Light source module and backlight unit having the same

The present invention relates to a light source module, which has excellent lighting efficiency and is slim, and a backlight unit having the same. The present invention comprises a light emitting unit electronically connected to a substrate through a bottom surface; a wavelength conversion unit formed on the light emitting unit; and a reflection unit formed on the light emitting unit, wherein the reflection unit has a light emitting surface through which light from the light emitting unit is emitted, the light emitting surface being formed by exposing at least one surface of the wavelength conversion unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national stage of International Application No. PCT/KR2014/009214, filed on Sep. 30, 2014, and claims priority from and the benefit of Korean Patent Application No. 10-2013-0116633, filed on Sep. 30, 2013, and Korean Patent Application No. 10-2014-0131772, filed on Sep. 30, 2014, which are incorporated herein by reference for all purposes as if fully set forth herein.

BACKGROUND

Field

Exemplary embodiments of the present disclosure relate to a light source module and a backlight unit including the same, and, more particularly, to a light source module providing good luminous efficacy while realizing a slim structure and improved external appearance, and a backlight unit including the same.

Discussion of the Background

A typical backlight unit is generally used in surface lighting devices for providing light to a liquid crystal display.

A backlight unit provided to the liquid crystal display is classified into a direct type and an edge type according to locations of light emitting devices.

Development of the direct type backlight unit has started with the advent of liquid crystal displays of 20″ or more, and the direct type backlight unit includes a plurality of light sources disposed on a lower surface of a diffusing plate, such that an entire surface of a liquid crystal display panel is directly illuminated with light emitted from the light sources. Such a direct type backlight unit has higher efficiency in use of light than the edge type backlight unit and is generally used in large liquid crystal displays requiring high brightness.

The edge type backlight unit is generally applied to relatively small liquid crystal displays, such as monitors for laptop computers and desktop computers, and has advantages in terms of good uniformity of light, long lifespan, and thickness of liquid crystal displays.

Recently, a novel edge type backlight unit wherein light emitting diode packages providing advantages in terms of low power consumption and a slim structure are mounted on a substrate and disposed on an inner surface of the backlight unit is proposed in the related art.

However, the edge type backlight unit including the light emitting diode packages has a limitation in thickness reduction of the backlight unit with gradually increasing demand for a slimmer backlight unit, and has difficulty in use of highly efficient light emitting diode chips due to deterioration in heat dissipation by the light emitting diode packages.

SUMMARY

Exemplary embodiments of the present disclosure provide a light source module and a backlight unit including the same, in which a light guide plate includes a receiving portion for receiving a light emitting diode chip, thereby realizing slimness of the backlight unit while improving luminous efficacy thereof.

Exemplary embodiments of the present disclosure provide a light source module and a backlight unit including the same, in which an incident plane of a light guide plate is formed to face an exit plane of a light emitting diode chip, thereby improving luminous efficacy.

In accordance with one exemplary embodiment, a light source module includes: a light emitting diode chip electrically connected to a substrate through a bottom surface thereof; a wavelength conversion portion formed on the light emitting diode chip; a reflective portion formed on the light emitting diode chip, wherein the reflective portion exposes at least one plane of the wavelength conversion portion to form an exit plane through which light emitted from the light emitting diode chip is discharged.

The light source module according to this exemplary embodiment includes a plurality of light emitting diode chips arranged therein.

In the light source module according to this exemplary embodiment, the light emitting diode chip is mounted on the substrate through flip-chip bonding or surface mount technology (SMT).

In the light source module according to this exemplary embodiment, the light emitting diode chip includes: a first semiconductor layer doped with a first conductive type dopant; an active layer formed under the first semiconductor layer; a second semiconductor layer doped with a second conductive type dopant and formed under the active layer; a first electrode electrically connected to the first semiconductor layer; a second electrode electrically connected to the second semiconductor layer; a first electrode pad electrically connected to the first electrode; and a second electrode pad electrically connected to the second electrode, and may be electrically connected to the substrate through the first electrode pad and the second electrode pad.

In accordance with another exemplary embodiment, a light source module includes: a light emitting module including a plurality of light emitting diode chips including a wavelength conversion portion and arranged in one direction, and a reflective portion formed on the light emitting diode chips, wherein the plurality of light emitting diode chips is electrically connected to a substrate through bottom surfaces thereof and the reflective portion exposes at least one plane of the light emitting module to form an exit plane through which light emitted from the light emitting module is discharged.

In the light source module according to this exemplary embodiment, the light emitting module has a rectangular parallelepiped shape and at least two of the light emitting diode chips are arranged in a major axis direction of the light emitting module.

In the light emitting module according to this exemplary embodiment, at least one of the light emitting diode chips is arranged in a minor axis direction of the light emitting module.

In accordance with a further exemplary embodiment, a backlight unit includes: a light guide plate; and a light source module disposed on at least one side of the light guide plate and emitting light, wherein the light source module includes a light emitting diode chip electrically connected to a substrate through a bottom surface thereof; a wavelength conversion portion formed on the light emitting diode chip; and a reflective portion formed on the light emitting diode chip, the reflective portion exposing at least one plane of the wavelength conversion portion to form an exit plane through which light emitted from the light emitting diode chip is discharged.

In the backlight unit according to this exemplary embodiment, the light guide plate includes a receiving portion receiving the light source module, and the receiving portion includes an incident plane facing the exit plane of the light source module.

In the backlight unit according to this exemplary embodiment, the receiving portion is provided to at least one corner of the light guide plate.

In the backlight unit according to this exemplary embodiment, the reflective portion forms at least two planes adjoining each other as exit planes and the receiving portion includes at least two incident planes facing the two exit planes.

In the backlight unit according to this exemplary embodiment, the receiving portion is provided to at least one side of the light guide plate.

In the backlight unit according to this exemplary embodiment, the reflective portion forms at least three planes adjoining each other as exit planes and the receiving portion includes at least three incident planes facing the three exit planes.

In the backlight unit according to this exemplary embodiment, the light source module includes a plurality of light emitting diode chips arranged therein.

In the backlight unit according to this exemplary embodiment, the light emitting diode chip is mounted on the substrate by flip-chip bonding or surface mount technology (SMT).

In the backlight unit according to this exemplary embodiment, the light emitting diode chip includes: a first semiconductor layer doped with a first conductive type dopant; an active layer formed under the first semiconductor layer; a second semiconductor layer doped with a second conductive type dopant and formed under the active layer; a first electrode electrically connected to the first semiconductor layer; a second electrode electrically connected to the second semiconductor layer; a first electrode pad electrically connected to the first electrode; and a second electrode pad electrically connected to the second electrode, and may be electrically connected to the substrate through the first electrode pad and the second electrode pad.

In accordance with yet another exemplary embodiment, a backlight unit includes: a light guide plate; and a light source module disposed on at least one side of the light guide plate and emitting light, wherein the light source module includes a plurality of light emitting diode chips including a wavelength conversion portion and arranged in one direction to be electrically connected to a substrate through a bottom surface thereof, and a reflective portion formed on the light emitting diode chips, and the reflective portion exposes at least one plane of the light emitting module to form an exit plane through which light emitted from the light emitting module is discharged.

Exemplary embodiments of the present disclosure provide a light source module and a backlight unit including the same, in which a light guide plate includes a receiving portion for receiving a light emitting diode chip, thereby realizing slimness of the backlight unit while improving luminous efficacy thereof.

Exemplary embodiments of the present disclosure provide a light source module and a backlight unit including the same, in which an incident plane of a light guide plate is formed to face an exit plane of a light emitting diode chip, thereby improving luminous efficacy.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so as to fully convey the spirit of the present disclosure to those skilled in the art. Accordingly, the present disclosure is not limited to the embodiments disclosed herein and can also be implemented in different forms. In the drawings, widths, lengths, thicknesses, and the like of elements can be exaggerated for clarity and descriptive purposes. Throughout the specification, like reference numerals denote like elements having the same or similar functions. It should be understood that various modifications, changes, and alterations can be made without departing from the spirit and scope of the present disclosure, as limited only by the appended claims and equivalents thereof

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so as to be easily realized by those skilled in the art to which the present disclosure pertains.

FIG. 1is a perspective view of a light source module according to an exemplary embodiment of the present disclosure andFIG. 2is a side-sectional view of the light source module according to an exemplary embodiment of the present disclosure.

Referring toFIG. 1andFIG. 2, a light source module100according to an exemplary embodiment includes a light emitting diode chip110, a wavelength conversion portion120, a reflective portion130, and a circuit board140.

The circuit board140includes substrate pads141a,141belectrically connected to the light emitting diode chip110, and bumps150a,150bdisposed on the substrate pads141a,141b. The circuit board140may be a metal printed circuit board (PCB) having an advantage in terms of heat dissipation, without being limited thereto. The circuit board140may have a bar shape having a major axis and a minor axis.

Although the light source module is illustrated as having a single light emitting diode chip in this exemplary embodiment, the light source module may include a plurality of light emitting diode chips arranged therein in other exemplary embodiments, as shown inFIG. 7andFIG. 9.

The light emitting diode chip110includes a growth substrate111and a semiconductor stack113. The light emitting diode chip110may be directly mounted on the circuit board140by flip bonding or surface mount technology (SMT) to be electrically connected to the circuit board140. In this exemplary embodiment, electrode pads37a,37bexposed on a lower surface of the light emitting diode chip110are electrically connected to the substrate pads141a,141bvia bumps150a,150b. In this exemplary embodiment, since the light source module100does not use a wire, the light source module100does not require a molding portion for protection of the wire and partial removal of the wavelength conversion portion120to expose bonding pads. Accordingly, the light source module according to the exemplary embodiment adopts the flip-chip type light emitting diode chip, thereby preventing generation of color deviation or bright spots while simplifying a fabrication process, as compared with a light source module employing a light emitting diode chip using a bonding wire.

The wavelength conversion portion120is formed on the light emitting diode chip110. That is, the wavelength conversion portion120may surround not only an exit plane EA of the light emitting diode chip110but also an upper surface and side surfaces thereof. As used herein, the exit plane EA refers to a plane of the light emitting diode chip110through which light emitted from the light emitting diode chip110is discharged. That is, the wavelength conversion portion120may be formed on the light emitting diode chip110including a plane corresponding to the exit plane EA, only on some planes of the light emitting diode chip110including the exit plane EA, or on all of the upper and side surfaces of the light emitting diode chip110in other exemplary embodiments.

The wavelength conversion portion120includes phosphors. The phosphors can convert wavelengths of light emitted from the light emitting diode chip110. The wavelength conversion portion120is coated onto the light emitting diode chip110such that the upper surface and side surfaces of the light emitting diode chip110are covered by the wavelength conversion portion120with a constant thickness. A region of the wavelength conversion portion120covering the upper surface of the light emitting diode chip110may have the same or different thickness than a region of the wavelength conversion portion120covering the side surfaces of the light emitting diode chip110. In addition, a region of the wavelength conversion portion120covering the exit plane EA through which light exits may have a different thickness than a region of the wavelength conversion portion120covering the side surfaces and upper surface of the light emitting diode chip110excluding the exit plane EA.

The reflective portion130covers an upper surface and side surfaces of the wavelength conversion portion120excluding at least one plane of the light emitting diode chip110, which is defined as the exit plane EA, (for example, planes120a,120bwhen the light emitting diode chip includes two exit planes). The reflective portion130serves to reflect light, which is subjected to wavelength conversion through the wavelength conversion portion120, towards the exit plane EA. That is, the reflective portion130serves to guide light to be discharged through the exit plane EA of the light source module100. That is, the reflective portion130is formed on other planes excluding the exit plane EA of the light source module100, thereby providing a function of guiding light to be discharged through the exit plane EA of the light source module100.

The reflective portion130may be directly formed on the light emitting diode chip110, and in some exemplary embodiments, the reflective portion130may be formed after formation of the wavelength conversion portion120on the light emitting diode chip110.

The light source module100according to the exemplary embodiment can concentrate light in the direction of the exit plan EA of the light source module100using the reflective portion130formed on the light emitting diode chip110and exposing at least one plane of the light emitting diode chip110as the exit plane EA.

In the light source module100, the light emitting diode chip110is directly mounted on the circuit board140through flip bonding or SMT, thereby realizing high efficiency and miniaturization of the light source module100, as compared with a typical package type light source module using a wire.

Furthermore, the light source module100according to the exemplary embodiment is advantageous in terms of thickness reduction, as compared with a typical package type light source module using a wire.

Referring toFIG. 3andFIG. 4, the structure of the light emitting diode chip will be described in more detail.

FIG. 3is a plan view of the light emitting diode chip shown inFIG. 1andFIG. 4is a cross-sectional view of the light emitting diode chip taken along line I-I′ ofFIG. 3.

Referring toFIG. 3andFIG. 4, the light emitting diode chip according to the exemplary embodiment includes a growth substrate111and a semiconductor stack113.

The semiconductor stack113includes a first conductive type semiconductor layer23formed on the growth substrate111and a plurality of mesas M formed on the first conductive type semiconductor layer23and separated from each other.

Each of the mesas M includes an active layer25and a second conductive type semiconductor layer27. The active layer25is interposed between the first conductive type semiconductor layer23and the second conductive type semiconductor layer27. The light emitting diode chip includes reflective electrodes30on each of the mesas M.

As shown in the drawings, the plural mesas M have an elongated shape and extend parallel to each other in one direction. With this structure, the plurality of mesas M having the same shape can be easily formed in a plurality of chip regions on the growth substrate111.

The reflective electrodes30may be formed on each of the mesas M after the plurality of mesas M is formed, without being limited thereto. Alternatively, the reflective electrodes30may be formed on the second conductive type semiconductor layer27after growth of the second conductive type semiconductor layer27, and before formation of the mesas M. The reflective electrodes30cover substantially the entire upper surface of each of the mesas M and have substantially the same shape as the shape of the mesa M in plan view.

The reflective electrodes30include a reflective layer28and may further include a barrier layer29. The barrier layer29may cover an upper surface and side surfaces of the reflective layer28. For example, the barrier layer29may be formed to cover the upper and side surfaces of the reflective layer28by forming a pattern of the reflective layer28, followed by forming the barrier layer29thereon. For example, the reflective layer28may be formed through deposition and pattering of Ag, Ag alloy, Ni/Ag, Ni/Zn/Ag, or TiO/Ag layers. The barrier layer29may be formed of Ni, Cr, Ti, Pt, Rd, Ru, W, Mo, TiW, or combinations thereof and prevents metallic materials of the reflective layer28from diffusing or being contaminated.

After formation of the plurality of mesas M, an edge of the first conductive type semiconductor layer23may also be etched. As a result, an upper surface of the growth substrate111can be exposed. A side surface of the first conductive type semiconductor layer23may be slanted.

The light emitting diode chip according to the exemplary embodiment further includes a lower insulation layer31covering the plurality of mesas M and the first conductive type semiconductor layer23. The lower insulation layer31has openings that allow electrical connection to the first conductive type semiconductor layer23and the second conductive type semiconductor layer27in a predetermined region. For example, the lower insulation layer31may include openings that expose the first conductive type semiconductor layer23and openings that expose the reflective electrodes30.

The openings may be placed in a region between the mesas M and near the edge of the reflective electrodes30, and may have an elongated shape extending along the mesas M. The openings are restrictively disposed on the mesas M and placed near the same side of the mesas.

The light emitting diode chip according to the exemplary embodiment includes a current spreading layer33formed on the lower insulation layer31. The current spreading layer33covers the plurality of mesas M and the first conductive type semiconductor layer23. The current spreading layer33includes openings placed in an upper region of the mesas M and exposing the reflective electrodes30. The current spreading layer33may form ohmic contact with the first conductive type semiconductor layer23through the openings of the lower insulation layer31. The current spreading layer33is insulated from the plurality of mesas M and the reflective electrodes30by the lower insulation layer31.

The openings of the current spreading layer33have a larger area than the openings of the lower insulation layer31in order to prevent the current spreading layer33from being connected to the reflective electrodes30.

The current spreading layer33is formed on a substantially entire upper region of the growth substrate111excluding the openings. With this structure, the light emitting diode chip can achieve easy current spreading through the current spreading layer33. The current spreading layer33may include a highly reflective metal layer such as an Al layer, which may be formed on a bonding layer such as a Ti, Cr or Ni layer. In addition, a protective layer of Ni, Cu or Au having a single layer structure or a combination layer thereof may be formed on the highly reflective metal layer. The current spreading layer33may have a multilayer structure of, for example, Ti/Al/Ti/Ni/Au.

The light emitting diode chip according to the exemplary embodiment includes an upper insulation layer35formed on the current spreading layer33. The upper insulation layer35includes an opening that exposes the current spreading layer33and openings that expose the reflective electrodes30.

The upper insulation layer35may be formed using an oxide insulation layer, a nitride insulation layer, a mixed layer, or alternative layers of these insulation layers, or a polymer such as polyimide, Teflon, and Parylene.

A first electrode pad37aand a second electrode pad37bare formed on the upper insulation layer35. The first electrode pad37ais connected to the current spreading layer33through the openings of the upper insulation layer35and the second electrode pad37bis connected to the reflective electrodes30through the openings of the upper insulation layer35. The first electrode pad37aand the second electrode pad37bmay be used as pads for bump connection or SMT upon mounting a light emitting diode on a circuit board or the like.

The first and second electrode pads37a,37bmay be simultaneously formed by the same process, for example, photolithography and etching technology or lift-off technology. The first and second electrode pads37a,37bmay include a bonding layer, such as a Ti, Cr, or Ni layer, and a highly conductive metal layer, such as an Al, Cu, Ag or Au layer. The first and second electrode pads37a,37bmay be formed such that distal ends thereof are placed on the same plane, thereby allowing the light emitting diode chip to be flip bonded to conductive patterns having the same height on the circuit board.

Then, the growth substrate111is divided into individual light emitting diode chip units, thereby providing light emitting diode chips. The growth substrate111may be removed from the light emitting diode chips before or after dividing into individual light emitting diode chip units.

As such, the light emitting diode chip according to the exemplary embodiment directly flip bonded to the circuit board can realize high efficiency and miniaturization as compared with typical package type light emitting diodes.

FIG. 5is an exploded perspective view of a display including a backlight unit according to an exemplary embodiment of the present disclosure, andFIG. 6is a plan view of a light source module and a light guide plate shown inFIG. 5.

Referring toFIG. 5andFIG. 6, a display according to an exemplary embodiment includes a display panel DP on which an image is displayed, a backlight unit BLU disposed at a rear side of the display panel DP and emitting light, a frame240supporting the display panel DP and receiving the backlight unit BLU, and a top cover280surrounding the display panel DP.

The display panel DP includes a color filter substrate and a thin film transistor substrate disposed to face each other and coupled to each other, so as to maintain a uniform cell gap therebetween. In some exemplary embodiments, the display panel DP may further include a liquid crystal layer between the color filter substrate and the thin film transistor substrate.

Although not shown in detail, the thin film transistor substrate includes a plurality of gate lines and a plurality of data lines intersecting each other to define pixels therebetween, and a thin film transistor disposed in each intersection regions between the gate lines and the data lines and connected in one-to-one correspondence to a pixel electrode mounted on each of the pixels. The color filter substrate includes RGB color filters corresponding to each of the pixels, a black matrix forming a frame of each of the color filters while covering the gate lines, the data lines, and the thin film transistors, and a common electrode covering all of these components. In other exemplary embodiments, the common electrode may be formed on the thin film transistor substrate.

The backlight unit BLU provides light to the display panel DP, and includes a lower cover270open at an upper side thereof, a light source module100disposed at a corner of the lower cover270, and a light guide plate250disposed parallel to the light source module100and converting spot light into sheet light.

In addition, the backlight unit BLU includes optical sheets230disposed on the light guide plate250to diffuse and collect light, and a reflective sheet260disposed under the light guide plate250and reflecting light that travels in a downward direction of the light guide plate250to towards the display panel DP.

The light source module100emits light through adjoining exit planes. As shown inFIG. 6, the exit planes of the light source module100may be defined by two side surfaces thereof. In this exemplary embodiment, the light source module100is placed at each corner of the light guide plate250.

The light guide plate250includes a receiving portion251formed on at least one corner thereof and corresponding to the light source module100. The receiving portion251has a concave shape corresponding to the shape of the light source module100. Specifically, the receiving portion251includes a plane on which light emitted from the light source module100is incident, and this plane faces the exit plane EA and can be defined as an incident plane.

Although the light source modules100are illustrated as being placed at each of the four corners of the light guide plate250in this exemplary embodiment, it should be understood that the present disclosure is not limited thereto, and the light source module100may be provided to at least one corner of the light guide plate250, which adjoin one surface of the light guide plate250. Further, the light source module100may include a plurality of light emitting diode chips as a module therein.

According to another exemplary embodiment, the exit planes of the light source module100may be defined by three side surfaces thereof, as shown inFIG. 7. In this exemplary embodiment, the light source modules100are placed to correspond to each side of the light guide plate250, in addition to the four corners of the light guide plate250.

The light guide plate250includes receiving portions251,252in some regions of the side thereof corresponding to the light source module100. Each of the receiving portions251,252has a concave shape corresponding to the shape of the light source module100and may be formed in plural at the center of the side of the light guide plate250. Specifically, the receiving portions251,252include planes on which light emitted from the light source module100is incident, and each of these planes faces the exit plane EA and can be defined as an incident plane. In this exemplary embodiment, three incident planes may be formed to face three exit planes.

Although the light source module100is illustrated as having the receiving portion252formed at the center of each of four sides of the light guide plate250in this exemplary embodiment, it should be understood that the present disclosure is not limited thereto and the light source module100may be provided to at least one side of the light guide plate250, which adjoins one surface of the light guide plate250, and may be formed in other regions of the side, instead of being formed at the center thereof. Further, the light source module100may include a plurality of light emitting diode chips as a module therein.

Although the number of exit planes and the number of incident planes are illustrated as two and three in the above exemplary embodiments, it should be understood that the present disclosure is not limited thereto and the number of exit planes or incident planes may range from one to five.

As such, in the backlight unit BLU according to the exemplary embodiments of the present disclosure, the light source modules100are provided to the corners of the light guide plate250, thereby enabling reduction in the number of light emitting diode chips while improving an external appearance by realizing slimness of the backlight unit BLU and minimization of a non-display region at an edge of the backlight unit BLU, as compared with a typical backlight unit.

The light source module includes100the light emitting diode chips directly mounted on a circuit board through flip bonding or SMT, thereby realizing high efficiency and miniaturization, as compared with a typical package type light source module using a wire.

FIG. 8is a perspective view of a light source module according to a further exemplary embodiment of the present disclosure andFIG. 9is a cross-sectional view of a light emitting diode chip taken along line II-II′ ofFIG. 8.

FIG. 10andFIG. 11are plan views of the light source module according to exemplary embodiments and a light guide plate including the same.

Referring toFIG. 8toFIG. 11, a light source module300according to a further exemplary embodiment may include a plurality of light emitting diode chips310arranged in one direction. That is, two or more light emitting diode chips310may be arranged in a longitudinal direction of a light emitting module300. Herein, the longitudinal direction of the light emitting module300can be defined as a major axis direction x-x′ thereof. Although not shown in detail, at least one light emitting diode chip310may be arranged in a minor axis direction y-y′ of the light emitting module300. The number of light emitting diode chips310may be set in various ways depending upon the size or brightness of the backlight unit. A wavelength conversion portion320and a reflective portion330may be formed on the plurality of light emitting diode chips310, as described above.

According to yet another exemplary embodiment, the light source module300includes a plurality of light emitting diode chips310including a wavelength conversion portion320and arranged in one direction thereof. That is, two or more light emitting diode chips310may be arranged in the longitudinal direction of the light emitting module300. Herein, the longitudinal direction of the light emitting module300can be defined as a major axis direction x-x′ thereof. Although not shown in detail in the drawings, at least one light emitting diode chip310may be arranged in a minor axis direction y-y′ of the light emitting module300. The number of light emitting diode chips310may be set in various ways depending upon the size or brightness of the backlight unit.

The light source module300includes a reflective portion330covering the light emitting module300. The reflective portion330covers an upper surface and side surfaces of the light emitting module300. The reflective portion330expose two side surfaces320a,320bof the light emitting module300, which adjoin each other. The side surfaces320a,320bexposed by the reflective portion330can be defined as exit planes EA.

The light source module300is placed at one side adjacent one corner of a light guide plate350. Specifically, the light source module300is placed near one corner of the light guide plate350and is parallel to one of side surfaces of the light guide plate350, which adjoin the corner thereof. In addition, the light source module300may be placed parallel to some region of the side surface.

In the light source module300according to the exemplary embodiment, the plurality of light emitting diode chips310is provided in the form of a light emitting module300, whereby the backlight unit according to the exemplary embodiment can reduce the number of light source modules300, as compared with a typical backlight unit, and can realize a slim structure while reducing a non-display region of the backlight unit by minimizing an installation region of the light source module300, thereby improving an external appearance.

FIG. 12is a perspective view of a light source module according to yet another exemplary embodiment of the present disclosure, andFIG. 13is a view of the light source module and the light guide plate shown inFIG. 12.

Referring toFIG. 12andFIG. 13, a light source module400according to this exemplary embodiment includes a light emitting diode chip, a wavelength conversion portion, and a reflective portion130.

The light emitting diode chip and the circuit board140are the same as those of the light source modules according to the above exemplary embodiment, and detailed descriptions thereof will be omitted.

The wavelength conversion portion covers the light emitting diode chip on the circuit board140. The wavelength conversion portion may surround an upper surface and side surfaces of the light emitting diode chip and include phosphors.

The reflective portion130exposes an upper surface and a side surface of the wavelength conversion portion corresponding to an upper surface420aand a side surface420bof the light emitting diode chip, which are defined as exit planes EA and adjoin each other. The reflective portion130serves to reflect light, which is subjected to wavelength conversion through the wavelength conversion portion, towards the exit planes EA. That is, the reflective portion130serves to guide light to be concentrated on the upper surface420aand the side surface420bof the light source module400.

As such, the light source module400according to the exemplary embodiment can concentrate light towards the upper surface420aand the side surface420bof the light source module400using the reflective portion130exposing the upper surface420aand the side surface420badjoining each other.

The exit planes EA of the light source module400correspond to the receiving portion251at a corner of the light guide plate250. The receiving portion251has a concave shape corresponding to the light source module400. Specifically the receiving portion251includes two side surfaces adjoining each other and receiving light emitted from the light source module400. The two side surfaces of the receiving portion251can be defined as incident planes.

Although not shown in the drawings, the light source module400may include at least two light emitting diode chips. The at least two light emitting diode chips may be arranged in the longitudinal direction of the upper surface420aof the light source module400. In addition, at least two light emitting diode chips may be arranged in the longitudinal direction of the side surface420a.

As such, according to the exemplary embodiment, the light source module400is provided at the corner of the light guide plate250, thereby enabling reduction in the number of light emitting diode chips while improving an external appearance through slimness of the backlight unit and minimization of a non-display region at an edge of the backlight unit, as compared with a typical backlight unit.

Furthermore, in the light source module400according to the exemplary embodiment, the light emitting diode chips are directly mounted on the circuit board140through flip bonding or SMT, thereby realizing high efficiency and miniaturization of the light source module400, as compared with a typical package type light source module using a wire.

Although some exemplary embodiments have been described above, it should be understood that the present disclosure is not limited to a particular exemplary embodiment. Further, it should be understood that some features of a certain embodiment may also be applied to other embodiments without departing from the spirit and scope of the invention.