Light emitting device package

Embodiments of the present invention relate to a light emitting device package having uniform color characteristics, wherein the light emitting device package includes: a substrate including first and second lead frames; at least two light emitting devices disposed on the substrate and electrically connected to the first and second lead frames; an integrated wavelength conversion film disposed on the at least two light emitting devices and including a first region which overlaps the light emitting devices and a second region other than the first region; at least one recess which passes through the wavelength conversion film in a region corresponding to a gap between the adjacent light emitting devices; and a lens disposed on the substrate to cover the light emitting devices and the first and second lead frames.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0052426, filed on Apr. 28, 2016, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a light emitting device package having uniform color characteristics.

2. Discussion of Related Art

A light emitting diode (LED) is one of devices configured to emit light when a current is supplied thereto. Since LEDs can highly and efficiently emit light using a low voltage, LEDs have an excellent energy-saving effect. Recently, a brightness problem of LEDs has been significantly solved, and thus LEDs are being used for various devices such as a backlight unit (BLU) of a liquid crystal display (LCD) apparatus, an electric signboard, an indicator, and a home appliance.

An LED may have a structure in which a first electrode and a second electrode are disposed at one side of an emitting structure including a first semiconductor layer, an active layer, and a second semiconductor layer. In addition, the first electrode and the second electrode may be electrically connected to an external circuit through a lead frame.

A light emitting device package includes two or more of the above-described LED mounted on a substrate and can generate white light. However, in this case, wavelength conversion films are attached to the LEDs, and thus an adhesive force of the wavelength conversion film for each LED may vary. Accordingly, color uniformity thereof may be decreased.

SUMMARY OF THE INVENTION

The present invention is directed to a light emitting device package in which at least two light emitting devices share one wavelength conversion film.

According to an aspect of the present invention, there is provided a light emitting device package including: a substrate including first and second lead frames; at least two light emitting devices disposed on the substrate and electrically connected to the first and second lead frames; an integrated wavelength conversion film disposed on the at least two light emitting devices and including a first region which overlaps the light emitting devices and a second region other than the first region; at least one recess which passes through the wavelength conversion film in a region corresponding to a gap between the adjacent light emitting devices; and a lens disposed on the substrate to cover the light emitting devices and the first and second lead frames.

According to another aspect of the present invention, there is provided a light emitting device package including: a substrate including first and second lead frames; at least two light emitting devices disposed on the substrate and electrically connected to the first and second lead frames; an integrated wavelength conversion film disposed on the at least two light emitting devices and including a first region which overlaps the light emitting devices and a second region other than the first region; a reflective member which surrounds the side surfaces of the light emitting devices along an edge of the wavelength conversion film; at least one recess which passes through the wavelength conversion film in a region corresponding to a gap between the adjacent light emitting devices; and a lens disposed on the substrate to cover the light emitting devices and the first and second lead frames.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

While the invention may be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. However, it should be understood that there is no intent to limit the invention to the particular forms disclosed and that the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.

Although terms including ordinal terms such as first, second, and the like may be used herein in reference to elements of the invention, such elements are not to be construed as limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element and a second element could be termed a first element without departing from the scope of the present invention. Herein, the term “and/or” includes any and all combinations of one or more referents.

It should be understood that when an element is referred to as being “connected” or “coupled” to another element, the element can be directly connected or coupled to the other element, or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements.

The terminology used herein to describe embodiments of the invention is not intended to limit the scope of the invention. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document does not preclude the presence of more than one referent. In other words, elements of the invention referred to in the singular may number one or more unless the context clearly indicates otherwise. It should be further understood that the terms “comprise,” “comprising,” “include,” and/or “including,” when used herein, specify the presence of stated features, numbers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof.

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, and the same or corresponding elements will be consistently denoted by the same reference numerals and will not be repeatedly described regardless of the reference numerals.

Hereinafter, a light emitting device package according to an embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1Ais a plan view illustrating a light emitting device package according to a first embodiment of the present invention, andFIGS. 1B and 1Care cross-sectional views taken along line I-I′ ofFIG. 1A. In addition,FIG. 1Dis a plan view illustrating a wavelength conversion film inFIG. 1A.

As shown inFIGS. 1A, 1B and 1D, the light emitting device package according to the first embodiment of the present invention includes a substrate100having first and second lead frames115aand115b, at least two of light emitting devices120a,120b,120c, and120ddisposed on the substrate100and electrically connected to the first and second lead frames115aand115b, an integrated wavelength conversion film130disposed on at least two of the light emitting devices120a,120b,120c, and120dand having a first region130a, which overlaps at least two of the light emitting devices120a,120b,120c, and120d, and a second region130bother than the first region130a, at least one recess140which passes through the wavelength conversion film130to correspond to gaps between the light emitting devices120a,120b,120c, and120d, and a lens150disposed on the substrate100to cover the light emitting devices120a,120b,120c, and120dand the first and second lead frames115aand115b.

The lens150may be made of a transparent resin so that light emitted from the light emitting devices120a,120b,120c, and120dis easily emitted to the outside, but is not limited thereto. The lens150may be formed to have a structure in which an upper surface thereof has a convex dome shape as illustrated so that a directional angle of light emitted from the light emitting device package is improved, but is not limited thereto and may be formed in any of various shapes.

The lens150may be directly formed on the substrate100by a molding method, such as a compression molding method or transfer molding method, or a porting method using a dispenser, or may be manufactured by a separate process and attached to the substrate100. Particularly, when the lens150is formed using a molding or porting method, a transparent resin may also be filled between adjacent light emitting devices120a,120b,120c, and120dthrough the recess140which passes through the wavelength conversion film130in the light emitting device package according to the embodiment of the present invention.

The substrate100may be a ceramic substrate, but is not limited thereto. For example, the substrate100may be a ceramic insulating layer made of a nitride or oxide. The above-described substrate100may be made of SiO2, SixOy, Si3N4, SixNy, SiOxNy, Al2O3, or AlN, but is not limited thereto.

The first and second lead frames115aand115bmay include a conductive material such as Cu or Au having a high conductivity, but is not limited thereto. In addition, the first and second lead frames115aand115bmay include a reflective material such as Al and may transmit light emitted by the light emitting devices120a,120b,120c, and120dtoward the lens150. The above-described first and second lead frames115aand115bare electrically separated and may be connected to first and second electrodes (not shown) of each of the light emitting devices120a,120b,120c, and120d. Through such a structure, a current or the like may be supplied to the light emitting devices120a,120b,120c, and120dthrough the first and second lead frames115aand115b, and thus light may be generated by the light emitting devices120a,120b,120c, and120d. In addition, shapes of the first and second lead frames115aand115bare not limited to those in the drawings and may be easily changed.

The light emitting devices120a,120b,120c, and120dmay be disposed on the substrate100and electrically connected to the first and second lead frames115aand115b. The light emitting devices120a,120b,120c, and120dmay have a vertical structure, a flip chip structure, or the like, but is not limited thereto. For example, when the light emitting devices120a,120b,120c, and120dhave a flip chip structure, the light emitting devices120a,120b,120c, and120dare directly connected to the first and second lead frames115aand115bwithout a wire. In addition, when the light emitting devices120a,120b,120c, and120dhave a vertical structure, the light emitting devices120a,120b,120c, and120dmay be electrically connected to the first and second lead frames115aand115bthrough wires.

The light emitting devices120a,120b,120c, and120dare illustrated in the drawings to be disposed in a 2×2 matrix form, but an arrangement of the light emitting devices120a,120b,120c, and120dis not limited thereto and may be easily adjusted.

FIG. 1Eis a cross-sectional view illustrating the light emitting device ofFIG. 1Band shows a flip chip structure.

As illustrated inFIG. 1E, the light emitting device120aincludes a light emitting structure11having a first semiconductor layer12, an active layer13, and a second semiconductor layer14, a first electrode16aconnected to the first semiconductor layer12, a second electrode16bconnected to the second semiconductor layer14, and first and second electrode pads17aand17brespectively connected to the first and second electrodes16aand16b.

The first semiconductor layer12may be formed using a compound semiconductor included in a III-V group, a II-VI group, or the like and may be doped with a first dopant. The first semiconductor layer12may include a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N, wherein 0≤x1≤1, 0≤y1≤1, and 0≤(x1+y1)≤1, and may be selected from, for example, GaN, AlGaN, InGaN, InAlGaN, etc. In addition, the first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first semiconductor layer12doped with the first dopant may be an n-type semiconductor layer.

The active layer13is a layer in which electrons (or holes) injected through the first semiconductor layer12are coupled to holes (or electrons) injected through the second semiconductor layer14. As the electrons and holes are recombined to transition to a low energy level, the active layer13may generate light having a wavelength corresponding thereto.

The active layer13may have one structure among a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure, but is not limited thereto.

The second semiconductor layer14is formed on the active layer13and may be made of a compound semiconductor included in a III-V group, a II-IV group, or the like, and may be doped with a second dopant. The second semiconductor layer14may be made of a semiconductor material having a compound formula of Inx5Aly2Ga1-x5-y2N, wherein 0≤x5≤1, 0≤y2≤1, and 0≤(x5+y2)≤1, or may be made of a material selected from among AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, and Ba, the second semiconductor layer14doped with the second dopant may be a p-type semiconductor layer.

The first electrode16amay be electrically connected to the first semiconductor layer12through a groove which passes through and exposes the active layer13and the second semiconductor layer14so that a part of a region of the first semiconductor layer12is exposed. Since a first insulating layer15ais disposed on side surfaces of the first semiconductor layer12, the active layer13, and the second semiconductor layer14exposed by the groove, the active layer13and the second semiconductor layer14are prevented from being connected to the first electrode16aand the first electrode pad17a. In addition, the second electrode16bis electrically connected to the second semiconductor layer14.

The first electrode16aand the second electrode16bmay be made of a material selected from a group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Ti, Cr, and Cu, but is not limited thereto. In addition, although not illustrated in the drawings, the first electrode16aand the second electrode16bmay also be electrically connected to the first and the second semiconductor layers12and14through an ohmic contact layer formed of a transparent conductive material such as indium tin oxide (ITO). The connection of the first electrode16aand the second electrode16bto the first and second semiconductor layers12and14is not limited thereto.

The second insulating layer15bmay be disposed between the first electrode16aand the second electrode16band between the first electrode pad17aand the second electrode pad17b.

The second insulating layer15bmay be made of a material configured to perform both insulation and reflection functions. For example, the second insulating layer15bmay include a distributed Bragg reflector (DBR).

Referring back toFIGS. 1A, 1B, and 1D, the wavelength conversion film130may be disposed on the above-described light emitting devices120a,120b,120c, and120d. When the first semiconductor layer12(seeFIG. 1E) is directly exposed to upper surfaces of the light emitting devices120a,120b,120c, and120das illustrated inFIG. 1E, the wavelength conversion film130is directly attached to the first semiconductor layer12(seeFIG. 1E), and when the light emitting devices120a,120b,120c, and120dinclude a support substrate (not shown) on the first semiconductor layer12(seeFIG. 1E), the wavelength conversion film130may be attached to the support substrate (not shown).

The wavelength conversion film130may be integrally disposed on the light emitting devices120a,120b,120c, and120d, and the light emitting devices120a,120b,120c, and120dmay share one wavelength conversion film130.

Meanwhile, edges of the wavelength conversion film130match edges of the light emitting devices120a,120b,120c, and120dor has a shape which protrudes from the edges of the light emitting devices120a,120b,120c, and120das illustrated inFIG. 1C.

When the edges of the wavelength conversion film130protrudes from the edges of the light emitting devices120a,120b,120c, and120das illustrated inFIG. 1C, light emitted from side surfaces of the light emitting devices120a,120b,120c, and120dmay be converted into white light through a protruding portion of the wavelength conversion film130. Accordingly, in this case, a color impression of the white light of the light emitting device package can be improved. In addition, when the wavelength conversion film130is attached to the light emitting devices120a,120b,120c, and120d, a process margin can be secured.

Accordingly, a distance L between the edges of the wavelength conversion film130and the edges of the light emitting devices120a,120b,120c, and120dmay be in the range of 50 to 150 μm, but is not limited thereto.

As illustrated inFIGS. 1A to 1E, the plurality of light emitting devices120a,120b,120c, and120dmay each be connected to the first and second lead frames115aand115b. In addition, the plurality of light emitting devices120a,120b,120c, and120dmay be sequentially connected in series, and the light emitting device120aand120dlocated at both ends thereof may be respectively connected to the first and second lead frames115aand115b.

But a connection is not limited thereto. Electric connection between light emitting devices may be easily changed. For example, the first and second lead frames115aand115bmay be connected to a plurality of light emitting devices120a,120b,120c, and120d, respectively, with different electrodes.

Through such a structure, the plurality of light emitting devices120a,120b,120c, and120din the light emitting device package may be connected in parallel.

FIG. 2Ais a plan view illustrating another structure of the light emitting device package according to the first embodiment of the present invention.

As illustrated inFIG. 2A, the plurality of light emitting devices120a,120b,120c, and120dmay be sequentially connected in series through connecting electrodes115c. In addition, two light emitting devices120aand120dlocated at both ends thereof may be respectively connected to the first and second lead frames115aand115b. Here, shapes of the first and the second lead frames115aand115band the connecting electrodes115care not limited to those illustrated in the drawings and may be easily changed. For example, the connecting electrode115cdisposed between the second light emitting device120band the third light emitting device120cmay be electrically connected to the first and second lead frames115aand115b. The connecting electrode115cbetween the first and second light emitting devices120aand120band the connection electrode115cbetween the third and fourth light emitting devices120cand120dmay be electrically connected. Through such a structure, the plurality of light emitting devices120a,120b,120c, and120din the light emitting device package may be connected in parallel. However, the present invention is not limited to such a connection, and the electrical connection between the light emitting elements may be easily changed.

Meanwhile, when the light emitting devices120a,120b,120c, and120dhave a vertical structure, the plurality of light emitting devices120a,120b,120c, and120dmay be connected as illustrated inFIG. 2B.

FIG. 2Bis a plan view illustrating still another structure of the light emitting device package according to the first embodiment of the present invention.

As illustrated inFIG. 2B, the plurality of light emitting devices120a,120b,120c, and120dmay be connected in series through wires220and first to fifth lead frames215a,215b,215c,215d, and215e. In the above-described vertical type light emitting device, the first electrode and the second electrode of the light emitting device are disposed at different sides. For example, when the first electrode of the first electrode and the second electrode of the light emitting device is directly connected to one lead frame selected from among the first to fifth lead frames215a,215b,215c,215d, and215e, the second electrode may be electrically connected to one lead frame selected from the lead frames which are not connected to the first electrode through a wire220. In the drawing, the second electrode is electrically connected to the lead frame through two wires.

Shapes of the first to fifth lead frames215a,215b,215c,215d, and215eand a connection structure of the plurality of light emitting devices120a,120b,120c, and120dare not limited thereto, and one or more of the light emitting devices selected from among the plurality of light emitting devices120a,120b,120c, and120dmay also be connected in parallel. For example, the first lead frame215amay be electrically connected to the third lead frame215cand the fifth lead frame215e, and the second lead frame215bmay be electrically connected to the fourth lead frame215d. Through such a structure, the plurality of light emitting devices120a,120b,120c, and120dmay be electrically connected in parallel. Thus, the connection structure between the light emitting devices may be variously changed.

FIGS. 3A and 3Bare photographs of a general light emitting device package.

As shown inFIGS. 3A and 3B, in the general light emitting device package, the number of light emitting devices disposed in the light emitting device package is the same as the number of wavelength conversion films. Since a wavelength conversion film is individually attached to a light emitting device in the above-described general light emitting device package, an adhesive force of the wavelength conversion film for each light emitting device may vary. In addition, since white light is not emitted between adjacent light emitting devices, uniform white light is not emitted from the light emitting device package.

On the other hand, as illustrated inFIGS. 1A, 1B, and 1C, since one wavelength conversion film130is attached to the plurality of light emitting devices120a,120b,120c, and120din the embodiment of the present invention, the wavelength conversion film130may be uniformly attached to the light emitting devices120a,120b,120c, and120d. Through such a structure, the adhesive force of the wavelength conversion film130may be equally applied to the light emitting devices120a,120b,120c, and120d. Accordingly, since an external force is uniformly distributed, reliability of the light emitting device package can be improved and a process thereof can be simplified. In addition, since light generated by the plurality of light emitting devices120a,120b,120c, and120dis converted into white light by being transmitted through one wavelength conversion film130, uniformity of the white light can be improved.

In addition, in the general light emitting device package, white light is not emitted from a region corresponding to a light emitting device in which a failure occurs among the plurality of light emitting devices. However, in the light emitting device package according to the embodiment of the present invention, even when there is a light emitting device in which a failure occurs among the plurality of light emitting devices120a,120b,120c, and120d, light emitted by the remaining light emitting devices which normally operate can be uniformly emitted as white light through the wavelength conversion film.

FIGS. 4A and 4Bare photographs of the light emitting device package according to the first embodiment of the present invention.

As illustrated inFIGS. 4A and 4B, in the light emitting device package according to the embodiment of the present invention, the integrated wavelength conversion film130is disposed on the plurality of light emitting devices120a,120b,120c, and120d. Here, an area of the integrated wavelength conversion film130attached to the plurality of light emitting devices120a,120b,120c, and120dis greater than that of general wavelength conversion films individually attached on the light emitting devices120a,120b,120c, and120d. That is, when the wavelength conversion film130having a large area is attached to the plurality of light emitting devices120a,120b,120c, and120d, the wavelength conversion film130may be warped or attachment properties thereof may be partially changed.

Accordingly, in the light emitting device package according to the embodiment of the present invention, the wavelength conversion film130may be attached to the light emitting devices120a,120b,120c, and120dusing an adhesive layer125in which a phenyl-based silicone and a methyl-based silicone are mixed.

Referring back toFIGS. 1A, 1B, and 1C, the adhesive layer125in a liquid state is applied on one side surface of the wavelength conversion film130, the wavelength conversion film130is attached to the light emitting devices120a,120b,120c, and120dusing the adhesive layer125, and the adhesive layer125may be cured. Here, when a viscosity of the liquid adhesive layer125is too low, the adhesive layer125may flow up to the side surfaces of the light emitting devices120a,120b,120c, and120d.

A hardness of the phenyl-based silicone is generally higher than that of the methyl-based silicone. In addition, stickiness and heat resistance of the methyl-based silicone are higher than that of the phenyl-based silicone, and the hardness of the methyl-based silicone is lower than that of the phenyl-based silicone. Accordingly, the adhesive layer125according to the embodiment of the present invention in which the phenyl-based silicone and the methyl-based silicone are mixed has a higher stickiness than an adhesive layer made of only the phenyl-based silicone and has a higher hardness than an adhesive layer made of only the methyl-based silicone.

Particularly, when content of the phenyl-based silicone is too much higher than that of the methyl-based silicone in the adhesive layer125, a hardness of the adhesive layer125is too high and the viscosity thereof is too low, and thus the adhesive layer125has a high probability of being cracked. Accordingly, the content of the phenyl-based silicone is lower than that of the methyl-based silicone included in the adhesive layer125, and the content of the phenyl-based silicone may be in the range of 20% to 40% of the adhesive layer125. More preferably, the content of the phenyl-based silicone may be 30% of the adhesive layer125. Here, the viscosity of the adhesive layer125may be easily adjusted by adjusting content of the phenyl-based silicone and the methyl-based silicone. In addition, the hardness of the cured adhesive layer125may be in the range of A50 to A60 and, for example, may be A55.

A thickness T of the wavelength conversion film130may be in the range of 50 to 100 μm. When the thickness T of the wavelength conversion film130is too low, the edge of the wavelength conversion film130is warped by heat generated when the light emitting device package is driven, and thus the wavelength conversion film130may be separated from the light emitting devices120a,120b,120c, and120d. In addition, when the thickness T of the wavelength conversion film130is 100 μm or more and the recess140is formed to pass through the wavelength conversion film130, forming precision thereof may be lowered.

The thickness of the wavelength conversion film130may be adjusted according to color characteristics of white light emitted from the light emitting device package. For example, when the white light emitted from the light emitting device package is cool white light, the thickness T of the wavelength conversion film130may be in the range of 50 to 80 μm, and when the white light emitted therefrom is neutral white light, the thickness T thereof may be in the range of 70 to 90 μm. In addition, when the white light emitted therefrom is warm white light, the thickness T thereof may be in the range of 80 to 100 μm.

Table 1 below is a comparative table for characteristics of a conventional light emitting device package and the light emitting device package according to the embodiment of the present invention, and deviations of correlated color temperature ΔCCT are compared.

Since wavelength conversion films are individually attached to light emitting devices in the conventional light emitting device package, an adhesive force of the wavelength conversion film for each light emitting diodes (LED) may vary. In addition, color uniformity thereof may be accordingly decreased. Accordingly, the ΔCCT thereof is high.

On the other hand, in the light emitting device package according to the embodiment of the present invention, since one wavelength conversion film is attached to the plurality of light emitting devices, the wavelength conversion film may be uniformly attached to the light emitting devices. Accordingly, color uniformity and color characteristics of light emitted from the light emitting device package are improved and the ΔCCT can be lowered.

Furthermore, when the number of light emitting devices120a,120b,120c, and120dis increased or a size of the light emitting device package is increased, an area of the wavelength conversion film130is also increased, and thus stress of the wavelength conversion film130may be generated. In this case, since the thickness of the wavelength conversion film130may be partially different, properties of light passing through the wavelength conversion film130may be nonuniform. In this case, color properties of the light emitting device package are lowered.

Accordingly, the wavelength conversion film130may include at least one recess140which passes through the wavelength conversion film130to relieve stress of the wavelength conversion film130. Here, the recess140may be disposed between adjacent light emitting devices120a,120b,120c, and120dso that the light emitting devices120a,120b,120c, and120dare not exposed in a region in which the recess140is formed. For example, the recess140may be formed in the second region130bof the wavelength conversion film130. Here, the number of the recess140may be increased as an area of the wavelength conversion film130is increased.

In addition, since the area of the wavelength conversion film130is increased as separation distances between the light emitting devices120a,120b,120c, and120dare increased, the number or diameters d of the recess140may be increased.

The diameter d of the recess140may be 40 μm or more and may be smaller than the separation distances between the light emitting devices120a,120b,120c, and120d. Here, since the recess140is a region from which the wavelength conversion film130is removed, when the diameter of the recess140is too big, the area of the wavelength conversion film130is decreased. For example, when the diameter of the recess140is too big, a light emitting efficiency of the light emitting device package is decreased, light emitted from the light emitting devices120a,120b,120c, and120dis directly emitted through the recess140, and thus the light may leak. Accordingly, the diameter d of the recess140may be in the range of 40 to 120 μm.

Specifically, when the light emitting device package is driven, the first region130aof the wavelength conversion film130which overlaps the light emitting devices120a,120b,120c, and120dis directly affected by heat generated when the light emitting devices120a,120b,120c, and120demit light. That is, although the first region130aof the wavelength conversion film130is expanded by heat generated by the light emitting devices120a,120b,120c, and120d, an influence on the second region130baccording to the heat generated by the light emitting devices120a,120b,120c, and120dmay be lower compared with the first region130a. Accordingly, when the light emitting device package is driven, degrees of expansion of the first region130aand the second region130bof the wavelength conversion film130may be different. In addition, as the light emitting device package is repeatedly turned on and off, the degrees of thermal expansion of the first region130aand the second region130bof the wavelength conversion film130are increased, and thus a crack of the wavelength conversion film130may occur or a crack of the lens150may occur.

Accordingly, the recess140formed in the second region130bof the wavelength conversion film130, that is, formed between adjacent light emitting devices120a,120b,120c, and120d, may relieve a difference in the degrees of thermal expansion of the first and second regions130aand130bof the wavelength conversion film130. Accordingly, the recess140may be disposed at a central portion of the wavelength conversion film130and may efficiently prevent a difference in degrees of thermal expansion in the wavelength conversion film130.

Furthermore, when a resin is molded to form the lens150, gaps between the light emitting devices120a,120b,120c, and120dmay be filled with the resin through the recess140. That is, a region in which the second region130bof the wavelength conversion film130overlaps the substrate100and an inside of the recess140may also be filled with the resin.

Accordingly, in the light emitting device package according to the embodiment of the present invention, the first region130aof the wavelength conversion film130is pressed against the light emitting devices120a,120b,120c, and120d, and the second region130bmay be pressed against the resin which fills the gaps between the light emitting devices120a,120b,120c, and120d. Through such a structure, the wavelength conversion film130may be stably disposed on the light emitting devices120a,120b,120c, and120d.

FIG. 5AandFIG. 5Bare plan views illustrating a wavelength conversion film including a plurality of recess.

Shapes of the recess140may be a shape selected from a circular shape, an oval shape, a polygonal shape, and the like as illustrated in the drawings. Particularly, it is preferable for the recess140to be formed in the central portion of the wavelength conversion film130to easily relieve the difference in the degrees of thermal expansion in the wavelength conversion film130. In addition, the recess140is not limited thereto and may be selectively formed at an edge of the wavelength conversion film130as illustrated inFIGS. 5A and 5B, and the number thereof may be one or more.

Particularly, as the number of recess140is increased, a degree of stress relief of the wavelength conversion film130is improved, and the gaps between the light emitting devices120a,120b,120c, and120dmay be easily filled with the resin for forming the lens150. In addition, when the number of recess140is two or more, the recess140may have different diameters d1and d2. In addition, a total sum of diameters of recess140having small diameters may be the same as a diameter of a largest recess140having the largest diameter.

In addition, the recess140may be disposed between adjacent light emitting devices120a,120b,120c, and120d. In addition, the recess140may be symmetrically disposed to uniformly remove the difference in the degrees of thermal expansion. In addition, a size of the recess140having a large diameter and adjacent to the light emitting devices120a,120b,120c, and120dmay be greater than that of the recess140having a small diameter and adjacent to the light emitting devices120a,120b,120c, and120d. Through such a structure, the difference in the degrees of thermal expansion in the wavelength conversion film130is relived, and thus reliability thereof can be improved.

FIG. 6Ais a plan view illustrating a light emitting device package according to a second embodiment of the present invention, andFIG. 6Bis a cross-sectional view taken along line I-I′ ofFIG. 6A. In addition,FIG. 6Cis another cross-sectional view taken along line I-I′ ofFIG. 6A.

As illustrated inFIGS. 6A and 6B, a light emitting device package according to a second embodiment of the present invention includes a substrate200having first and second lead frames215aand215b, at least two light emitting devices220a,220b,220c, and220ddisposed on the substrate200and electrically connected to first and second lead frames215aand215b, an integrated wavelength conversion film230disposed on at least two of the light emitting devices220a,220b,220c, and220dand having a first region230a, which overlaps upper surfaces of the light emitting devices220a,220b,220c, and220d, and a second region230bcorresponding to a region which separates the light emitting devices220a,220b,220c, and220d, a reflective member260which surrounds side surfaces of the light emitting devices220a,220b,220c, and220dalong an edge of the wavelength conversion film230, at least one recess240which passes through the wavelength conversion film230in a region corresponding to gaps between adjacent light emitting devices220a,220b,220c, and220d, and a lens250disposed on the substrate200to cover the light emitting devices220a,220b,220c, and220dand the first and second lead frames215aand215b.

The remaining components of the above-described light emitting device package according to the second embodiment of the present invention except the reflective member260are the same as those of the first embodiment of the present invention. Likewise, the electrical connection between the light emitting elements may be easily changed. For example, the first lead frame215aand the second lead frame215bmay be connected to a plurality of light emitting devices220a,220b,220c, and220d, respectively, with different electrodes. Through such a structure, the plurality of light emitting devices220a,220b,220c, and220din the light emitting device package may be connected in parallel.

The reflective member260may prevent a phenomenon in which light which is emitted from the side surfaces of the light emitting devices220a,220b,220c, and220dand does not to pass through the wavelength conversion film230leaks from a side surface of the light emitting device package. The reflective member260may include a white silicone such as a phenyl silicone and a methyl silicone and may also include reflective particles to improve a reflectivity thereof. For example, the reflective member260may also be glass in which TiO2is distributed, but is not limited thereto.

The above-described reflective member260may be formed by a reflective material being applied to cover the surfaces of the light emitting devices220aand220balong the edge of the wavelength conversion film230and cured. In addition, the reflective member260may have a structure in which an end thereof overlaps the wavelength conversion film230and completely surrounds the side surfaces of the light emitting devices220a,220b,220c, and220d. In addition, the reflective member260may cover a side surface of the wavelength conversion film230, but may not cover an upper surface of the wavelength conversion film230. Through such a structure, the reflective member260may reflect only light which is emitted from the side surfaces of the light emitting devices220a,220b,220c, and220dand does not pass through the wavelength conversion film230. Meanwhile, as illustrated inFIG. 6C, the reflective member260may be formed as a film type and may also be attached to and cover the side surfaces of the light emitting devices220aand220bexposed along the edge of the wavelength conversion film230.

FIGS. 7A and 7Bare photographs of light emission of a general light emitting device package, andFIGS. 8A and 8Bare photographs of light emission of the light emitting device package according to the second embodiment of the present invention.

As illustrated inFIGS. 7A and 7B, in the general light emitting device package, since wavelength conversion films are individually attached to light emitting devices, white light converted by the wavelength conversion films is not emitted between adjacent light emitting devices, and thus uniform white light is not emitted from the light emitting device package. Furthermore, since an adhesive force of the wavelength conversion film for each of the light emitting devices varies, velocities of light emitted from the light emitting devices also vary. Accordingly, the uniformity of white light is decreased in the general light emitting device package.

On the other hand, as illustrated inFIGS. 8A and 8B, in the light emitting device package according to the embodiment of the present invention, since the wavelength conversion film is also disposed between adjacent light emitting devices, the plurality of light emitting devices share one wavelength conversion film, and thus white light may be uniformly emitted from the light emitting device package.

As described above, in the light emitting device package according to the embodiment of the present invention, since at least two light emitting devices share one wavelength conversion film, color uniformity and color characteristics of light emitted from the light emitting device package are improved. In addition, since the wavelength conversion film includes at least one recess which passes through the wavelength conversion film, a difference in stresses and degrees thereof may be relieved by the recess even when the difference in the stresses and degrees of thermal expansion in the wavelength conversion film occurs as the number and each size of light emitting devices are increased. Accordingly, reliabilities of the wavelength conversion film and the light emitting device package are improved. In addition, since the reflective member which surrounds the side surfaces of the light emitting devices is disposed along the edge of the wavelength conversion film, light emitted from the side surfaces of the light emitting devices is prevented from leaking, and thus a performance of the light emitting devices can be improved.

The above-described light emitting device package according to the embodiment of the present invention may further include optical members, such as a light guide plate, a prism sheet, and a diffusion sheet, which serve as a backlight unit. In addition, the light emitting device package according to the embodiment may be further applied to a display device, a lighting device, and an indicating device.

Here, the display device may include a bottom cover, a reflective plate, a light emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. A backlight unit may be formed of the bottom cover, the reflective plate, the light emitting module, the light guide plate, and the optical sheet.

The reflective plate is disposed on the bottom cover, and the light emitting module emits light. The light guide plate is disposed in front of the reflective plate to guide the light emitted from the light emitting device in a forward direction, and the optical sheet including a prism sheet and the like is disposed in front of the light guide plate. The display panel is disposed in front of the optical sheet and the image signal output circuit supplies the display panel with an image signal, and the color filter is disposed in front of the display panel.

In addition, the lighting device may include a light source module having a substrate and the light emitting device package according to the embodiment, a heat dissipation unit configured to dissipate heat of the light source module, and a power supply configured to process or convert an electrical signal supplied from the outside and supply the processed or converted electrical signal to the light source module. Furthermore, the lighting device may be a lamp, a head lamp, a street lamp, or the like.

As described above, the light emitting device package of the present invention has the following effects.

First, since at least two light emitting devices share one wavelength conversion film, color uniformity and color characteristics of light emitted by the light emitting device package are improved.

Second, since a wavelength conversion film is formed with one or more recess configured to pass through the wavelength conversion film, even when the number and sizes of light emitting devices are increased and there are differences in stresses and degrees of thermal expansion in the wavelength conversion film, the differences may be relieved by the recess. Accordingly, reliability of the wavelength conversion film and the light emitting device package are improved.

Third, since a reflective member which surrounds side surfaces of light emitting devices is disposed along an edge of a wavelength conversion film, light emitted from the side surfaces of the light emitting devices is prevented from leaking, and thus a performance of the light emitting devices can be improved.

The above-described present invention is not limited to the above-described embodiments and the drawings, and it should be apparent to those skilled in the art that various substitutions, modifications, and variations are possible within a range that does not depart from the technical idea of the embodiment.

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