KR101221920B1 - Light emitting device package and back-light unit using the same - Google Patents

Abstract

The present invention relates to a light emitting device, and more particularly, to a light emitting device package capable of improving light efficiency and a backlight using the same. This invention, the package body of a transparent material having a first side and a second side; At least a portion of the mounting body located in the package body and facing the first surface; A lead frame including at least a portion of the package body and having a first terminal and a second terminal extending outwardly in the first surface direction; And a light emitting device mounted on the mounting portion and electrically connected to the first terminal and the second terminal.

Description

Light emitting device package and back light unit using the same {Light emitting device package and back-light unit using the same}

The present invention relates to a light emitting device, and more particularly, to a light emitting device package capable of improving light efficiency and a backlight using the same.

In general, among displays, liquid crystal displays (LCDs) are used in various devices ranging from televisions, notebook computers, desktop monitors, and mobile phones.

Since the LCD does not emit light by itself, a light emitting device capable of illuminating a liquid crystal panel is required to display image information.

Since the light emitting device of the LCD is coupled to the rear surface of the liquid crystal panel, it is called a backlight unit. The backlight unit is a device that provides a light source to the liquid crystal panel by forming a uniform surface light source.

The light emitting diode (LED) has a structure in which an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer are stacked on a substrate, and electrodes are formed on the p-type semiconductor and the n-type semiconductor layer. The principle of generating light of such a light emitting diode is that light is generated in the light emitting layer and extracted to the outside by recombination of holes and electrons injected from each semiconductor layer.

Such a light emitting diode may be used as a light source of a back-lihgt unit (BLU) by forming a light emitting diode package.

SUMMARY OF THE INVENTION The present invention provides a light emitting device package and a backlight using the light emitting device package which can increase the brightness by minimizing lost light and reduce power consumption by allowing light to be effectively emitted without being reabsorbed in the light emitting device package. We want to provide a unit.

As a first aspect for achieving the above technical problem, the present invention, the package body of the transparent material having a first surface and a second surface; At least a portion of the mounting body located in the package body and facing the first surface; A lead frame including at least a portion of the package body and having a first terminal and a second terminal extending outwardly in the first surface direction; And a light emitting device mounted on the mounting portion and electrically connected to the first terminal and the second terminal.

As a second aspect for achieving the above technical problem, the present invention includes a plurality of light sources including a package body of a transparent material, at least two light emitting device packages for emitting light in different directions; A circuit board having a reflective layer for reflecting light emitted from the light source; And a diffusion part disposed on the light emitting device package.

The present invention has the following effects.

First, the light directing angle is set by the lens provided in the package body or the angle to the circuit board of the package body, and by combining two or more light emitting device packages made of a transparent material as a light source to increase the light efficiency. Can be.

In addition, the shape of the lead frame can be optimized to provide an effective heat dissipation and reflection structure, resulting in lower power consumption and maximum reliability and light efficiency.

1 is a perspective view illustrating an example of a light emitting device package.
2 is a perspective view showing another example of a light emitting device package.
3 is a side view of FIG. 2.
4 is an enlarged view illustrating a heat dissipation structure of a first electrode.
5 is a cross-sectional view showing a light source.
6 is a cross-sectional view showing another example of the light source.
7 is a plan view illustrating an example of a light source.
8 is a plan view illustrating another example of the light source.
9 is a schematic view showing a first example of a backlight unit.
10 is a schematic diagram illustrating a second example of the backlight unit.
11 is a schematic diagram illustrating a third example of the backlight unit.
12 is a schematic diagram illustrating a fourth example of the backlight unit.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers, and / or regions, such elements, components, regions, layers, and / or regions It will be understood that it should not be limited by these terms.

As shown in FIG. 1, the light emitting device package 100 includes a package body 10 made of a transparent material, a mounting unit 20, a lead frame 30, and a light emitting device 40 mounted on the mounting unit 20. It includes.

The package body 10 includes a lower surface of the first surface 11 and an upper surface of the second surface 12, and the mounting portion 20 is located inside the package body 10 and faces the first surface 11. It is configured to. Therefore, the light emitting device 40 mounted on the mounting portion 20 emits light toward the first surface 11. In some cases, at least a portion of the mounting portion 20 may be exposed to the outside of the package body 10.

The lead frame 30 may include a first terminal 31 and a second terminal 32, and the first terminal 31 may be connected to the mounting unit 20. As shown, at least a portion of the first terminal 31 and the second terminal 32 is positioned inside the package body 10 and extends outside the package body 10 toward the first surface 11. do.

That is, the first terminal 31 and the second terminal 32 extend outside the package body 10 through the first surface 11, but through the other surface (for example, the side of the package body). Even if it extends to the outside may be configured to be bent in the first surface 11 direction.

The light emitting device 40 mounted on the mounting unit 20 may use a light emitting diode, and two electrodes of the light emitting diode are electrically connected to the first terminal 31 and the second terminal 32, respectively.

The material of the package body 10 may be made of an insulating transparent material. For example, transparent ceramics such as silicon, epoxy, white polyphthalamide (white PPA), glass, and silicon oxide (SiO ₂ ) may be used. Can be used.

In addition, the lens 50 may be further provided on the first surface 11 of the package body 10 facing the main light emitting surface of the light emitting device 40, and thus the directivity of light emitted from the light emitting device 40 and Properties can be improved. As for the lens 50, an aspherical lens may be used.

At this time, at least one side of the lens 50 and the package body 10 may include a phosphor, it is possible to convert the wavelength of the light emitted from the light emitting device (40). For example, blue light emitted from the light emitting device 40 may be converted into white light.

In addition, a separate phosphor layer (not shown) may be located inside the package body 10 or in proximity to or in contact with the light emitting device 40.

As shown in FIG. 2, the first terminal 31 of the lead frame 30 may have a shorter length than the second terminal 32. Then, as shown in FIG. 3, when the light emitting device package 100 is installed on a circuit board, the package body 10 has an inclined direction, and the light emitted from the light emitting device 40 is reflected to spread in the lateral direction. Can be.

As such, the package body 10 may have an inclined direction, and may form an angle of 0 ° to 45 ° with respect to a plane in which the first terminal 31 and the second terminal 32 contact each other.

In addition, the first terminal 31 may be provided with a reflective surface, so that the light emitted from the light emitting device 40 can be spread more effectively in the lateral direction. To this end, a silver (Ag) film may be coated on the outer surface of the first terminal 31.

As shown in FIG. 2, the first terminal 31 may be electrically or thermally connected to the mounting unit 20. In the case of being thermally connected, the first terminal 31 may have a larger surface area than the second terminal 32 so that the heat generated from the light emitting device 40 can be effectively released.

In addition, in order to maximize the heat dissipation effect, as shown in FIG. 4, the heat dissipation structure 31a may be formed in the first terminal 31. The heat dissipation structure 31a may use a heat exchange structure such as a fin as a structure to increase the surface area.

As shown in FIG. 5, the light emitting device packages 101 and 102 may be used as the light source 400 by installing two or more packages on or in contact with each other on the circuit board 200.

On the circuit board 200 where the light emitting device packages 101 and 102 are installed, a reflective layer 210 may be provided to reflect the light emitted from the light emitting device, and the reflective layer 210 may include the light emitting device package 101. , 102 may be selectively provided where the location is located, or may be provided throughout the circuit board 200.

As the reflective layer 210, a photo sensitive resist (PSR) may be used. In the case of using the photosensitive resist, the reflective layer 210 may be formed on the entire circuit board, and the reflective layer 210 may be positioned only in a desired portion through exposure.

Such photosensitive resists can exhibit sufficient reflectance because the reflectance is 90% or more (about 92 to 93%). In some cases, a reflective sheet containing a metal may be used as the reflective layer 210. As the reflective sheet, a silver reflective sheet in which holes are perforated may be used.

In FIG. 5, two light emitting device packages 101 and 102 are installed in contact with each other, and the inclined direction of the package body 10 is symmetrical with respect to the contact surfaces of the two packages 101 and 102. In order to be installed, the directing angles of the light emitted from the light emitting element 40 may be directed in opposite directions to each other.

That is, the light emitting device package 101 on the left side can achieve a directing angle of the first angle θ ₁ with respect to the installation surface, and the light emitting device package 102 on the right side has a second direction opposite to the installation surface. It can be installed to achieve a direction angle of the angle θ ₂ . Light emitted with such a directivity angle may be reflected by the reflective layer 210 and effectively spread uniformly upwardly through the lateral or package body 10.

In this case, the first angle θ ₁ and the second angle θ ₂ may form the same angle opposite to each other, and the angle may have a range of 0 ° to 45 °, but considering light uniformity. If so, the range of 10 ° to 30 ° may be more advantageous.

On the other hand, the circuit board 200 is provided with a circuit line (not shown) to enable the light emitting device packages 101 and 102 to be driven by the power source.

A heat dissipation structure may be provided at a portion of the circuit board 200 connected to the lead frame 30. For example, a heat dissipation hole 201 to which the first electrode 31 is connected may be configured. That is, heat may be directly emitted through the heat dissipation hole 201.

In addition, the heat dissipation hole 201 may be provided with a heat transfer medium 220 that is thermally connected to the first electrode 31, so that heat emitted from the light emitting device 40 is transferred through the first electrode 31. It may be possible to be released through the heat transfer medium 220.

At this time, the heat transfer medium 220 is provided with a heat release pad 221, it may be provided with an external contact so that the heat transferred in this way can be effectively discharged to the outside.

6 shows another example of a state in which the light emitting device package 110 as a light source is installed on the circuit board 200.

That is, the light emitting device package 110 includes the first electrode 31 and the second electrode 32 having the same length, so that the package body 10 is mounted on the circuit board 200 without tilting, but has a directing angle. An example in which an asymmetric lens 51 having an angle inclined in this side direction is provided.

The other part, for example, the directivity of the light emitted from the light emitting element 40 can be applied in the same manner as described above.

As such, the plan view seen from above in the case of the light source 400 including the two light emitting device packages 101 and 102 is illustrated in FIG. 7. That is, the light emitted from the light emitting device is emitted in the lateral direction and the downward direction to be reflected in the reflective layer and spread evenly.

Meanwhile, as shown in FIG. 8, the light source 400 may be configured using four light emitting device packages 120 having light directing in the corner direction of the package body 10.

As such, four light emitting device packages 120 may form a rectangular light source 400, and may form a light source in which light is emitted in four corners of the quadrangle.

As shown in FIG. 9, the diffusion part 300 is positioned above the light source 400 so that the light emitted from the light source 400 may be diffused and uniformly mixed. As such, when light is uniformly mixed and emitted, it may be used as a backlight unit of a display device.

The diffusion unit 300 may include a diffuser plate 310 positioned above the light source 400, and the prism 320 may be positioned on the diffuser plate 310.

The prism 320 may include two prisms disposed at right angles to each other. The prism 320 may include a vertical prism 321 disposed on the diffuser plate 310 and a prism 321 disposed on the vertical prism 321. A horizontal prism (s-prizm) 322.

In addition, a uniform protective film may be further disposed on the prism 320, and an example of the uniform protective film may be a diffuser sheet 330. In some cases, a dual brightness enhancement film (DBEF) may be provided instead of the diffuser sheet 330.

This brightness enhancement film allows more light to be used by passing the first component of the polarized light and reflecting the second component in the vertical direction. For example, by passing the p-wave and reflecting the s-wave, light of the reflected s-wave can be reflected by the circuit board 200 or the reflective layer 210 and emitted again.

As shown in FIG. 10, the light guide plate 340 may be used as the diffusion part 300. The light guide plate 340 may be formed with a hole 341 where the light source 400 is located.

Therefore, the light source 400, the circuit board 200, and the light guide plate 340 may be easily coupled, and light in the horizontal and vertical directions may be uniformly mixed in the light guide plate 340.

In addition, FIG. 11 illustrates an example in which the light guide plate 350 coated on the circuit board 200 together with the light source 400 is provided as the diffusion part 300. The light guide plate 350 may be a resin layer coated with a thickness covering the light source 400 on the circuit board 200.

Meanwhile, FIG. 12 illustrates an example in which a plurality of light guide plate modules 360 covering each light source 400 are provided as the diffusion part 300. The light guide plate module 360 is provided with a groove 361 in which the light source 400 can be positioned, so that each light guide plate module 360 may be disposed on each light source 400.

In the above-described embodiments, items specific to each embodiment may be applied to other embodiments. For example, the heat dissipation hole 201 and the heat transfer medium 220 illustrated in FIG. 5 may be applied to other embodiments, and the package structure illustrated in FIG. 6 may be applied to embodiments of other backlight units. to be.

According to the above embodiments, the light directing angle is set by the lens provided in the package body or the angle to the circuit board of the package body, by combining two or more light emitting device packages made of a transparent material as a light source Can increase the light efficiency.

In addition, the shape of the lead frame can be optimized to provide an effective heat dissipation and reflection structure, resulting in lower power consumption and maximum reliability and light efficiency.

Conventional backlight units lose significant portions while light emitted from the light source exits the backlight unit. Moreover, the polarizers on the front and back of the LCD panel are absorbing, so they absorb 50% of the light directed to the panel. Thus, in the actual display, the viewer sees less than 10% of the light from the light source.

However, using the light source 400 and the structure optimized for the light source 400 described above can greatly improve the light utilization efficiency, which can greatly reduce the power consumption.

10: package body 20: mounting portion
30: lead frame 40: light emitting element
50 lens 100 light emitting device package
200: circuit board 300: diffusion part
400: light source

Claims (15)

A package body of transparent material having a first side and a second side;
At least a portion of the mounting body located in the package body and facing the first surface;
A lead frame including at least a portion of the package body and having a first terminal and a second terminal extending outwardly in the first surface direction; And
And a light emitting device mounted on the mounting portion and electrically connected to the first terminal and the second terminal. The light emitting device package of claim 1, further comprising a lens positioned on a first surface of the light emitting device. The light emitting device package of claim 2, wherein at least one side of the lens and the package body includes a phosphor or a phosphor layer on the light emitting device. The light emitting device package according to claim 1, wherein the first terminal has a shorter length than the second terminal. The light emitting device package of claim 4, wherein the first terminal has a larger surface area than the second terminal. The light emitting device package according to claim 4, wherein the first terminal is provided with a reflective surface. The light emitting device package according to claim 4, wherein the first terminal comprises a heat dissipation structure. 5. The light emitting device package of claim 4, wherein the package body forms an angle of 0 ° to 45 ° with respect to a plane in which the first terminal and the second terminal contact each other. A plurality of light sources including a package body made of a transparent material and including at least two light emitting device packages emitting light in different directions;
A circuit board having a reflective layer for reflecting light emitted from the light source; And
And a diffusion unit disposed on the light emitting device package. The backlight unit of claim 9, wherein the light directing angle of the light emitting device package is in an angle of 45 ° to 90 ° with respect to a plane of the circuit board. The backlight unit of claim 9, wherein the two or more light emitting device packages emit light in directions opposite to each other. The method of claim 9, wherein the diffusion unit,
Diffuser plates; And
And a prism positioned on the diffuser plate. The backlight unit of claim 12, wherein the diffusion unit further comprises a uniformity protective film or a brightness reinforcing film positioned on the prism. 10. The backlight unit of claim 9, wherein the light directing angle of the light emitting device package is set by a lens provided in the package body or an angle with respect to a circuit board of the package body. The backlight unit of claim 9, wherein the diffusion part is a light guide plate.

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