KR20120124913A - Light emitting device package and lighting system including the same - Google Patents

Abstract

PURPOSE: A light emitting device package and a lighting system including the same are provided to improve light directional angle and to enhance light extracting efficiency by forming a reflective layer on the side of the circuit board. CONSTITUTION: A pair of lead frames(32,33) is formed on an insulating layer(10). The pair of lead frames is electrically separated. The insulating layer is comprised of polyimide. A heat radiation member is touched with the insulating layer. The insulating layer comprises one or more open areas. A light emitting device(50) is electrically connected to the pair of lead frames. The light emitting device is arranged on an opposite direction of the insulating layer. A pair of circuit boards(110) is electrically connected to the pair of lead frames, respectively.

Description

LIGHT EMITTING DEVICE PACKAGE AND LIGHTING SYSTEM INCLUDING THE SAME}

Embodiments relate to a light emitting device package and an illumination system including the same.

Light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs) using semiconductors of Group 3-5 or 2-6 compound semiconductor materials of semiconductors have been developed using thin film growth technology and device materials. Various colors such as green, blue, and ultraviolet light can be realized, and efficient white light can be realized by using fluorescent materials or combining colors, and low power consumption, semi-permanent life, and quicker than conventional light sources such as fluorescent and incandescent lamps can be realized. It has the advantages of response speed, safety and environmental friendliness.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

BACKGROUND In the lighting device and the display device, a light emitting device package is mounted on a package body and electrically connected thereto.

The embodiment is intended to improve heat dissipation characteristics and directivity of the light emitting device package.

Embodiments include an insulating layer; A pair of lead frames provided on the insulating layer and electrically separated from each other; A light emitting element electrically connected to the pair of lead frames, the light emitting element being disposed in a direction opposite to the insulating layer with respect to the pair of lead frames; And a pair of circuit boards disposed in a direction opposite to the insulating layer with respect to the pair of lead frames, and electrically connected to the pair of lead frames, respectively.

The insulating layer may be made of polyimide.

The light emitting device package may further include a heat dissipation member in contact with the insulating layer.

The insulating layer may have at least one open area.

The light emitting device package may further include a heat dissipation member contacting the insulating layer, and a thermal interface material may be disposed in the open area, and the insulating layer and the heat dissipation member may contact the thermal contact material.

The light emitting device may be disposed on the open area.

The display device may further include a third lead frame disposed between the pair of lead frames and electrically separated from the pair of lead frames, and the light emitting device may be disposed on the third lead frame.

Third lead frames may be separated from the pair of lead frames by at least 50 micrometers each.

The third lead frame may be in contact with the thermal contact material.

Further comprising a resin layer covering the light emitting element, the edge of the resin layer may be formed on the side of the circuit board.

The height of the edge of the resin layer may be lower than the height of the circuit board.

The light emitting device may be wire bonded to the pair of lead frames, and the resin layer may cover the wire.

Another embodiment is an insulating layer; A heat dissipation layer disposed on the insulating layer; A light emitting element on the heat dissipation layer; First and second lead frames spaced apart from the heat dissipation layer and electrically connected to the light emitting devices, respectively; And a pair of circuit boards disposed on the first lead frame and the second lead frame, respectively, and electrically connected to the first lead frame and the second lead frame, respectively.

The heat dissipation layer may be made of the same material as the first lead frame and the second lead frame.

The insulating layer may have at least one open area, and the open area may correspond to the heat dissipation layer.

The heat dissipation member may further include a heat dissipation member contacting the insulating layer, wherein a thermal interface material is disposed in the open area, and the insulating layer and the heat dissipation member may contact the thermal contact material.

Yet another embodiment provides an illumination system including the above-described light emitting device package.

In the light emitting device package according to the embodiment, the cost of the material is reduced, and the heat dissipation characteristics and the light directing angle are improved.

1 is a cross-sectional view of an embodiment of a light emitting device package,
FIG. 2 is a view showing 'A' region of FIG. 1 in detail;
3 is a cross-sectional view of another embodiment of a light emitting device package;
4 to 10 is a view showing an embodiment of a manufacturing method of the light emitting device package of FIG.
11 is a view showing heat emission and light emission of a light emitting device package according to a comparative example,
12 is a view schematically showing heat emission and light emission of the light emitting device package according to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, when described as being formed on the "on or under" of each element, the (up) or down (on) or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. In addition, the size of each component does not necessarily reflect the actual size.

1 is a cross-sectional view of an embodiment of a light emitting device package.

The light emitting device package according to the embodiment includes an insulating layer 10, a pair of lead frames 32 and 33 disposed on the insulating layer 10 and electrically separated from each other, and a pair of lead frames ( 32 and 33, the light emitting device 50 electrically connected to the insulating layer 10 with respect to the pair of lead frames 32 and 33, respectively, and the light emitting layer 10. And a pair of circuit boards 110 disposed in the same direction as the device 50 and electrically connected to the lead frames 32 and 33, respectively.

The insulating layer 10 may be made of an insulating material such as polyimide and may serve as a support layer of the light emitting device package.

In addition, the insulating layer 10 may be provided as a pair separated from each other, the heat transfer layer (ThermalInterface Material, 130) may be disposed in the separated area, that is, the open area of the insulating layer 10 as shown. .

The heat transfer layer 130 is made of a material having excellent thermal conductivity, so that light generated from the light emitting device 50 may be emitted to the heat dissipation member 120 through the heat transfer layer 130.

The light emitting device 50 is disposed to correspond to the open area, and is also arranged to correspond to the heat transfer layer 130 provided in the open area.

The heat dissipation member 120 is disposed under the insulating layer 10, and the adhesive layer 90 may be provided to couple the heat dissipation member 120 and the insulating layer 10 to each other. The heat dissipation member 120 is coupled to the insulating layer 10 separated from each other and the heat transfer layer 130 in the open area.

A third lead frame 31 is disposed between the first lead frame 32 and the second lead frame 33, and the third lead frame 31 is electrically connected to the first and second lead frames 33 and 33. Can be separated.

The first to third lead frames 31 to 33 may be made of a conductive material, for example, copper (Cu), and may have the same composition.

The light emitting device 50 is disposed in contact with the third lead frame 31, and heat generated from the light emitting device 50 is transferred to the heat transfer layer 130 and the heat dissipation member 120 through the third lead frame 31. Therefore, the third lead frame 31 may be made of a material having excellent thermal conductivity. That is, the third lead frame 31 may act as a heat dissipation layer.

The insulating layer 10 may be bonded through the heat dissipation member 120, the first to third lead frames 31 to 33, and the adhesive layers 20 and 90, wherein the adhesive layer 90 is a conductive material or a non-conductive material. Can be.

A circuit board 110 is provided in an edge region of the first lead frame 32 and the second lead frame 33, and the first and second lead frames 32 and 33 and the circuit board 110 are electrically contacted with each other. The first and second lead frames 32 and 33 serve to support the circuit board 110.

Since the circuit board 110 itself has a height of 1 millimeter or more, a cavity having the circuit board 110 as a sidewall may be formed as shown. The resin layer 70 may be formed to include the phosphor 75 in the cavity.

The resin layer 70 may be molded by protecting the light emitting device 50 and the wire 60 electrically connecting the light emitting device 50 to the first and second lead frames 32 and 33.

The resin layer 70 may be made of a light transmissive material such as silicon, and may include the phosphor 75 to convert light in the first wavelength region emitted from the light emitting device 50 into light in the second wavelength region. Although not shown, a filler may be included in the resin layer 70 to prevent the phosphor 75 from being precipitated downward.

An edge of the resin layer 70 is formed in the circuit board 110 so that the circuit board 110 forms a boundary of the resin layer 70. And, the height of the circuit board 110 may be lower than the height of the resin layer 70, at least as shown, the height of the edge of the resin layer 70 should be lower than the height of the circuit board 110.

The reflective layers 40 may be formed on the first to third lead frames 31 to 33 to reflect the light emitted from the light emitting devices in the opening direction. Although not shown, the reflective layer 40 is formed on the side surface of the circuit board 110 forming the sidewalls of the cavity, thereby increasing the light extraction efficiency of the light emitting device package.

FIG. 2 is a diagram illustrating region 'A' of FIG. 1 in detail.

The second lead frame 33 and the third lead frame 31 are spaced apart from each other by a predetermined distance (a). The separation distance may be 50 micrometers or more. If the separation distance is too short, there is a possibility of a short circuit between the lead frames, a distance of 50 micrometers or more is required for the separation process of the lead frame described later.

Although not shown, the first lead frame 32 and the third lead frame 31 may also be spaced apart by the above-described interval 'a'.

3 is a cross-sectional view of another embodiment of a light emitting device package.

3 is similar to the embodiment shown in FIG. 1, but the lens 80 is disposed on the resin layer 70. The lens 80 may be made of a light transmissive material such as silicon or epoxy, and the edge of the lens may be fixed on the sidewall of the circuit board 110 or on the circuit board 110.

In addition, the lens 80 may be recessed in the center portion as shown in addition to the hemispherical or parabolic surface to adjust the orientation angle of the light emitting device package.

4 to 10 is a view showing an embodiment of a manufacturing method of the light emitting device package of FIG.

First, as shown in FIG. 4, the insulating layer 10 is prepared and punched. Since the insulating layer 10 is made of an insulating material such as polyimide and may serve as a supporting layer of the light emitting device package, the insulating layer 10 should be provided with sufficient thickness and width. When the punching process is completed, an open region is formed in the center of the insulating layer 10.

Since the open area of the insulating layer 10 is for dissipating heat from the light emitting device, the open area of the insulating layer 10 may be formed in a predetermined area.

As shown in FIG. 5, the lead frame 30 is bonded to the insulating layer 10 on which the open area is formed through the adhesive layer 20. The insulating layer 10 may be an insulating material such as polyimide, and the adhesive layer 20 may also be an insulating material.

As shown in FIG. 6, an isolation process of the lead frame 30 is performed to form a third lead frame (heat radiating layer 31), a first lead frame 32, and a second lead frame 33. To separate.

At this time, each of the lead frames 31 to 33 may be electrically separated from each other. Since the third lead frame 31 contacts the light emitting device 50, one of the first and second lead frames 32 and 33 may be used. It must be electrically isolated from at least one.

After the separation process, the open region in the insulating layer 10 and the third lead frame 31 correspond to each other, but the widths thereof are different from each other.

As shown in FIG. 7, the reflective layers 40 are formed on the respective lead frames 31 to 33. The reflective layer 40 may be formed of silver (Ag), aluminum (Al), or the like having excellent light reflectance. In addition, although the reflective layer 40 is not formed at the ends of the first lead frame 32 and the second lead frame 33 in the drawing, the circuit board is in contact with the first and second lead frames 32 and 33. When the reflective layer 40 is a conductive material, the circuit board may be connected to the first and second lead frames 32 and 33 through the reflective layer 40.

As illustrated in FIG. 8, the light emitting device 50 is disposed on the third lead frame 31, and the light emitting device 50 is electrically connected to the first and second lead frames 32 and 33. In the present exemplary embodiment, since the reflective layer 40 is a conductive material, the reflective layer 40 and the light emitting device 50 are bonded to the wire 60, but when the reflective layer 40 is a non-conductive material, the light emitting device 50 is removed. The wire bonding can be carried out directly to the first and second conductive layers 32 and 33.

9, the circuit board 110 is connected to the first and second lead frames 32 and 33, respectively. In this case, the circuit board 110 may be connected to the first and second lead frames 32 and 33 through a conductive adhesive (not shown).

In FIG. 9, it may be assumed that a cavity is formed around the light emitting device 50, and the sidewall of the cavity becomes the side surface of the circuit board 110. In addition, a reflective layer (not shown) may be formed on the side surface of the circuit board 110 forming the sidewalls of the cavity.

In addition, as shown in FIG. 10, the resin layer 70 is injected into the cavity described above. The resin layer 70 may include a phosphor 75 to change wavelengths of light emitted from the light emitting device 50. have.

The resin layer 70 may be supplied and cured to surround the light emitting device 50 and the wire 60 electrically connecting the light emitting device 50 and the first and second lead frames 32 and 33.

11 is a view showing heat emission and light emission of a light emitting device package according to a comparative example.

In the conventional light emitting device package according to the comparison, the light emitting device 270 is disposed on the package body 260, and the light emitting device 270 is covered with the resin layer 280. A current is supplied to the light emitting device 270 through the first and second lead frames 221 and 222, and a current is supplied to the first and second lead frames 221 and 222 through a circuit board. The heat dissipation layer 250, the buffer layer 240, the insulating layer 230, and the conductive layer 210 may be formed.

In FIG. 11, the arrow indicated by the upward direction of the light emitting device 270 is the traveling direction of the light L, and the arrow indicated by the downward direction of the light emitting device 270 is the emission direction of the heat H.

In the comparative example, the light emitting device package having no cavity has a wide light directing angle and can reduce cost, but is not suitable for applications requiring narrow directivity and high brightness such as edge type backlight.

In addition, PCB, MCPCB, FR4 and F-PCB can be used as the circuit board, FR4 or F-PCB is not good heat dissipation characteristics, MCPCB is relatively good heat dissipation characteristics, but the cost increases.

12 is a view schematically showing heat emission and light emission of the light emitting device package according to the embodiment.

In the present exemplary embodiment 100, the light emitting device 50 is connected to the lead frame 30 through the adhesive layer 20, and the circuit board 110 is disposed on the side of the light emitting device 50 on the lead frame 30. Is placed. The heat dissipation member 120 is in contact with the lead frame 30 through the heat transfer layer 130, and the heat dissipation member may be a bracket or a support substrate of a lighting device or a backlight unit.

In the light emitting device package according to the embodiment, heat (H) generated from the light emitting device may be directly emitted to the outside from the lead frame without passing through the circuit board, and heat of the circuit board may also be directly discharged to the outside.

In addition, since the light L emitted from the light emitting device 50 may be reflected from the side of the circuit board 110 on the side of the cavity, the direction angle may be adjusted. In addition, since the heat dissipation characteristics of the circuit board are excellent, MCPCB may not be used, thereby reducing the cost of materials.

Hereinafter, an illumination device and a backlight unit will be described as an embodiment of a lighting system in which the above-described light emitting device package is disposed.

13 is an exploded perspective view of an embodiment of a lighting device including a light emitting device package according to the embodiments.

The lighting apparatus according to the embodiment includes a light source 600 for projecting light, a housing 400 in which the light source 600 is embedded, a heat dissipation part 500 for dissipating heat from the light source 600, and the light source 600. And a holder 700 for coupling the heat dissipation part 500 to the housing 400.

The housing 400 includes a socket coupling part 410 coupled to an electric socket and a body part 420 connected to the socket coupling part 410 and having a light source 600 embedded therein. One air flow port 430 may be formed in the body portion 420.

A plurality of air flow port 430 is provided on the body portion 420 of the housing 400, wherein the air flow port 430 is composed of one air flow port, or a plurality of flow ports as shown in the radial arrangement Various other arrangements are also possible.

The light source 600 includes a plurality of light emitting device packages 650 on the circuit board 610. Here, the circuit board 610 may be inserted into the opening of the housing 400, and may be made of a material having a high thermal conductivity to transmit heat to the heat dissipating unit 500, as described later.

A holder 700 is provided below the light source, and the holder 700 may include a frame and another air flow port. In addition, although not shown, an optical member may be provided under the light source 100 to diffuse, scatter, or converge light projected from the light emitting device package 150 of the light source 100.

The above-described lighting apparatus has improved heat dissipation, reduced material cost, and excellent light directing angle.

14 illustrates a backlight including a light emitting device package according to embodiments.

As shown, the display device 800 according to the present exemplary embodiment is disposed in front of the light source modules 830 and 835, the reflector 820 on the bottom cover 810, and the reflector 820. The light guide plate 840 for guiding light emitted from the front of the display device, the first prism sheet 850 and the second prism sheet 860 disposed in front of the light guide plate 840, and the second prism sheet ( And a color filter 880 disposed in front of the panel 870 disposed in front of the panel 870.

The light source module includes a light emitting device package 835 on the circuit board 830. Here, the PCB 830 may be used as the circuit board 830, and the light emitting device package 835 is as described above.

The bottom cover 810 may accommodate components in the display device 800. The reflective plate 820 may be provided as a separate component as shown in the drawing, or may be disposed on the rear surface of the light guide plate 840, or The bottom cover 810 may be provided in the form of a coating with a highly reflective material.

Here, the reflection plate 820 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and polyethylene terephthalate (PET) can be used.

The light guide plate 830 scatters the light emitted from the light emitting device package module so that the light is uniformly distributed over the entire area of the screen of the liquid crystal display. Accordingly, the light guide plate 830 is made of a material having a good refractive index and transmittance. The light guide plate 830 may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), or polyethylene (PE). The light guide plate 83 may be omitted from the backlight unit so that air acts as an optical waveguide.

In addition, the light guide plate 840 may be omitted, and may be an air guide method in which the light reflected from the reflector 820 proceeds straight to the panel direction.

The first prism sheet 850 is formed of a translucent and elastic polymer material on one surface of the support film, and the polymer may have a prism layer in which a plurality of three-dimensional structures are repeatedly formed. Here, the plurality of patterns may be provided in the stripe type and the valley repeatedly as shown.

In the second prism sheet 860, the direction of the floor and the valley of one surface of the support film may be perpendicular to the direction of the floor and the valley of one surface of the support film in the first prism sheet 850. This is to evenly distribute the light transmitted from the light source module and the reflective sheet in all directions of the panel 870.

Although not shown, a protective sheet may be provided on each prism sheet, and a protective layer including light diffusing particles and a binder may be provided on both surfaces of the support film.

In addition, the prism layer is made of a polymer material selected from the group consisting of polyurethane, styrene butadiene copolymer, polyacrylate, polymethacrylate, polymethylmethacrylate, polyethylene terephthalate elastomer, polyisoprene, polysilicon Can be.

Although not shown, a diffusion sheet may be disposed between the light guide plate 840 and the first prism sheet 850. The diffusion sheet may be made of polyester and polycarbonate-based materials, and may maximize the light projection angle through refraction and scattering of light incident from the backlight unit.

The diffusion sheet includes a support layer including a light diffusing agent, a first layer and a second layer formed on a light exiting surface (first prism sheet direction) and a light incident surface (reflective sheet direction) and not including a light diffusing agent. It may include.

The support layer is 0.1 to 10 parts by weight of a siloxane light diffusing agent having an average particle diameter of 1 to 10 micrometers with respect to 100 parts by weight of a resin in which a methacrylic acid-styrene copolymer and a methyl methacrylate methyl-styrene copolymer are mixed; 0.1 to 10 parts by weight of an acrylic light diffusing agent having an average particle diameter of 1 to 10 micrometers may be included.

The first layer and the second layer may be included as 0.01 to 1 part by weight of the ultraviolet absorber and 0.001 to 10 parts by weight of the antistatic agent based on 100 parts by weight of the methyl methacrylate-styrene copolymer resin.

The thickness of the support layer in the diffusion sheet is 100 ~ 10000 micrometers, the thickness of each layer may be 10 ~ 1000 micrometers.

In the present embodiment, the diffusion sheet, the first prism sheet 850 and the second prism sheet 860 form an optical sheet, and the optical sheet is made of another combination, for example, a micro lens array or a diffusion sheet and a micro Combination of a lens array or a combination of one prism sheet and a micro lens array.

The liquid crystal display panel (Liquid Crystal Display) may be disposed on the panel 870, in addition to the liquid crystal display panel 860 may be provided with other types of display devices that require a light source.

The panel 870 is a state in which the liquid crystal is located between the glass body and the polarizing plate is placed on both glass bodies in order to use the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display panel used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

The front surface of the panel 870 is provided with a color filter 880 to transmit the light projected from the panel 870, only the red, green and blue light for each pixel can represent an image.

The above-described lighting apparatus has improved heat dissipation, reduced material cost, and excellent light directing angle.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

10, 230: insulation layer 20, 90: adhesive layer
30, 31-33, 221, 222: lead frame
40: reflection layer 50, 270: light emitting element
60: wire 70, 280: resin layer
75 phosphor 80 lens
100: light emitting device package 110: a circuit board
120: heat dissipation member 130: heat transfer layer
210: conductive layer 240: buffer layer
250: heat release layer 260: package body
400: housing
500: radiator 600: light source
700: holder 800: display device
810: bottom cover 820: reflector
830: circuit board module 840: light guide plate
850, 860: first and second prism sheet 870: panel
880 color filter

Claims (17)

Insulating layer;
A pair of lead frames provided on the insulating layer and electrically separated from each other;
A light emitting element electrically connected to the pair of lead frames, the light emitting element being disposed in a direction opposite to the insulating layer with respect to the pair of lead frames; And
And a pair of circuit boards disposed in a direction opposite to the insulating layer with respect to the pair of lead frames, and electrically connected to the pair of lead frames, respectively. The method of claim 1,
The insulating layer is a light emitting device package made of polyimide. The method of claim 1,
The light emitting device package further comprises a heat dissipation member in contact with the insulating layer. The method of claim 1,
The insulating layer has a light emitting device package having at least one open area. The method of claim 4, wherein
And a heat dissipation member contacting the insulating layer, wherein a thermal interface material is disposed in the open area, and the insulating layer and the heat dissipation member are in contact with the thermal contact material. The method of claim 5, wherein
The light emitting device is a light emitting device package disposed on the open area. The method according to claim 6,
And a third lead frame disposed between the pair of lead frames and electrically separated from the pair of lead frames, wherein the light emitting device is disposed on the third lead frame. The method of claim 7, wherein
And the third lead frame is separated from the pair of lead frames by at least 50 micrometers, respectively. The method of claim 8,
And the third lead frame is in contact with the thermal contact material. The method of claim 1,
The light emitting device package further comprises a resin layer covering the light emitting device, wherein the edge of the resin layer is formed on the side of the circuit board. 11. The method of claim 10,
The height of the edge of the resin layer is a light emitting device package lower than the height of the circuit board. 11. The method of claim 10,
The light emitting device is wire-bonded with the pair of lead frames, and the resin layer covers the wire. Insulating layer;
A heat dissipation layer disposed on the insulating layer;
A light emitting element on the heat dissipation layer;
First and second lead frames spaced apart from the heat dissipation layer and electrically connected to the light emitting devices, respectively; And
And a pair of circuit boards disposed on the first lead frame and the second lead frame, respectively, and electrically connected to the first lead frame and the second lead frame, respectively. The method of claim 13,
The heat dissipation layer is a light emitting device package made of the same material as the first lead frame and the second lead frame. 15. The method of claim 14,
The insulating layer has at least one open area, the open area corresponding to the heat dissipation layer. The method of claim 15,
And a heat dissipation member contacting the insulating layer, wherein a thermal interface material is disposed in the open area, and the insulating layer and the heat dissipation member are in contact with the thermal contact material. 17. An illumination system comprising the light emitting device package of any one of claims 1-16.

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