KR20150086759A - Light source module, backlight unit and lightting device having the same - Google Patents

Abstract

Disclosed is a light source module which is thin and can provide uniform light. The light source module includes a circuit board, at least one light emitting diode chip which is mounted on the circuit board by flip chip bonding or surface mount technology (STM), a wavelength conversion part which covers the light emitting diode chip, and a semi-transparent part which is located in the upper part of the wavelength conversion part. A part of light is reflected by placing the semi-transparent part on the upper side of the light emitting device. The other part passes through the semi-transparent part so that light emitted to the upper direction and lateral direction can be uniformly controlled.

Description

TECHNICAL FIELD [0001] The present invention relates to a light source module, a backlight unit having the light source module,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source module, and more particularly, to a light source module capable of realizing thinning and providing uniform light, and a backlight unit and a lighting device having the same.

A general backlight unit is widely used for a display or a surface illuminator for providing light to a liquid crystal display.

BACKGROUND ART [0002] A backlight unit included in a liquid crystal display device is classified into a direct-down type or an edge type according to the position of a light-emitting device.

The direct-type backlight unit has been developed mainly as the size of the liquid crystal display device starts to be enlarged to 20 inches or more, and a plurality of light sources are disposed under the optical sheets to direct light directly to the front of the liquid crystal display panel will be. Such a direct-type backlight unit is mainly used for a large-screen liquid crystal display device which requires a high luminance because the utilization efficiency of light is higher than that of the edge type.

BACKGROUND ART [0002] In recent years, a backlight unit of a direct-down type has been mainly used as a light-emitting device having low power consumption and long lifetime.

However, the light emitting device has a problem that light is concentrated in the upward direction, and uniform brightness can not be realized due to the difference in brightness between the region where the light emitting device is located and the peripheral region. Here, a general direct-type backlight unit realizes a uniform brightness by a method of sufficiently maintaining the interval between the light-emitting device and the optical sheets, but has a problem of not only being difficult to slim but also lowering the light efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide an omni-directional light source module of uniform light.

Another object of the present invention is to provide a backlight unit capable of realizing high efficiency and thinness.

Another object of the present invention is to provide a lighting apparatus of a simplified configuration.

A light source module according to an embodiment of the present invention includes a circuit board; At least one light emitting diode chip mounted on the circuit board by flip chip bonding or SMT (Surface Mount Technology); A wavelength converter for covering the light emitting diode chip; And a transflective portion located above the wavelength conversion portion.

The backlight unit according to another embodiment of the present invention includes at least one light emitting diode chip mounted on a circuit board by flip chip bonding or SMT (Surface Mount Technology), a wavelength converter for covering the light emitting diode chip, A plurality of light emitting devices including a transflective portion disposed on an upper side; And optical sheets positioned on the plurality of light emitting devices.

According to another aspect of the present invention, there is provided a lighting apparatus comprising: a main body; At least one light emitting diode chip mounted on a circuit board by flip chip bonding or SMT (Surface Mount Technology), a light source module including a wavelength converter covering the light emitting diode chip and a transflector located above the wavelength converter, ; And a cover portion covering the light source module.

In the present invention, the transflective portion may be positioned on the upper surface of the light emitting device to reflect part of the light, transmit the other portion, and uniformly adjust the light emitted in the upward direction and the lateral direction.

And the side of the wavelength converter is exposed from the transflective portion.

The light emitting diode chip includes the wavelength converting unit, and a plurality of the light emitting diode chips may be modularized.

The transflective portion includes a white material that reflects a portion of the light and transmits a portion of the light.

The transflective portion includes a plurality of layers, and the plurality of layers have different refractive indices from each other.

In the present invention, a semi-transparent portion is disposed on at least one light-emitting diode chip to reflect a part of light, and transmit the other portion to uniformly control light emitted in an upper direction and a lateral direction.

Accordingly, the present invention provides an omnidirectional light source module of uniform brightness, which is advantageous in reducing the interval between the optical sheets and the light source module, thereby making the backlight unit slimmer.

Further, since the omnidirectional light source module of uniform brightness is provided, the illuminating device having a simplified configuration can be realized.

1 is a cross-sectional view illustrating a light source module according to an embodiment of the present invention.
FIG. 2A is a plan view specifically showing a configuration of the light emitting device of FIG. 1, and FIG. 2B is a cross-sectional view illustrating a light emitting device cut along a line I-I 'of FIG. 2A.
3 is a perspective view illustrating a light emitting device according to another embodiment of the present invention.
4 is an exploded perspective view showing a display device including a backlight unit of the present invention.
5 is a cross-sectional view illustrating a display device cut along the line II-II 'of FIG.
6 is an exploded perspective view showing a lighting device including a light source module of the present invention.
7 is a cross-sectional view showing the illumination device of Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the shapes of components and the like can be exaggeratedly expressed. Like reference numerals designate like elements throughout the specification. Modifications of the components that do not depart from the technical scope of the present invention are not limited thereto and can be defined only by the description of the claims in order to clearly describe the technical idea of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

1 is a cross-sectional view illustrating a light source module according to an embodiment of the present invention.

1, a light source module 100 according to an exemplary embodiment of the present invention includes a light emitting device 110 and a circuit board 140.

The circuit board 140 includes substrate pads 141a and 141b electrically connected to the light emitting device 110 and the bumps 150a and 150b are located on the substrate pads 141a and 141b . The circuit board 140 is not particularly limited, but may be, for example, a metal PCB favoring heat dissipation. The circuit board 140 may be a bar type having a major axis and a minor axis.

The light emitting device 110 includes a light emitting diode chip 111, a wavelength converter 120 covering the light emitting diode chip 111 and a translucent portion 121 disposed on the wavelength converter 120.

The light emitting diode chip 111 includes a growth substrate 112 and a semiconductor stacking unit 113. The light emitting diode chip 111 may be electrically connected to the circuit board 140 directly by flip bonding or SMT (Surface Mount Technology). The electrode pads 37a and 37b exposed on the lower surface of the LED chip 111 and the substrate pads 141a and 141b are electrically connected to each other by the bumps 150a and 150b. Since the light source module 100 of the present invention does not use a wire, a molding part for protecting the wire is not required, and it is not necessary to remove a part of the wavelength conversion layer 120 to expose the bonding pad. Accordingly, by adopting the flip chip type light emitting diode chip 111, the present invention can eliminate the color deviation and luminance unevenness, and simplify the module manufacturing process, as compared with the light emitting diode chip using the bonding wire.

The wavelength conversion unit 120 covers the light emitting diode chip 111. The wavelength conversion unit 120 surrounds the upper surface and side surfaces of the LED chip 111, and the wavelength conversion unit 120 includes a phosphor. The phosphor may convert the wavelength of light emitted from the light emitting diode chip 111. The wavelength conversion unit 120 is coated on the light emitting diode chip 111 and may cover the upper surface and side surfaces of the light emitting diode chip 111 with a predetermined thickness. The wavelength conversion unit 120 may have the same thickness as the area covering the upper surface of the light emitting diode chip 111 and the area covering the side surfaces of the light emitting diode chip 111 and may have different thicknesses. In addition, the wavelength converter 120 may have a different thickness from a region covering the emission surface from which light is emitted, and a region covering the side surfaces and the upper surface except for the emission surface. Here, the emitting surface may correspond to two adjacent side surfaces 120a and 120b of the light emitting diode chip 111.

The transflective portion 121 is located above the wavelength converter 120. That is, the transflective portion 121 exposes the side surfaces of the wavelength conversion portion 120 defined by the emission surface EA of the light emitting device 110. The transflective portion 121 reflects a part of light concentrated in an upward direction from the light emitting diode chip 111 in a lateral direction. That is, the transflective portion 121 uniformly adjusts the light emitted in the upward direction and the lateral direction of the light emitting device 110 by reducing light concentrated in the upward direction of the LED chip 111. The transflective portion 121 may include a white material, and may include at least two or more layers. Here, the plurality of layers may have different refractive indices from each other.

The light source module 100 of the present invention is advantageous in that it is thin in comparison with a light source module of a general package type and the transflective portion 121 is positioned on the upper surface of the light emitting diode chip 111 to reflect a part of light, So that the light emitted in the upward direction and the lateral direction can be uniformly adjusted.

The structure of the light emitting diode chip 111 will be described in more detail with reference to FIGS. 2A and 2B.

FIG. 2A is a plan view specifically showing a configuration of the light emitting device of FIG. 1, and FIG. 2B is a cross-sectional view illustrating a light emitting device cut along a line I-I 'of FIG. 2A.

2A and 2B, the light emitting diode chip of the present invention includes a growth substrate 112 and a semiconductor stacking section 113.

The semiconductor stacking part 113 includes a first conductivity type semiconductor layer 23 formed on the growth substrate 112 and a plurality of mesas M spaced from each other on the first conductivity type semiconductor layer 23 do.

The plurality of mesas M include an active layer 25 and a second conductivity type semiconductor layer 27, respectively. The active layer 25 is located between the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27. [ On the other hand, the reflective electrodes 30 are positioned on the plurality of mesas M, respectively.

The plurality of mesas M may have an elongated shape extending parallel to each other in one direction as illustrated. This shape simplifies the formation of a plurality of mesas M of the same shape in a plurality of chip regions on the growth substrate 112.

The reflective electrodes 30 may be formed on each of the mesas M after the plurality of mesas M are formed. However, the present invention is not limited thereto, and the second conductivity type semiconductor layer 27 may be grown, May be previously formed on the second conductivity type semiconductor layer 27 before forming the second conductivity type semiconductor layers M. The reflective electrode 30 covers most of the upper surface of the mesa M and has substantially the same shape as the planar shape of the mesa M. [

The reflective electrodes 30 may include a reflective layer 28 and may further include a barrier layer 29. The barrier layer 29 may cover the top and side surfaces of the reflective layer 28. For example, the barrier layer 29 may be formed to cover the upper surface and the side surface of the reflective layer 28 by forming a pattern of the reflective layer 28 and forming a barrier layer 29 thereon. For example, the reflective layer 28 may be formed by depositing and patterning Ag, Ag alloy, Ni / Ag, NiZn / Ag, and TiO / Ag layers. The barrier layer 29 may be formed of Ni, Cr, Ti, Pt, Rd, Ru, W, Mo, TiW or a composite layer thereof to prevent the metal material of the reflection layer from being diffused or contaminated.

After the plurality of mesas M are formed, the edges of the first conductivity type semiconductor layer 23 may also be etched. Thus, the upper surface of the growth substrate 112 can be exposed. The side surfaces of the first conductivity type semiconductor layer 23 may also be inclined.

The light emitting diode chip 111 of the present invention further includes a lower insulating layer 31 covering the plurality of mesas M and the first conductivity type semiconductor layer 23. The lower insulating layer 31 has openings for allowing electrical connection to the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27 in a specific region. For example, the lower insulating layer 31 may have openings for exposing the first conductivity type semiconductor layer 23 and openings for exposing the reflective electrodes 30.

The openings may be located near the area between the mesas M and the edge of the substrate 21 and may have an elongated shape extending along the mesas M. [ On the other hand, the openings are located on the upper portion of the mesa M and are biased to the same end side of the mesa.

The light emitting diode chip 111 of the present invention includes a current dispersion layer 33 formed on the lower insulating layer 31. The current spreading layer 33 covers the plurality of mesas M and the first conductivity type semiconductor layer 23. In addition, the current-spreading layer 33 has openings located in the respective upper regions of the mesa M and exposing the reflective electrodes. The current spreading layer 33 may be in ohmic contact with the first conductive semiconductor layer 23 through the openings of the lower insulating layer 31. The current spreading layer 33 is insulated from the plurality of mesas M and the reflective electrodes 30 by the lower insulating layer 31.

The openings of the current spreading layer 33 have a larger area than the openings of the lower insulating layer 31 to prevent the current spreading layer 33 from connecting to the reflective electrodes 30. [

The current spreading layer 33 is formed on almost the entire region of the substrate 31 except for the openings. Therefore, the current can be easily dispersed through the current dispersion layer 33. [ The current spreading layer 33 may include a highly reflective metal layer such as an Al layer and the highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. Further, a protective layer of a single layer or a multiple layer structure such as Ni, Cr, Au or the like may be formed on the highly reflective metal layer. The current-spreading layer 33 may have a multilayer structure of Ti / Al / Ti / Ni / Au, for example.

In the light emitting diode chip of the present invention, the upper insulating layer 35 formed on the current spreading layer 33 is formed. The upper insulating layer 35 has openings for exposing the reflective electrodes 30 together with openings for exposing the current-spreading layer 33.

The upper insulating layer 35 may be formed using an oxide insulating layer, a nitride insulating layer, a mixed layer or a cross layer of these insulating layers, or a polymer such as polyimide, Teflon, or parylene.

A first electrode pad 37a and a second electrode pad 37b are formed on the upper insulating layer 35. [ The first electrode pad 37a is connected to the current spreading layer 33 through the opening of the upper insulating layer 35 and the second electrode pad 37b is connected to the reflective electrodes 30). The first electrode pad 37a and the second electrode pad 37b may be used as a pad for connecting a bump or a pad for SMT to mount a light emitting diode on a circuit board or the like.

The first and second electrode pads 37a and 37b may be formed together in the same process and may be formed using, for example, a photo and etch technique or a lift-off technique. The first and second electrode pads 37a and 37b may include an adhesive layer of, for example, Ti, Cr, Ni, or the like and a high-conductivity metal layer of Al, Cu, Ag, or Au. The first and second electrode pads 37a and 37b may be formed so that their end portions are located on the same plane, so that the light emitting diode chip can be flip-bonded onto a conductive pattern formed at the same height on the circuit board.

Thereafter, the light emitting diode chip is completed by dividing the growth substrate 112 into individual light emitting diode chip units. The growth substrate 112 may be removed from the light emitting diode chips before or after being divided into individual light emitting diode chip units.

As described above, the LED chip of the present invention, which is directly flip-bonded to the circuit board, has the advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light emitting device.

3 is a perspective view illustrating a light emitting device according to another embodiment of the present invention.

As shown in FIG. 3, a light emitting device 210 according to another embodiment of the present invention has a structure in which a plurality of light emitting diode chips 211 are modularized.

The light emitting device 210 includes a wavelength conversion unit 220 covering each of the plurality of light emitting diode chips 211.

The light emitting device 210 includes a transflective portion 221 covering an upper surface of the wavelength conversion portion 220. The transflective portion 221 reflects a part of the light concentrated in the upward direction from the light emitting diode chip 211 in the lateral direction. That is, the transflective portion 221 uniformly adjusts the light emitted in the upward direction and the lateral direction of the light emitting device 210 by reducing light concentrated in the upward direction of the LED chip 211. The transflective portion 221 may include a white material and may include at least two or more layers. Here, the plurality of layers may have different refractive indices from each other.

The light emitting device 210 according to another embodiment of the present invention is a module in which a plurality of light emitting diode chips 211 are modularized to realize thinness and high brightness and a transflective portion 221 is located on the upper surface of the light emitting diode chip 211 It is possible to uniformly adjust the light emitted in the upper direction and the lateral direction by reflecting part of the light and transmitting the other part.

FIG. 4 is an exploded perspective view illustrating a display device including a backlight unit of the present invention, and FIG. 5 is a cross-sectional view illustrating a display device cut along a line II-II 'of FIG.

4 and 5, the display device of the present invention includes a direct-type backlight unit 320 included in a middle- or large-sized display device.

The display device includes a display panel 310, a panel guide 300, and a backlight unit 320.

Although not shown in the drawing, the display device may further include a top cover (not shown) covering the top edge of the display panel 310 and coupled with the backlight unit 320.

The display panel 310 includes a thin film transistor substrate and a color filter substrate bonded together to maintain a uniform cell gap, and a liquid crystal layer interposed between the two substrates.

Although not shown in detail in the drawing, the thin film transistor substrate and the color filter substrate will be described in detail. In the thin film transistor substrate, pixels are defined by a plurality of gate lines and data lines crossing each other, Thin Film Transistors) are connected to the pixel electrodes mounted on the respective pixels in a one-to-one correspondence. The color filter substrate includes color filters of R, G, and B colors corresponding to the respective pixels, and a black matrix for covering the gate lines, the data lines, the thin film transistors, and the like.

The display panel 310 has a gate driving PCB 312 for supplying driving signals to the gate lines and a data driving PCB 313 for supplying driving signals to the data lines. The gate driving PCB 312 is not formed on a separate PCB, but may be formed on a thin film transistor substrate in a COG (Chip On Glass) form.

The gate and data driving PCBs 312 and 313 are electrically connected to the liquid crystal display panel 310 by COF (Chip On Film). Here, the COF may be changed to a TCP (Tape Carrier Package).

The backlight unit 320 includes optical sheets 330, a lower cover 380, a light emitting device 110, and a reflective sheet 370.

The lower cover 380 has a structure in which an upper surface is opened, and has a function of housing the optical sheets 330, the light emitting device 110, and the reflective sheet 370.

The optical sheets 330 include a diffusion sheet, a light condensing sheet, and a protective sheet. Here, the optical sheets 330 may be composed of a single diffusion sheet and two sheets of condensing sheets, or two sheets of diffusing sheets and a single sheet of condensing sheet.

Since the light emitting device 110 is the same as the light emitting device 110 of FIG. 1 according to an embodiment of the present invention, detailed description thereof will be omitted. Here, the light emitting device 110 may be a light emitting device 210 (FIG. 3) according to another embodiment of the present invention.

In the present invention, a semi-transparent portion is disposed on at least one light-emitting diode chip to reflect a part of light, and transmit the other portion to uniformly control light emitted in an upper direction and a lateral direction.

Therefore, since the backlight unit of the present invention provides the omnidirectional light emitting device 110 of uniform brightness, it is advantageous in reducing the interval between the optical sheets 330 and the light emitting device 110, which is advantageous for slimming down the backlight unit 320 .

FIG. 6 is an exploded perspective view showing a lighting apparatus including the light source module of the present invention, and FIG. 7 is a sectional view showing the lighting apparatus of FIG.

6 and 7, the illumination device 400 of the present invention includes a body portion 450, a cover portion 401, and a light source module 410.

The body portion 450 includes a heat dissipating portion and a socket connected to an external power source, though not shown in the figure.

The light source module 410 includes a circuit board 140 and a light emitting device 110 mounted on the circuit board 140.

Since the light emitting device 110 is the same as the light emitting device 110 of FIG. 1 according to an embodiment of the present invention, detailed description thereof will be omitted. Here, the light emitting device 110 may be a light emitting device 210 (FIG. 3) according to another embodiment of the present invention.

In the present invention, a semi-transparent portion is disposed on at least one light-emitting diode chip to reflect a part of light, and transmit the other portion to uniformly control light emitted in an upper direction and a lateral direction.

Therefore, the present invention has an advantage that a lighting device 400 having a simplified configuration can be implemented because it provides uniform light in all directions.

Although various embodiments have been described above, the present invention is not limited to the specific embodiments. In addition, the elements described in the specific embodiments may be applied to the same or similar elements in other embodiments without departing from the spirit of the present invention.

110: Light emitting device 121, 221: Transflective part

Claims (15)

A circuit board;
At least one light emitting diode chip mounted on the circuit board by flip chip bonding or SMT (Surface Mount Technology);
A wavelength converter for covering the light emitting diode chip; And
And a transflective portion disposed on the upper portion of the wavelength conversion portion. The method according to claim 1,
Wherein the wavelength conversion unit exposes a side surface from the transflective portion. The method according to claim 1,
Wherein the light emitting diode chip comprises a plurality of light emitting diode chips, each of the light emitting diode chips includes the wavelength converting portion, adjacent side surfaces of the light emitting diode chips are arranged in contact with each other, The light source module being located. The method according to claim 1,
Wherein the transflective portion comprises a white material that reflects a portion of the light and transmits a portion of the light. The method according to claim 1,
Wherein the transflective portion includes a plurality of layers, and the plurality of layers have different refractive indices from each other. A light emitting device comprising: at least one light emitting diode chip mounted on a circuit board by flip chip bonding or SMT (Surface Mount Technology); a wavelength converting portion covering the light emitting diode chip; and a plurality of light emitting portions device; And
And a plurality of light-emitting devices disposed on the plurality of light-emitting devices. The method of claim 6,
Wherein the wavelength conversion unit exposes a side surface from the transflective portion. The method of claim 6,
Wherein each of the light emitting diode chips includes the wavelength converting portion, adjacent side surfaces of the light emitting diode chips are arranged in contact with each other, and one transflective portion is disposed on the plurality of light emitting diode chips. The method of claim 6,
Wherein the transflective portion comprises a white material that reflects a portion of the light and transmits a portion of the light. The method of claim 6,
Wherein the transflective portion includes a plurality of layers, and the plurality of layers have different refractive indices from each other. A body portion;
At least one light emitting diode chip mounted on a circuit board by flip chip bonding or SMT (Surface Mount Technology), a light source module including a wavelength converter covering the light emitting diode chip and a transflector located above the wavelength converter, ; And
And a cover portion covering the light source module. The method of claim 11,
Wherein the side of the wavelength conversion portion is exposed from the transflective portion. The method of claim 11,
Wherein the light emitting diode chip comprises a plurality of light emitting diode chips, each of the light emitting diode chips includes the wavelength converting portion, adjacent side surfaces of the light emitting diode chips are arranged in contact with each other, The lighting device being located. The method of claim 11,
Wherein the transflective portion comprises a white material that reflects a portion of the light and transmits a portion of the light. The method of claim 11,
Wherein the transflective portion includes a plurality of layers, and the plurality of layers have different refractive indices from each other.

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