, the first conductive layer230aand the second conductive layer230bare disposed on the insulating layer220, as shown inFIG. 41B. The first and second layers230aand230bhas been patterned to be electrically isolated from each other. The insulating layer220is exposed in a region where the first and second layers230aand230bare electrically isolated.

Subsequently, the first conductive layer230aand the second conductive layer230bare partially cut out to form cut-out portions232, as shown inFIG. 41C. Each cut-out portion232may be formed at a boundary region of the side wall of the cavity or a boundary region between the side wall of the cavity and the region outside the cavity. In accordance with this structure, when the heat transfer member210is bent or curved, the first conductive layer230aand the second conductive layer230bmay closely contact the bent or curved portions of the heat transfer member210.

As shown inFIG. 41D, the base substrate290is then removed. Subsequently, the heat transfer member210is bonded to the insulating layer220. In this case, the bonding may be achieved using the previously-coated adhesive295or an additional adhesive295. The base substrate290is removed after functioning as a stiffener in the manufacturing procedure.

In this case, the insulating layer220and adhesive295form two layers between the heat transfer member210and each of the first and second conductive layers230aand230b. Since the polyimide of the insulating layer220function as an electrical insulator, and the adhesive295performs a bonding function, an optimal structure capable of achieving an improvement in heat transfer characteristics may be obtained.

Since the heat transfer member210, which has a metal structure thicker than the copper foil, supports the light emitting device240, it may be possible to achieve a remarkable enhancement in reliability. It is also unnecessary to achieve an increase in stiffness using a transparent resin. Accordingly, the material of the resin layer may be selected from more various materials, and thus, cost reduction may be achieved.

Furthermore, it may be possible to achieve a great enhancement in heat dissipation characteristics in accordance with a combination of the insulating layer220and adhesive295. For example, when only the insulating layer220, which is made of polyimide, is applied between each of the first conductive layer230aand the second conductive layer230b, which is made of a copper foil having a thickness of, for example, 18 μm, and the heat transfer member210, which is made of a copper foil having a thickness of 125 μm, the insulating layer220is required to have a thickness of, for example, 20 to 30 μm, when tolerance and bonding force are taken into consideration.

However, when the insulating layer220is applied along with the adhesive295, it may be possible to reduce the thickness of the polyimide insulating layer220. This may be achieved by thinly coating polyimide over the conductive layer230made of a copper foil, to form the insulating layer220. Thus, the thickness of the polyimide insulating layer220may be reduced to 5 μm. Since the thin polyimide insulating layer220, which has a thickness of 5 μm, provides insulation characteristics, the adhesive295may achieve an enhancement in thermal conductivity.

Thereafter, a pressure is applied to the edges of the heat transfer member210to form a step at the heat transfer member210, as shown inFIG. 41E. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also stepped in the same manner as the heat transfer member210.

The above-described step may be formed using a method for pressing the heat transfer member210or the like. The step may be formed as the heat transfer member210is bent in a vertical direction or in a streamlined shape.

Thereafter, a pressure is applied to the heat transfer member210to bend the heat transfer member210, and thus to form the cavity. At this time, the insulating layer220and the first conductive layer230aand the second conductive layer230bare also bent. The cavity may have a shape in which the edges of the cavity have a curved shape or a shape in which the edges of the cavity have a point of inflection.

Subsequently, the light emitting device240is mounted on the bottom of the cavity, as shown inFIG. 41F. The light emitting device240is wire-bonded to the first conductive layer230aand the second conductive layer230bby the wires250. In this case, electrode pads255may be formed on the first conductive layer230aand the second conductive layer230b. The wires250are bonded to the electrode pads255.

The above-described light emitting device module may be manufactured from an array of light emitting devices. That is, such a light emitting device array may be separated into individual light emitting device modules after being subjected to a process in which an insulating layer, a conductive layer, etc. are laminated over the heat transfer member.

FIGS. 42A to 42Eare views illustrating a method for manufacturing the light emitting device module ofFIG. 39in accordance with another exemplary embodiment. In this embodiment, the adhesive250may dispensed with when polyimide is used for the insulating layer220, and the polyimide functions as an adhesive. Referring toFIG. 42E, a resin layer260fills the cavity.

FIG. 43is a view illustrating a light emitting device module according to a twenty-second embodiment.

In this embodiment, the light emitting device240is electrically connected to the first conductive layer230aand the second conductive layer230bwithout using wire bonding. That is, in this embodiment, the light emitting device240is of a flip-chip type so that it is directly bonded to the first conductive layer230aand the second conductive layer230b.

Hereinafter, a lighting apparatus and a backlight unit will be described as an embodiment of a lighting system in which one of the above-described light emitting device module is arranged.FIG. 44is an exploded perspective view illustrating a lighting apparatus including the light emitting device module according to one of the above-described embodiments.

The lighting apparatus includes a light source600for projecting light, a housing400in which the light source600is mounted, a heat dissipation unit500to dissipate heat generated from the light source600, and a holder700for coupling the light source600and heat dissipation unit to the housing400.

The housing400includes a socket connection part410connected to an electric socket (not shown), and a body part420connected to the socket connection part410. The light source600is received in the body part420. A plurality of air holes430may be formed through the body part420.

Although a plurality of air holes430are formed through the body part420of the housing400in the illustrated case, a single air hole430may be formed through the body part420. Although the plural air holes430are circumferentially arranged, various arrangements thereof may be possible.

The light source600includes a circuit board610and a plurality of light emitting device modules650mounted on the circuit board610. Here, the circuit board610may be shaped to be fitted in an opening formed at the housing400. Also, the circuit board610may be made of a material having high thermal conductivity so as to transfer heat to the heat dissipation unit500, as will be described later.

The holder700is disposed under the light source600. The holder700includes a frame and air holes. Although not shown, an optical member may be disposed under the light source600so as to diffuse, scatter or converge light projected from the light emitting device modules650of the light source600.

The above-described lighting apparatus, which employs the above-described light emitting device modules according to one of the above-described embodiments, exhibits an improvement in brightness because it is possible to reduce the amount of light absorbed into the insulating layer of each light emitting device module after being emitted from the corresponding light emitting device. Also, since the distance between each of the first conductive layer (lead frame) and the light emitting device in each light emitting device module is appropriate, it may be possible to reduce the cost of materials used in wire boding and to secure convenience in the manufacturing process.

FIG. 45is a view illustrating a display apparatus including the light emitting device module according to one of the above-described embodiments.

As shown inFIG. 45, the display apparatus according to the illustrated embodiment, which is designated by reference numeral800, includes a light source module, a reflective plate820provided on a bottom cover810, a light guide plate840disposed in front of the reflective plate820to guide light emitted from the light source module830to a front side of the display apparatus800, first and second prism sheets850and860disposed in front of the light guide plate840, a panel870disposed in front of the second prism sheet860, and a color filter880disposed in front of the panel870.

The light source module includes a circuit board830and light emitting device modules835mounted on the circuit board830. Here, a printed circuit board (PCB) may be used as the circuit board830. The light emitting device module835may have the above-described configuration.

The bottom cover810serves to receive the constituent elements of the display apparatus800. The reflective plate820may be provided as a separate element, as shown inFIG. 45, or may be provided as a material having high reflectivity is coated over a rear surface of the light guide plate840or a front surface of the bottom cover810.

Here, the reflective plate820may be made of material having high reflectivity and capable of being formed into an ultra thin structure. Polyethylene terephthalate (PET) may be used for the reflective plate820.

The light guide plate840serves to scatter light emitted from the light source module so as to uniformly distribute the light throughout all regions of a liquid crystal display apparatus. Therefore, the light guide plate840may be made of a material having high refractivity and transmissivity. The material of the light guide plate840may include polymethylmethacrylate (PMMA), polycarbonate (PC) or polyethylene (PE).

The first prism sheet850may be formed by coating with a polymer exhibiting light transmittance and elasticity over one surface of a base film. The first prism sheet850may have a prism layer having a plurality of three-dimensional structures in the form of a repeated pattern. Here, the pattern may be a stripe type in which ridges and valleys are repeated.

The second prism sheet860may have a similar structure to the first prism sheet850. The second prism sheet860may be configured such that the orientation direction of ridges and valleys formed on one surface of the base film of the second prism sheet860is perpendicular to the orientation direction of the ridges and valleys formed on one surface of the base film of the first prism sheet850. Such a configuration serves to uniformly distribute light transmitted from the light module and the reflective sheet820toward the entire surface of the panel870.

Although not shown, a protective sheet may be provided on each of the prism sheets850and860. The provision of the protective sheet may be achieved by forming a protective layer including light-diffusing particles and a binder at each surface of the base film in each of the prism sheets850and860.

The prism layer may be made of a polymer selected from the group consisting of polyurethane, styrene-butadiene copolymer, polyacrylate, polymethacrylate, polymethyl methacrylate, polyethyleneterephthalate elastomer, polyisoprene and polysilicon.

Although not shown, a diffusion sheet may be disposed between the light guide plate840and the first prism sheet850. The diffusion sheet is made of a polyester or polycarbonate-based material. The diffusion sheet may maximally increase a light projection angle through refraction and scattering of light incident from the display apparatus.

The diffusion sheet may include a support layer including a light diffusing agent, and first and second layers formed on a light emitting surface (in the direction of the first prism sheet) and a light incident surface (in the direction of the reflective sheet) The first and second layers do not include a light diffusing agent.

The support layer may include 0.1 to 10 parts by weight of a siloxane-based light diffusing agent having an average particle size of 1 to 10 μm and 1 to 10 parts by weight of an acryl-based light diffusing agent having an average particle size of 1 to 10 μm, based on 100 parts by weight of a resin including a mixture of a methacrylate-styrene copolymer and methacrylate methyl-styrene copolymer.

The first and second layers may include 0.01 to 1 part by weight of an ultraviolet absorbing agent and 0.001 to 10 parts by weight of an antistatic agent, based on 100 parts by weight of a methacrylate methyl-styrene copolymer resin.

The support layer of the diffusion sheet has a thickness of 100 to 10,000 μm. Each layer may have a thickness of 10 to 1,000 μm.

In the illustrated embodiment, the optical sheet may include a combination of the diffusion sheet, the first prism sheet850and the second prism sheet860. However, the optical sheet may include other combinations, for example, a microlens array, a combination of a diffusion sheet and a microlens array, and a combination of a prism sheet and a microlens array.

A liquid crystal display panel may be used as the panel870. Further, instead of the liquid crystal display panel870, other kinds of display devices requiring light sources may be provided.

The display panel870is configured such that a liquid crystal layer is located between glass substrates, and polarizing plates are mounted on both glass substrates so as to utilize polarizing properties of light. Here, the liquid crystal layer has properties between a liquid and a solid. That is, in the liquid crystal layer, liquid crystals which are organic molecules having fluidity like the liquid are regularly oriented, and the liquid crystal layer displays an image using change of such molecular orientation due to an external electric field.

The liquid crystal display panel used in the display apparatus is of an active matrix type, and uses transistors as switches to adjust voltage applied to each pixel.

The color filter880is provided on the front surface of the panel870, and transmits only an R, G or B light component of light projected from the panel870per pixel, thereby displaying an image.

The above-described lighting apparatus, which employs the above-described light emitting device modules according to one of the above-described embodiments, exhibits an improvement in brightness because it is possible to reduce the amount of light absorbed into the insulating layer of each light emitting device module after being emitted from the corresponding light emitting device. Also, since the distance between each of the first conductive layer (lead frame) and the light emitting device in each light emitting device module is appropriate, it may be possible to reduce the cost of materials used in wire boding and to secure convenience in the manufacturing process.

In the light emitting device module according to one of the embodiments of the present invention and the lighting system using the light emitting device, the insulating layer, which includes a polyimide film, is opened at the top of the cavity. Accordingly, the amount of light absorbed into the insulating layer after being emitted from the light emitting device is reduced, so that an enhancement in optical efficiency is achieved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiment without departing from the spirit or scope of the embodiment. Thus, it is intended that the embodiment covers the modifications and variations of this embodiment provided they come within the scope of the appended claims and their equivalents.