KR102617482B1 - Led package and direct type backlight unit comprising the same - Google Patents

Abstract

The present invention relates to a light emitting device package capable of implementing a planar light source, comprising: a thin film substrate on which a first subsubstrate and a second subsubstrate are formed; a light emitting device including a first electrode pad located on the first sub-substrate and a second electrode pad located on the second sub-substrate; a molding member surrounding the upper surface of the thin film substrate and the side and upper surfaces of the light emitting device and transmitting light emitted from the light emitting device; and a reflective member formed on an upper portion of the molding member to reflect light emitted from the light emitting device, wherein the reflective member changes top light of the light emitting device into side light, and a proportion of the side light is determined by the upper portion of the molding member. It is characterized by being larger than the specific gravity of light.

Description

Light emitting device package and direct type backlight unit including the same {LED PACKAGE AND DIRECT TYPE BACKLIGHT UNIT COMPRISING THE SAME}

The present invention relates to a light emitting device package and a backlight unit including the same, and more specifically, to a light emitting device package capable of implementing a surface light source and a backlight unit including the same.

A light emitting device (LED) is a type of semiconductor device that converts electrical energy into light energy. Light-emitting devices have the advantages of low power consumption, semi-permanent lifespan, fast response speed, safety, and environmental friendliness compared to existing light sources such as fluorescent lamps and incandescent lamps.

Accordingly, much research is being conducted to replace existing light sources with light-emitting devices, and the use of light-emitting devices as a light source for lighting devices such as various lamps, liquid crystal displays, electronic signs, and street lights used indoors and outdoors is increasing. .

Meanwhile, since the liquid crystal display panel of the liquid crystal display device is a light-receiving element that cannot emit light on its own, a backlight unit is needed to irradiate light to the panel from the bottom of the liquid crystal display panel. This backlight unit consists of an LED lamp, a light guide plate, a reflective sheet, and an optical sheet.

Typically, LED lamps used in backlight units provide white light to the liquid crystal display panel using a light-emitting element and a color conversion material. Depending on where the LED lamp provides light to the liquid crystal display panel, backlight units are divided into edge type and direct type. The edge type is a method that provides light from the side by arranging LED elements on the side of the liquid crystal display panel, and the direct type is a method that provides light from the back by arranging LED elements on the back of the liquid crystal display panel.

Since the edge type provides light only from one side of the LCD panel, the larger the LCD panel, the more the problem of light being concentrated on one side occurs. Therefore, with the trend toward larger LCDs, it is expected that the direct type will be preferred over the edge type in the future, and accordingly, technology development for the direct type is actively progressing.

Light emitting devices that can be used in a backlight unit largely include vertical type light emitting devices, horizontal type light emitting devices, and flip-chip type light emitting devices. The vertical and horizontal light emitting devices are electrically connected through upper or lower wire bonding, so miniaturization is limited, additional wires are required, and light extraction efficiency is reduced by the wires. . Therefore, recently, flip-chip type light emitting devices that do not require wire bonding and have high light extraction efficiency are mainly used in backlight units.

Flip-chip type light emitting devices are implemented in the form of a chip scale package (CSP, chip scale package). These CSPs are manufactured by applying a light-transmitting material to surround the side and top surfaces of the flip chip type light emitting device, and are a package as small as the chip size. can be implemented. The general ‘CSP’ structure is a structure in which white silicon is formed to surround the sides of a light-transmissive material to improve the amount of light emitted from the top of the flip-chip type light emitting device.

However, in this general CSP structure, most of the light is emitted toward the top of the flip chip type light emitting device, so a secondary optical lens is needed to satisfy the wide light beam angle required by the direct backlight unit. However, the volume occupied by the secondary optical lens increases the thickness of the backlight unit, making it difficult to slim the display panel. Additionally, there is a problem that raw material and processing costs increase due to the use of secondary optical lenses.

The present invention aims to solve the above-mentioned problems and other problems. Another purpose is to provide a light emitting device package that can implement a planar light source by reflecting light radiating upward from the light emitting device in the horizontal direction through an aspherical boundary surface where a molding member and a reflection member meet, and a method of manufacturing the same.

Another purpose is to place a reflective sheet assembly of a predetermined shape on a circuit board on which a plurality of light emitting device packages are mounted, thereby improving the light uniformity of the surface light source emitted from the light emitting device packages, and a method of manufacturing the same. In providing.

According to one aspect of the present invention to achieve the above or other objects, there is provided a thin film substrate on which a first sub-substrate and a second sub-substrate are formed; a light emitting device including a first electrode pad located on the first sub-substrate and a second electrode pad located on the second sub-substrate; a molding member surrounding the upper surface of the thin film substrate and the side and upper surfaces of the light emitting device and transmitting light emitted from the light emitting device; and a reflective member formed on an upper portion of the molding member to reflect light emitted from the light emitting device, wherein the reflective member changes top light of the light emitting device into side light, and a proportion of the side light is determined by the upper portion of the molding member. Provided is a light emitting device package characterized in that the specific gravity of light is greater than that of light.

According to another aspect of the invention, arranging a plurality of thin film substrates on an adhesive member attached to the upper surface of a support substrate; Mounting a plurality of light emitting devices on top of the plurality of thin film substrates; forming a molding member on the support substrate, the thin film substrates, and the light emitting elements, and forming a reflective member on the molding member; and removing an adhesive member and a support substrate attached to the lower surfaces of the molding member and the thin film substrates, wherein the forming step includes forming an aspherical interface between the molding member and the reflective member using an injection molding method. A method of manufacturing a light emitting device package is provided.

According to another aspect of the present invention, a circuit board; a plurality of light emitting device packages mounted on the circuit board; a reflective sheet assembly formed on the circuit board and made of a plurality of reflective sheet units; and a diffusion sheet disposed on an upper portion of the reflective sheet assembly, wherein the reflective sheet units are formed of holes surrounding the light emitting device package and a plurality of inclined surfaces extending from the holes and having a radius of curvature, the inclined surfaces being A backlight unit is provided that changes side light of the light emitting device packages into top light.

The effects of a light emitting device package and a backlight unit including the same according to embodiments of the present invention will be described as follows.

According to at least one of the embodiments of the present invention, by manufacturing a light emitting device package in which an aspherical interface is formed between a molding member and a reflective member, light radiating upward from the light emitting device is transmitted into an aspherical shape where the molding member and the reflective member meet. It has the advantage of being able to easily implement a planar light source by reflecting it in the horizontal direction through the boundary surface.

In addition, according to at least one of the embodiments of the present invention, by manufacturing a backlight unit including a reflective sheet assembly disposed on an upper portion of the circuit board, the surface light source emitted from the plurality of light emitting device packages mounted on the circuit board There is an advantage in that light uniformity can be improved.

However, the effects that can be achieved by the light emitting device package and the backlight unit including the same according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned can be found from the description below to which the present invention belongs. It will be clearly understandable to those with ordinary knowledge in the technical field.

1A is a perspective view of a light emitting device package according to a first embodiment of the present invention;
1B is a cross-sectional view of a light emitting device package according to a first embodiment of the present invention;
Figure 1C is an exploded perspective view of a light emitting device package according to a first embodiment of the present invention;
Figure 2a is a perspective view of a light emitting device package according to a second embodiment of the present invention;
Figure 2b is a cross-sectional view of a light emitting device package according to a second embodiment of the present invention;
Figure 2c is an exploded perspective view of a light emitting device package according to a second embodiment of the present invention;
Figure 3a is a perspective view of a light emitting device package according to a third embodiment of the present invention;
Figure 3b is a cross-sectional view of a light emitting device package according to a third embodiment of the present invention;
Figure 3c is an exploded perspective view of a light emitting device package according to a third embodiment of the present invention;
4A to 4F are diagrams illustrating a method of manufacturing a light emitting device package according to the present invention;
5A is a cross-sectional view of a backlight unit according to an embodiment of the present invention;
Figure 5b is an exploded perspective view of a backlight unit according to an embodiment of the present invention;
Figure 6 is a diagram showing a circuit board coated with a diffuse reflection removal material in the peripheral area of a light emitting device package;
Figure 7 is a perspective view showing the shape of a reflective sheet assembly according to an embodiment of the present invention.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. Hereinafter, in the description of embodiments according to the present invention, each layer (film), region, pattern or structure is “on” or “below” the substrate, each layer (film), region, pad or pattern. In the case where it is described as being formed in “/under,” “on” and “under” mean “directly” or “indirectly through another layer.” “Includes everything that is formed. Additionally, the standards for top/top or bottom/bottom of each floor are explained based on the drawing. In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Additionally, the size of each component does not entirely reflect the actual size.

Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

The present invention proposes a light emitting device package and a manufacturing method thereof that can implement a planar light source by reflecting light radiating upward from a light emitting device in the horizontal direction through an aspherical boundary surface where a molding member and a reflection member meet. In addition, the present invention relates to a backlight unit capable of improving light uniformity of a surface light source emitted from the light emitting device packages by disposing a reflective sheet assembly of a predetermined shape on a circuit board on which a plurality of light emitting device packages are mounted, and manufacturing the same. suggest a method

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

FIG. 1A is a perspective view of a light-emitting device package according to a first embodiment of the present invention, FIG. 1B is a cross-sectional view of a light-emitting device package according to a first embodiment of the present invention, and FIG. 1C is a perspective view of a light-emitting device package according to a first embodiment of the present invention. This is an exploded perspective view of the light emitting device package.

1A to 1C, the light emitting device package 100 according to the first embodiment of the present invention includes a thin film substrate 110, a light emitting device 120 disposed on the thin film substrate 110, and the light emitting device It may include a molding member 130 surrounding the 120, a reflective layer 140 disposed on the molding member, and a reflective member 150 disposed on the reflective layer 140. Here, the reflective layer 140 may be configured to be omitted depending on the embodiment.

The light emitting device package 100 can implement a planar light source by reflecting light radiating upward from the light emitting device 120 in the horizontal direction through an aspherical boundary surface where the molding member 130 and the reflecting member 150 meet. there is. This light emitting device package 100 may be formed in a cube or rectangular parallelepiped shape, but is not necessarily limited thereto.

The thin film substrate 110 is electrically connected to the light emitting device 120 and may serve to mediate electrical signal transmission between the light emitting device 120 and a circuit board (not shown). The thin film substrate 110 may be formed of a conductive metal material such as copper (Cu) or aluminum (Al). Additionally, the thin film substrate 110 may be formed in a square or rectangular thin film shape.

The thin film substrate 110 includes a first sub-substrate 110a electrically connected to the first conductive metal layer (or first electrode pad) of the light emitting device 120, and a second conductive metal layer of the light emitting device 120. It may be composed of a second sub-board 110b that is electrically connected to (or a second electrode pad). The first sub-board 110a and the second sub-board 110b may be physically spaced apart by a certain distance for electrical insulation. The first and second sub-substrates 110a and 110b not only increase the electrode pad area of the light-emitting device 120, but also facilitate bonding between the light-emitting device 120 and the circuit board. You can.

The thin film substrate 110 supports the light emitting device 120 and may serve to reflect light emitted from the light emitting device 120. Accordingly, the light emitted from the light emitting device 120 may be reflected through the upper surface of the thin film substrate 110 and emitted toward the side of the light emitting device package 100. Meanwhile, in order to increase the reflection efficiency of the thin film substrate 110, a highly reflective metal material (eg, Ag, Pt, Au, etc.) may be coated on the upper surface of the thin film substrate 110.

The thin film substrate 110 may function as a heat sink that dissipates heat generated by the light emitting device 120 to the outside. That is, the thin film substrate 110 is disposed below the light emitting device 120, and can quickly dissipate heat generated from the light emitting device 120 toward the circuit board (i.e., the bottom).

The light emitting device (or LED chip, 120) is disposed on the thin film substrate 110 and can emit light in an upward direction. The light emitting device mounted on the thin film substrate 110 may be a flip-chip type light emitting device, but is not necessarily limited thereto.

The light emitting device 120 includes a growth substrate, a first conductive semiconductor layer under the growth substrate, an active layer under the first conductive semiconductor layer, a second conductive semiconductor layer under the active layer, and a second conductive semiconductor layer. It may include a second conductive metal layer below and a first conductive metal layer below the first conductive semiconductor layer.

The light emitting device 120 may emit light of different wavelengths depending on the composition ratio of the compound semiconductor. In this embodiment, the light emitting device 120 is illustrated as a blue LED device that emits light with a blue wavelength, but is not necessarily limited thereto. Meanwhile, although not shown in the drawing, a wavelength conversion layer may be formed on the upper surface of the light emitting device 120.

The molding member (or filling member, 130) may be disposed on the thin film substrate 110 and the light emitting device 120 and may be formed to surround the entire top and side surfaces of the light emitting device 120.

The molding member 130 protects the light emitting device 120 from the external environment or external shock, and together with the reflective member 150, forms the body of the light emitting device package 100 (hereinafter, for convenience of explanation, referred to as the 'package body'). ) can play a role in forming. Additionally, the molding member 130 may serve to transmit light emitted from the light emitting device 120 to the outside.

The molding member 130 may be formed of epoxy resin or silicone resin with excellent light transparency and thermal conductivity, but is not necessarily limited thereto. The molding member 130 may additionally include a light conversion material for converting the wavelength of light emitted from the light emitting device 120. In addition, the molding member 130 may additionally contain an adhesive material to improve the adhesive force between the molding member 130 and the thin film substrate 110 and the adhesive force between the molding member 130 and the light emitting device 120.

The molding member 130 may be formed on the thin film substrate 110 and the light emitting device 120 using an appropriate molding method, such as injection molding or transfer molding.

The lower surface of the molding member 130 may be disposed to face the upper surface of the thin film substrate 110 and the light emitting device 120. The overall shape of the lower surface of the molding member 130 may correspond to the overall shape of the upper surface of the thin film substrate 110. For example, the lower surface of the molding member 130 may be formed in a square or rectangular shape. Additionally, the side surface of the molding member 130 may be formed in a rectangular shape.

The upper surface of the molding member 130 may be disposed to face the reflective layer 140 or the lower surface of the reflective member 150. The upper surface (or upper part) of the molding member 130 may be composed of a flat portion 131 and a recessed portion 133.

The flat portion 131 may be formed to extend a certain distance from the top of the side of the molding member 130 in a direction perpendicular to the side of the molding member 130. The flat portion 131 may be formed in an upper edge area of the molding member 130.

The recessed portion 133 may be formed to be convexly recessed toward the center of the upper surface of the light emitting device 120. That is, the depression 133 may be formed to have a convex shape whose height gradually increases from the center point to the edge area. The depression 133 may be formed in the central area of the upper surface of the molding member 130.

The depression 133 may be formed to have an aspherical surface shape. The aspherical shape may be formed to converge toward the center at the edge area of the depression 133. The edge (or border) of the depression 133 may be formed in a circular shape.

The reflective member 150 may be formed on the molding member 130 or the upper surface of the reflective layer 140. The reflective member 150 may be formed on the molding member 130 or the reflective layer 140 using an appropriate molding method, such as injection molding or transfer molding.

The reflective member 150 forms the body of the light emitting device package 100 together with the molding member 130, and can reflect light emitted from the light emitting device 120 toward the side of the package body.

The reflective member 150 may be formed of epoxy resin or silicone resin with excellent reflective properties, but is not necessarily limited thereto. The reflective member 140 may include a light scattering material such as titanium dioxide (TiO ₂ ) or silicon dioxide (SiO ₂ ) to increase reflection characteristics.

The lower surface of the reflective member 150 may be disposed to face the upper surface of the molding member 130 or the reflective layer 140. The lower part of the reflective member 150 may be formed in a shape corresponding to the upper shape of the molding member 130.

The top and side surfaces of the reflective member 150 may be formed in a square or rectangular shape. The lower surface (or lower part) of the reflective member 150 may be composed of a flat portion 151 and a protruding portion 153.

The flat portion 151 may be formed to correspond to the flat portion 131 formed on the upper surface of the molding member 130. That is, the flat portion 151 may be formed to extend a certain distance from the bottom of the side of the reflective member 150 in a direction perpendicular to the side of the reflective member 150. Additionally, the flat portion 151 may be formed in an edge area of the lower surface of the reflective member 150.

The protrusion 153 may be formed to correspond to the depression 133 formed on the upper surface of the molding member 130. That is, the protrusion 153 may be formed to protrude concavely toward the center of the top surface of the light emitting device 120. Additionally, the protrusion 153 may be formed in the central area of the lower surface of the reflective member 150.

The protrusion 153 may be formed to have an aspherical surface shape. The aspherical shape may be formed to converge toward the center at the edge area of the protrusion 153. The edge (or border) of the protrusion 153 may be formed in a circular shape.

The protrusion 153 formed on the lower part of the reflective member 150 may be formed to have a concave shape whose height gradually increases from the edge area to the center point. The central portion of the reflective member 150 may be formed to have a thickness at least twice that of the edge region.

The depression 143 of the molding member 130 and the protrusion 153 of the reflection member 150 may be formed to coincide with the central optical axis of the light emitting device 120. In addition, the reflection member 150 and the molding member 130 may be coupled to face each other to form a package body in the shape of a rectangular parallelepiped or cube. Here, the upper part of the molding member 130 may be formed in an aspherical shape that is convexly depressed toward the center of the upper surface, and the lower part of the reflective member 150 may be formed in an aspherical shape that protrudes concavely in the central direction of the lower surface. there is. Accordingly, the package body can be formed to have a constant cross-sectional area regardless of its height.

An aspherical boundary surface (or reflective surface) may be formed between the molding member 130 and the reflective member 150. Light emitted from the light emitting device 120 can be reflected toward the side of the package body through this aspherical boundary surface. Accordingly, in the light emitting device package 100 according to the present invention, the specific gravity of the side light becomes larger than the specific gravity of the upper light. The radius of curvature of the aspherical shape formed between the molding member 130 and the reflective member 150 may be appropriately selected in consideration of light reflection efficiency and formability.

A reflective layer 140 may be formed between the molding member 130 and the reflective member 150. The reflective layer 140 may be thinly laminated or coded on the upper surface of the molding member 130.

The reflective layer 140 may be formed of a distributed bragg reflector (DBR) in which two or more insulating layers or conductive layers with different refractive indices are alternately stacked. Additionally, the reflective layer 140 may be formed of a metal material with high reflectivity. The metal material with high reflectance includes any one of aluminum (Al), silver (Ag), platinum (Pt), palladium (Pd), gold (Au), rhodium (Rh), chromium (Cr), and combinations thereof. may be used and is not necessarily limited thereto.

As described above, the light emitting device package according to the first embodiment of the present invention reflects the light radiating upward from the light emitting device in the horizontal direction through the aspherical boundary surface where the molding member and the reflection member meet to form a surface light source. can be implemented easily.

Figure 2a is a perspective view of a light emitting device package according to a second embodiment of the present invention, Figure 2b is a cross-sectional view of a light emitting device package according to a second embodiment of the present invention, and Figure 2c is a perspective view of a light emitting device package according to a second embodiment of the present invention. This is an exploded perspective view of the light emitting device package.

2A to 2C, the light emitting device package 200 according to the second embodiment of the present invention includes a thin film substrate 210, a light emitting device 220 disposed on the thin film substrate 210, and the light emitting device It may include a molding member 230 surrounding 220, a reflective layer 240 disposed on the molding member 230, and a reflective member 250 disposed on the reflective layer 240. Here, the reflective layer 240 may be configured to be omitted depending on the embodiment.

The elements constituting the light emitting device package 200 according to this embodiment are the same or similar to the elements constituting the light emitting device package 100 shown in FIGS. 1A to 1C described above, so the description will focus on the differences. do.

The light emitting device package 200 can implement a planar light source by reflecting light radiating upward from the light emitting device 220 in the horizontal direction through an aspherical boundary surface where the molding member 230 and the reflecting member 250 meet. there is. This light emitting device package 200 may be formed in a cylindrical shape, but is not necessarily limited thereto.

The thin film substrate 210 is electrically connected to the light emitting device 220 and may serve to mediate electrical signal transmission between the light emitting device 220 and the circuit board (not shown). The thin film substrate 210 may be formed in a circular thin film shape.

The thin film substrate 210 includes a first sub-substrate 210a electrically connected to the first conductive metal layer of the light-emitting device 220, and a second sub-substrate 210a electrically connected to the second conductive metal layer of the light-emitting device 220. It may be composed of a sub-substrate 210b. The first sub-board 210a and the second sub-board 210b may be physically spaced apart by a certain distance for electrical insulation.

The light emitting device 220 is disposed on the thin film substrate 210 and can emit light in an upward direction. The light emitting device mounted on the thin film substrate 210 may be a flip chip type light emitting device, but is not necessarily limited thereto.

The molding member 230 is disposed on the thin film substrate 210 and the light emitting device 220 and may be formed to surround the entire top and side surfaces of the light emitting device 220. The molding member 230 may be formed on the thin film substrate 210 and the light emitting device 220 using an appropriate molding method, such as injection molding or transfer molding.

The molding member 230 may serve to protect the light emitting device 220 from the external environment or external impacts, and form the body of the light emitting device package 200 together with the reflective member 250. Additionally, the molding member 230 may serve to transmit light emitted from the light emitting device 220 to the outside.

The lower surface of the molding member 230 may be disposed to face the upper surface of the thin film substrate 210 and the light emitting device 220. The overall shape of the lower surface of the molding member 230 may correspond to the overall shape of the upper surface of the thin film substrate 210. For example, the lower surface of the molding member 230 may be formed in a circular shape.

The upper surface of the molding member 230 may be disposed to face the reflective layer 240 or the lower surface of the reflective member 250. The upper edge (or border) of the molding member 230 may be formed in a circular shape.

The upper surface (or upper part) of the molding member 230 may be formed to be convexly depressed toward the center of the upper surface of the light emitting device 220. That is, the molding member 230 may be formed to have a convex shape whose height gradually increases from the center point of the upper surface to the edge. In addition, the cross section of the molding member 230 may be formed to have a shape that is left and right symmetrical.

The upper surface of the molding member 230 may be formed to have an aspherical shape. The aspherical shape may be formed to converge toward the center at the upper edge area of the molding member 230.

The reflective member 250 may be formed on the molding member 230 or the upper surface of the reflective layer 240. The reflective member 250 may be formed on the molding member 230 or the reflective layer 240 using an appropriate molding method, such as injection molding or transfer molding.

The reflective member 250 forms the body of the light emitting device package 200 together with the molding member 230, and can reflect light emitted from the light emitting device 220 toward the side of the package body.

The lower surface of the reflective member 250 may be disposed to face the upper surface of the molding member 230 or the reflective layer 240. The lower part of the reflective member 250 may be formed in a shape corresponding to the upper shape of the molding member 230.

The upper surface of the reflective member 250 may be formed in a circular shape. Additionally, the edge (or border) of the lower surface of the reflective member 250 may also be formed in a circular shape.

The lower surface (or lower part) of the reflective member 250 may be formed to protrude concavely toward the center of the upper surface of the light emitting device 220. Additionally, the lower surface of the reflective member 250 may be formed to have an aspherical shape. The aspherical shape may be formed to converge toward the center at the edge area of the lower surface of the reflective member 250.

The reflective member 250 may be formed to have a concave shape whose height gradually increases from the edge of the lower surface to the center point. The cross section of the reflective member 250 may be formed to have a shape that is left and right symmetrical. Additionally, the central portion of the reflective member 250 may be formed to have a thickness at least twice that of the edge region.

The depression 243 of the molding member 230 and the protrusion 253 of the reflection member 250 may be formed to coincide with the central optical axis of the light emitting device 220. Additionally, the reflective member 250 and the molding member 230 may be coupled to face each other to form a cylindrical package body. Here, the upper part of the molding member 230 may be formed in an aspherical shape that is convexly depressed toward the center of the upper surface, and the lower part of the reflective member 250 may be formed in an aspherical shape that protrudes concavely in the central direction of the lower surface. there is. Accordingly, the package body can be formed to have a constant cross-sectional area regardless of its height.

An aspherical boundary surface (or reflective surface) may be formed between the molding member 230 and the reflective member 250. Light emitted from the light emitting device 220 can be reflected toward the side of the package body through this aspherical boundary surface. At this time, the radius of curvature of the aspherical shape formed between the molding member 230 and the reflective member 250 may be appropriately selected in consideration of light reflection efficiency and formability.

A reflective layer 240 may be formed between the molding member 230 and the reflective member 250. The reflective layer 240 may be thinly laminated or coded on the upper surface of the molding member 230.

Meanwhile, in another embodiment, the upper surface of the molding member 230 may be composed of a flat portion and a recessed portion. In this case, the lower surface of the reflective member 250 may also be composed of a flat portion corresponding to the flat portion of the molding member and a protrusion corresponding to the recessed portion of the molding member.

As described above, the light-emitting device package according to the second embodiment of the present invention reflects the light radiating upward from the light-emitting device in the horizontal direction through the aspherical boundary surface where the molding member and the reflection member meet to form a surface light source. can be implemented easily.

FIG. 3A is a perspective view of a light-emitting device package according to a third embodiment of the present invention, FIG. 3B is a cross-sectional view of a light-emitting device package according to a third embodiment of the present invention, and FIG. 3C is a perspective view of a light-emitting device package according to a third embodiment of the present invention. This is an exploded perspective view of the light emitting device package.

Referring to FIGS. 3A to 3C, the light emitting device package 300 according to the third embodiment of the present invention includes a thin film substrate 310, a light emitting device 320 disposed on the thin film substrate 310, and the light emitting device It may include a molding member 330 surrounding the 320, a reflective layer 340 disposed on the molding member 330, and a reflective member 350 disposed on the reflective layer 340. Here, the reflective layer 340 may be configured to be omitted depending on the embodiment.

The elements constituting the light emitting device package 300 according to this embodiment are the same or similar to the elements constituting the light emitting device package 100 shown in FIGS. 1A to 1C described above, so the description will focus on the differences. do.

The light emitting device package 300 can implement a planar light source by reflecting light radiating upward from the light emitting device 320 in the horizontal direction through a flat inclined surface where the molding member 330 and the reflecting member 350 meet. This light emitting device package 300 may be formed in a cubic shape, a rectangular parallelepiped shape, or a cylindrical shape, but is not necessarily limited thereto.

The molding member 330 is disposed on the thin film substrate 310 and the light emitting device 320 and may be formed to surround the entire top and side surfaces of the light emitting device 320. The molding member 330 may be formed on the thin film substrate 310 and the light emitting device 320 using an appropriate molding method, such as injection molding or transfer molding.

The lower surface of the molding member 330 may be disposed to face the upper surface of the thin film substrate 310 and the light emitting device 320. The overall shape of the lower surface of the molding member 330 may correspond to the overall shape of the upper surface of the thin film substrate 310.

The upper surface (or upper part) of the molding member 330 may be formed to be depressed toward the center of the upper surface of the light emitting device 320. That is, the molding member 330 may be formed to have a shape whose height gradually increases from the center point of the upper surface to the edge area. For example, when the light emitting device package 300 has a cube or rectangular parallelepiped shape, the upper part of the molding member 330 may be formed to be depressed in the shape of an inverted square pyramid. Meanwhile, when the light emitting device package 300 has a cylindrical shape, the upper part of the molding member 330 may be formed to be recessed into an inverted cone shape.

The reflective member 350 may be formed on the molding member 330 or the upper surface of the reflective layer 340. The reflective member 350 may be formed on the molding member 330 or the reflective layer 340 using an appropriate molding method, such as injection molding or transfer molding.

The lower surface of the reflective member 350 may be disposed to face the upper surface of the molding member 330 or the reflective layer 340. The lower part of the reflective member 350 may be formed in a shape corresponding to the upper shape of the molding member 330.

The lower surface (or lower part) of the reflective member 350 may be formed to protrude toward the center of the upper surface of the light emitting device 320. That is, the reflective member 350 may be formed to have a shape whose height gradually increases from the edge area of the lower surface to the center point. For example, when the light emitting device package 300 has a cube or rectangular parallelepiped shape, the reflection member 350 may be formed in the shape of an inverted square pyramid. Meanwhile, when the light emitting device package 300 has a cylindrical shape, the reflective member 350 may be formed in an inverted cone shape.

The upper surface of the reflective member 350 may be formed in a circular, square, or rectangular shape, depending on the shape of the light emitting device package 300. The cross section of the reflective member 350 may be formed to have a shape that is left and right symmetrical. The reflection member 350 and the molding member 330 may be coupled to face each other to form a package body in the shape of a tetrahedron, a cube, or a cylinder.

A flat inclined surface (or reflective surface) may be formed between the molding member 330 and the reflective member 350. Light emitted from the light emitting device 320 can be reflected toward the side of the package body through this inclined surface. A reflective layer 340 may be formed between the molding member 330 and the reflective member 350.

As described above, the light-emitting device package according to the third embodiment of the present invention reflects the light radiating upward from the light-emitting device in the horizontal direction through a flat inclined surface where the molding member and the reflective member meet, thereby conveniently using a surface light source. It can be implemented.

FIGS. 4A to 4F are diagrams illustrating a method of manufacturing a light emitting device package according to an embodiment of the present invention.

Referring to FIGS. 4A and 4B, a support substrate 410 having a certain thickness and flatness can be prepared. The support substrate 410 may be formed of a glass material, a plastic material, a non-metal material, or a metal material with excellent adhesion to the thin film substrate 420, but is not necessarily limited thereto.

A detachable/attachable adhesive member (not shown) may be placed on the upper surface of the support substrate 410. The adhesive member may be formed in a shape corresponding to the overall shape of the support substrate 410.

A plurality of thin film substrates 420 may be arranged in a predetermined pattern on the upper surface of the adhesive member. For example, the thin film substrates 420 may be arranged in a matrix or lattice form on an adhesive member.

Each thin film substrate 420 may be composed of a first sub-substrate electrically connected to the first conductive metal layer of the light-emitting device and a second sub-substrate electrically connected to the second conductive-type metal layer of the light-emitting device. there is. The first sub-board and the second sub-board may be physically spaced apart from each other by a certain distance for electrical insulation.

Afterwards, a process of flip chip bonding the plurality of light emitting devices 430 on the upper surfaces of the plurality of thin film substrates 420 is performed. That is, a plurality of bumps (not shown) are disposed on the first and second sub-substrates of the plurality of thin film substrates 420. Then, the thin film substrate 420 and the plurality of light emitting devices 430 on which a plurality of bumps are disposed face each other, so that the first and second sub-substrates and the first and second light emitting devices 430 are 2 The conductive metal layers are placed in close contact with each other in one-to-one correspondence and then heated. Then, the plurality of bumps are melted, and thus the first and second sub-substrates and the corresponding first and second conductive metal layers are electrically connected.

Referring to FIGS. 4C and 4D , the molding member 440 is filled on the support substrate 410, the plurality of thin film substrates 420, and the plurality of light emitting devices 430. At this time, the molding member 440 is formed on the support substrate 410 on which the plurality of light emitting devices 440 are mounted using an appropriate molding method, such as injection molding or transfer molding. It can be.

The molding member 440 may be formed to entirely surround not only the upper surface of the support substrate 410 but also the plurality of thin film substrates 420 and the plurality of light emitting devices 430. The molding member 440 may be formed of epoxy resin or silicon resin, which has excellent light transparency and thermal conductivity.

The upper surface (or upper part) of the molding member 440 may be composed of a plurality of flat parts 441 and a plurality of recessed parts 443. The plurality of flat portions 441 may be formed at positions corresponding to the plurality of light-emitting devices 430, and the plurality of recessed portions 443 may be formed at upper portions of the plurality of light-emitting devices 430. It can be formed in position.

Each depression 443 may be formed to be convexly depressed toward the center of the upper surface of the light emitting elements 430. That is, the depression 443 may be formed to have a convex shape whose height gradually increases from the center point to the edge area.

Each depression 443 may be formed to have an aspherical surface shape. The aspherical shape may be formed to converge toward the center at the edge area of the depression 443. The edge (or border) of the depression 443 may be formed in a circular shape.

Afterwards, a reflective layer 450 is formed on the molding member 440. The reflective layer 450 may be coated to a thin thickness on the upper surface of the molding member 440. The process of forming the reflective layer 450 may be omitted depending on the embodiment.

The reflective layer 450 may be formed of a distributed bragg reflector (DBR) in which two or more insulating or conductive layers with different refractive indices are alternately stacked, or may be formed of a metal material with high reflectivity.

Referring to FIGS. 4E and 4F , the light emitting structure 470 is formed by filling the molding member 440 or the reflective layer 450 with a reflective member 460 . At this time, the reflective member 460 may be formed on the molding member 440 or the reflective layer 450 using an appropriate molding method, such as injection molding or transfer molding.

The reflective member 460 may form the body of the light emitting device package together with the molding member 440. The reflective member 460 may be formed of epoxy resin or silicone resin with excellent reflective properties.

The lower surface (or lower part) of the reflective member 460 may be composed of a plurality of flat parts 461 and a plurality of protrusions 463. The plurality of flat portions 461 may be formed at positions corresponding to the plurality of light-emitting devices 430, and the plurality of protrusions 463 may be formed at upper portions of the plurality of light-emitting devices 430. It can be formed in position.

Each flat part 461 may be formed to correspond to each flat part 441 formed on the upper surface of the molding member 440. Each protrusion 463 may be formed to correspond to each depression 443 formed on the upper surface of the molding member 440.

Each protrusion 463 may be formed to protrude concavely toward the center of the upper surface of the light emitting elements 430. That is, the protrusion 463 may be formed to have a concave shape whose height gradually increases from the edge area to the center point.

Each protrusion 463 may be formed to have an aspherical surface shape. The aspherical shape may be formed to converge toward the center at the edge area of the protrusion 463. The edge (or border) of the protrusion 463 may be formed in a circular shape.

Thereafter, the support substrate 410 and the adhesive member disposed under the light emitting structure 470 are removed, and then the light emitting structure 470 is separated into unit package areas through a package separation process to manufacture a plurality of light emitting device packages. You can. The package separation process includes, for example, a breaking process that separates the chips by applying physical force using a blade, a laser scribing process that separates the chips by irradiating a laser to the chip boundary, and wet etching or dry etching. It may include, but is not necessarily limited to, an etching process to separate chips.

Meanwhile, in another embodiment, the light emitting structure 470 is separated into unit package areas through a package separation process to manufacture a plurality of light emitting device packages, and then the support substrate 410 disposed below the light emitting device packages is removed. It may be possible.

FIG. 5A is a cross-sectional view of a backlight unit according to an embodiment of the present invention, and FIG. 5B is an exploded perspective view of a backlight unit according to an embodiment of the present invention.

Referring to FIGS. 5A and 5B, the backlight unit 500 according to an embodiment of the present invention includes a circuit board 510, a plurality of light emitting device packages 520 mounted on the circuit board 510, and the A reflective sheet assembly 530 disposed on a circuit board 510, a diffusion sheet 540 disposed on the reflective sheet assembly 530, and optical sheets 550 and 560 disposed on the diffusion sheet 540. may include.

The circuit board 510 supports a plurality of light emitting device packages 520 and can radiate heat generated from the light emitting device packages 520 to the outside. The circuit board 510 may be a printed circuit board (PCB) board or a flexible printed circuit board (FPCB) board, but is not necessarily limited thereto.

The circuit board 510 is electrically connected to the plurality of light emitting device packages 520 and may serve to mediate electrical signal transmission between the plurality of light emitting device packages 520 and external devices. To this end, the circuit board 510 may be provided with a circuit pattern (not shown) for driving a plurality of light emitting device packages 520.

The upper surface of the circuit board 510 may be thinly coated with a material to eliminate diffuse reflection of light emitted from the plurality of light emitting device packages 520 to the circuit board 510. The diffuse reflection removal material (or diffuse reflection removal member) coated on the circuit board 510 may be a highly reflective metal material (eg, Al, Ag, etc.). Meanwhile, in another embodiment, a black film or paint may be used as a diffuse reflection removal material coated on the circuit board 510.

This diffuse reflection removal material may be formed entirely on the entire circuit board area except for the area where the plurality of light emitting device packages 520 are mounted. For example, as shown in FIG. 6 , the diffuse reflection removal material 570 may be formed in a circuit board area corresponding to a peripheral area of the light emitting device package 520 to surround the light emitting device package 520 .

Meanwhile, in another embodiment, the diffuse reflection removal material is applied to the remaining circuit board areas excluding the area where the plurality of light emitting device packages 520 are mounted among the circuit board areas corresponding to the plurality of holes 533 formed in the reflective sheet assembly 530. It can only be formed in an area. That is, the diffuse reflection removal material is applied only to the circuit board area located between the inner side of the plurality of reflective sheet units 531 constituting the reflective sheet assembly 530 and the bottom surface of the corresponding light emitting device packages 520. can be formed.

A plurality of light emitting device packages 520 may be mounted on the upper surface of the circuit board 510 . At this time, the light emitting device packages 520 may be arranged in a predetermined pattern on the circuit board 510. As an example, the light emitting device packages 520 may be arranged in a matrix or lattice form.

Each light emitting device package 520 can implement a planar light source by reflecting light radiating upward from the light emitting device in the horizontal direction through an aspherical boundary surface where the molding member and the reflection member meet. This light emitting device package 520 may be formed in a cubic shape, a rectangular parallelepiped shape, or a cylindrical shape, but is not necessarily limited thereto.

The reflective sheet assembly 530 is disposed on the upper part of the circuit board 510 on which the plurality of light-emitting device packages 520 are mounted, and reflects light emitted in the side direction from the light-emitting device packages 520 in the upward direction. You can do it. The reflective sheet assembly 530 according to the present invention can simultaneously serve as a general reflective sheet and a light guide plate.

The reflective sheet assembly 530 may be formed using a plastic material such as polycarbonate or PMMA (polymethyl methacrylate), but is not necessarily limited thereto.

The reflective sheet units 531 constituting the reflective sheet assembly 530 are formed in a predetermined shape and can reflect light emitted from each light emitting device package 520 in the lateral direction upward.

For example, as shown in FIG. 7, the reflective sheet assembly 530 may be composed of a plurality of reflective sheet units 531 having the same shape. The plurality of reflective sheet units 531 may be arranged in a matrix or grid form. Additionally, the plurality of reflective sheet units 531 may be formed integrally or in an assembleable form.

Each reflective sheet unit 531 may be provided with a hole 533 for penetrating the light emitting device package 520 mounted on the circuit board 510. The hole 533 may be formed in the central portion of the reflective sheet unit 531. The size of the hole 533 may be larger than the size of the light emitting device package 520. Additionally, the hole 533 may be formed in a square shape, rectangular shape, or circular shape, but is not necessarily limited thereto.

The lower surface of the reflective sheet unit 531 may be disposed to face the upper surface of the circuit board 510. The lower surface of the reflective sheet unit 531 may be formed in a square or rectangular shape.

The upper surface (or upper portion) of the reflective sheet unit 531 may be formed to be concavely recessed in the direction of the light emitting device package 520 mounted on the circuit board 510. That is, the upper part of the reflective sheet unit 531 may be formed to have a concave shape whose height gradually increases from the hole area to the edge area.

The upper surface of the reflective sheet unit 531 may be formed as an inclined surface with a predetermined radius of curvature, that is, a curved shape (or parabolic shape). The curved shape may be formed to converge from the upper surface edge area of the reflective sheet unit 531 toward the hole located in the center of the unit 531.

The reflective sheet assembly 530 may include a plurality of protrusions 535 to maintain a constant distance from the diffusion sheet 540. The plurality of protrusions 535 may be formed on the top of the reflective sheet assembly 530. Additionally, the plurality of protrusions 535 may be formed at corner points where the plurality of reflective sheet units 531 meet.

The diffusion sheet 540 is disposed on the upper part of the reflective sheet assembly 530 and serves to spread the light evenly by scattering the light emitted from the plurality of light emitting device packages 520 and the reflective sheet assembly 530 in the upper direction. Perform.

The optical sheets 550 and 560 are disposed on the diffusion sheet 540 and serve to increase the brightness of the backlight unit 500 by refracting and concentrating light emitted from the diffusion sheet 540. The optical sheets 550 and 560 may be composed of a first prism sheet 550 arranged in a vertical direction and a second prism sheet 560 arranged in a horizontal direction.

As described above, the backlight unit according to an embodiment of the present invention arranges a reflective sheet assembly of a predetermined shape on a circuit board on which a plurality of light-emitting device packages are mounted, and uses a surface light source emitted from the light-emitting device packages. Light uniformity can be improved.

Meanwhile, although the specific embodiments of the present invention have been described above, it goes without saying that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, and should be determined by the claims and equivalents thereof as well as the claims described later.

100/200/300: Light emitting device package 110/210/310: Thin film substrate
120/220/320: Light emitting element 130/230/330: Molding member
140/240/340: reflective layer 150/250/350: reflective member
500: backlight unit 510: circuit board
520: Light emitting device package 530: Reflective sheet assembly
540: Diffusion sheet 550/560: Optical sheet

Claims (20)

a thin film substrate on which a first sub-substrate and a second sub-substrate are formed;
a light emitting device including a first electrode pad located on the first sub-substrate and a second electrode pad located on the second sub-substrate;
a molding member surrounding the upper surface of the thin film substrate and the side and upper surfaces of the light emitting device and transmitting light emitted from the light emitting device; and
It is formed on an upper part of the molding member and includes a reflective member that reflects light emitted from the light emitting element,
The reflective member changes the top light of the light emitting element into side light,
Characterized in that the specific gravity of the side light is greater than the specific gravity of the upper light,
The upper surface of the molding member includes a first flat portion extending from the top of a side of the molding member in a direction perpendicular to the side,
The lower surface of the reflective member includes a second flat portion extending from a lower side of the reflective member in a direction perpendicular to the side of the reflective member. According to paragraph 1,
A light emitting device package further comprising a reflective layer disposed between the molding member and the reflective member. According to paragraph 2,
A light emitting device package, wherein the reflective layer is formed of a distributed bragg reflector (DBR) in which two or more insulating layers or conductive layers with different refractive indices are alternately stacked. delete According to paragraph 1,
The upper surface of the molding member further includes a depression depressed in the direction of the light emitting element,
A light emitting device package, wherein the lower surface of the reflective member further includes a protrusion protruding in the direction of the light emitting device. According to clause 5,
A light emitting device package, wherein the depression and the protrusion coincide with a central optical axis of the light emitting device. According to clause 5,
The depression is formed to have a first aspherical shape that converges from the edge area toward the center,
A light emitting device package, wherein the protrusion is formed to have a second aspherical shape that converges from an edge area toward the center. According to paragraph 1,
The upper surface of the molding member is formed to be depressed from the first flat portion toward the center of the upper surface of the light emitting device,
A light emitting device package, wherein the lower surface of the reflective member is formed to protrude from the second flat portion toward the center of the upper surface of the light emitting device. According to paragraph 1,
A light emitting device package, characterized in that a wavelength conversion layer is formed on the upper surface of the light emitting device. According to paragraph 1,
A light emitting device package, wherein the reflective member includes a light scattering material such as titanium dioxide (TiO ₂ ) or silicon dioxide (SiO ₂ ). According to paragraph 1,
The molding member is combined with the reflective member to form a package body, and the package body is formed in a cylindrical shape. circuit board;
a plurality of light emitting device packages mounted on the circuit board;
a reflective sheet assembly formed on the circuit board and made of a plurality of reflective sheet units; and
It includes a diffusion sheet disposed on top of the reflective sheet assembly,
The reflective sheet units are formed of holes surrounding the light emitting device package and a plurality of inclined surfaces extending from the holes and having a radius of curvature,
The inclined surfaces change the side light of the light emitting device packages into top light,
The reflective sheet assembly is a backlight unit comprising a plurality of protrusions to maintain a constant distance from the diffusion sheet. According to clause 12,
A backlight unit, wherein each reflective sheet unit is formed to be concavely recessed from the edge area of the upper surface in the direction of the light emitting device package mounted on the circuit board. delete According to clause 12,
The backlight unit, wherein the plurality of protrusions are formed on an upper part of the reflective sheet assembly corresponding to a point where the plurality of reflective sheet units meet each other. According to clause 12,
The backlight unit is characterized in that the reflective sheet assembly is formed of polycarbonate (polycarbonate) or PMMA (polymethyl methacrylate) material. circuit board;
a plurality of light emitting device packages mounted on the circuit board;
a reflective sheet assembly formed on the circuit board and made of a plurality of reflective sheet units; and
It includes a diffusion sheet disposed on top of the reflective sheet assembly,
The reflective sheet units are formed of holes surrounding the light emitting device package and a plurality of inclined surfaces extending from the holes and having a radius of curvature,
The inclined surfaces change the side light of the light emitting device packages into top light,
A backlight unit, characterized in that a diffuse reflection removal member exposed by the holes is formed on the upper surface of the circuit board. According to clause 12,
The light emitting device packages are each
A light emitting device disposed on a thin film substrate;
a molding member surrounding the upper surface of the thin film substrate and the side and upper surfaces of the light emitting device and transmitting light emitted from the light emitting device; and
It is formed on an upper part of the molding member and includes a reflective member that reflects light emitted from the light emitting element,
A backlight unit characterized in that the light emitted from the light emitting device package has a higher proportion of side light than top light. According to clause 18,
The upper surface of the molding member includes a depression depressed in the direction of the light emitting element,
A backlight unit wherein the lower surface of the reflective member includes a protrusion protruding in the direction of the light emitting device. According to clause 19,
The backlight unit, wherein the depression and the protrusion coincide with a central optical axis of the light emitting device.

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