KR20120059061A - Light emitting device package and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A light emitting device package and a manufacturing method thereof are provided to effectively block the penetration of foreign material by protecting a fluorescent material layer and a light emitting diode through a protective film. CONSTITUTION: A light emitting diode(30) is loaded on a lead frame. A mold structure fixes the lead frame. A support structure comprises the lead frame and the mold structure. The support structure comprises an electrical connection element for connecting the light emitting diode with an external terminal. An encapsulating material(40) covers the light emitting diode. A protective film(50) is included on the encapsulating material. The protective film comprises a first protective film and a second protective film. At least, one of the first protective film and the second protective film includes grapheme.

Description

Light emitting device package and method of manufacturing the same

The present disclosure relates to a light emitting device and a method of manufacturing the same, and more particularly to a semiconductor light emitting device package and a method of manufacturing the same.

A semiconductor light emitting device such as a light emitting diode (LED) or a laser diode (LD) uses an electroluminescence phenomenon, that is, a phenomenon in which light is emitted from a semiconductor by application of a current or a voltage. As electrons and holes are combined in the active layer (ie, the light emitting layer) of the semiconductor light emitting device, energy corresponding to the energy band gap of the active layer may be emitted in the form of light.

Such a semiconductor light emitting device has a long life, can be miniaturized and reduced in weight, and has a strong directivity of light, thereby enabling low voltage driving. It is also resistant to shock and vibration, eliminating the need for warm-up time and complex drive.

In general, the light emitting device is manufactured in a package form through a process of mounting the light emitting chip in a predetermined frame and encapsulating it with a transparent resin. Functions / elements considered to be important in the light emitting device package include securing heat radiation characteristics, improving light extraction efficiency, and preventing deterioration of light emitting characteristics. Depending on the configuration and performance of the package, the life and efficiency of the light emitting device may vary.

The present invention provides a light emitting device package capable of suppressing deterioration of device characteristics due to an external environment and ensuring excellent heat dissipation characteristics and light extraction efficiency.

It provides a method of manufacturing the light emitting device package.

According to an aspect of the present invention, a light emitting chip; A support structure on which the light emitting chip is mounted and including an electrical connection element for connecting the light emitting chip to an external terminal; An encapsulant formed to cover the light emitting chip; And a protective film provided on the encapsulant and including graphene.

The support structure includes a lead frame on which the light emitting chip is mounted; And a mold structure for fixing the lead frame.

Phosphors may be provided in the passivation layer.

The passivation layer may include a first passivation layer and a second passivation layer, at least one of the first and second passivation layers may include graphene, and may include a plurality of phosphor quantum dots between the first and second passivation layers. The phosphor layer may be provided.

A graphene layer may be further provided to surround each of the plurality of phosphor quantum dots.

The phosphor may be provided in the form of a plurality of quantum dots, and the protective layer may include a graphene layer surrounding each of the quantum dots.

Phosphor may be provided in the encapsulant. In this case, the phosphor may be provided in the form of a plurality of quantum dots. A graphene layer surrounding each of the plurality of quantum dots may be further provided.

Capping layers may be further provided on the passivation layer.

The capped film may include graphene.

The protective layer may include a sheet type graphene layer.

The passivation layer may include a graphene layer having a stripe pattern.

The protective layer may include a graphene layer having a mesh structure.

It is possible to implement a light emitting device package that can effectively protect the device from the external environment and also to ensure excellent heat dissipation characteristics and light extraction efficiency.

1 is a cross-sectional view of a light emitting device package according to an embodiment of the present invention.
2 is a cross-sectional view of a light emitting device package according to another embodiment of the present invention.
3 is a cross-sectional view of a light emitting device package according to another embodiment of the present invention.
4 is a cross-sectional view of a light emitting device package according to another embodiment of the present invention.
5A to 5C are plan views illustrating various structures of a protective film (graphene layer) used in a light emitting device package according to an exemplary embodiment of the present invention.
6A through 6F are cross-sectional views illustrating a method of manufacturing a light emitting device package according to an exemplary embodiment of the present invention.
Description of the Related Art [0002]
10 lead frame 20 mold structure
30: light emitting chip 31, 32: bonding wire
40: encapsulant 50, 50 ', 50 ": protective film
55 phosphor layer 60 capping film
G1? G3: Graphene QD1: Phosphor Quantum Dot

Hereinafter, a light emitting device package and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the layers or regions illustrated in the drawings are somewhat exaggerated for clarity. Like numbers refer to like elements throughout.

1 is a cross-sectional view showing a light emitting device package according to an embodiment of the present invention.

Referring to FIG. 1, a lead frame 10 and a mold structure 20 for fixing the lead frame 10 may be provided. The lead frame 10 may be manufactured by processing a plate of metal material such as aluminum, copper, or the like by pressing, etching, or the like. The mold structure 20 may be formed of, for example, an insulating polymer, and may be formed to be coupled to the lead frame 10 by a process such as injection molding. The mold structure 20 may be formed as a structure having a groove area exposing a part of the upper surface of the lead frame 10 (a kind of cup structure).

A light emitting chip 30 may be mounted on the exposed upper surface of the lead frame 10. The light emitting chip 30 may be, for example, a light emitting diode (LED) chip. In this case, the light emitting chip 30 may include first and second semiconductor layers and an active layer (light emitting layer) provided therebetween, and emit various colors according to the physical properties of the semiconductor constituting the active layer. Although the case where the light emitting chip 30 is an LED chip has been described herein, the present invention is not limited thereto. For example, the light emitting chip 30 may be a laser diode (LD) chip, a UV photodiode chip, or an organic light emitting diode chip.

At least one bonding wire 31 and 32 may be provided to connect the light emitting chip 30 to the lead frame 10. The number of bonding wires 31 and 32 and the connection relationship between the bonding wires 31 and 32 and the lead frame 10 are exemplary and may be variously modified. The light emitting chip 30 may be electrically connected to an external terminal (not shown) by the lead frame 10 and the bonding wires 31 and 32. Therefore, the lead frame 10 and the bonding wires 31 and 32 may be referred to as electrical connection elements for electrically connecting the light emitting chip 30 to an external terminal.

An encapsulant 40 covering the light emitting chip 30 may be provided. The encapsulant 40 may be formed to fill a groove area of the mold structure 20. The encapsulant 40 may be formed of, for example, a transparent resin. For example, the encapsulant 40 may include a silicone-based resin.

A passivation layer 50 including graphene may be provided on the encapsulant 40 and the mold structure 20. The phosphor layer 55 including the plurality of phosphor quantum dots QD1 may be provided in the passivation layer 50. In detail, the passivation layer 50 may include first and second passivation layers 50a and 50b, and the phosphor layer 55 may be provided between the passivation layers 50a and 50b. At least one of the first and second passivation layers 50a and 50b may be configured to include graphene. For example, both of the first and second passivation layers 50a and 50b may be graphene layers.

Graphene is a hexagonal monolayer structure composed of carbon atoms, which is structurally / chemically stable and may exhibit excellent electrical / optical properties. Graphene is electrically two-dimensional ballistic transport. The transfer of charge in a material by two-dimensional ballistics means that it moves in a state where there is little resistance from scattering. Therefore, graphene can have very small electrical resistance and high charge mobility even at the small size of sub-micron. Graphene also has very good thermal conductivity and thermal stability. Specifically, the graphene may have a thermal conductivity of 5 × 10 ³ W / mk or more, and may stably maintain characteristics even at a high temperature of 1000 ° C. or more. Thus, graphene may have excellent heat dissipation. In addition, graphene has excellent light transmittance. Even in the case where about 10 layers of graphene are stacked, a good light transmittance similar to that of one graphene may be exhibited. In addition, graphene may serve to effectively block the penetration of foreign substances such as oxygen and moisture. In more detail, since graphene has a structure in which each electron atom is surrounded by an electron cloud, graphene may serve as a barrier to block penetration of an external material such as oxygen or moisture.

Due to the characteristics of the graphene as described above, the protective film 50 including the graphene not only serves to effectively block the penetration of external materials such as oxygen or moisture, it may also serve to improve the heat radiation characteristics. Therefore, deterioration of the characteristics of the phosphor layer 55 due to oxygen or moisture can be suppressed, and problems caused by the temperature rise of the package can be suppressed. Typical light emitting device packages may be vulnerable to moisture and high temperature. In particular, when driven under high temperature / high humidity conditions, there may be a problem such that the characteristics of the phosphor are easily deteriorated due to the penetration of oxygen or moisture, and the emission wavelength is changed. However, in the embodiment of the present invention, by protecting the phosphor layer 55 and the light emitting chip 30 using the protective film 50 including graphene, the above problems can be suppressed (or minimized). In addition, since the protective film 50 including graphene has excellent light transmittance, it may play a role of increasing light extraction efficiency.

A capping layer 60 may be further provided on the passivation layer 50. The capping layer 60 may be a kind of additional protective layer or barrier layer. The capping layer 60 may be formed to include graphene, similarly to the passivation layer 50. When the capping layer 60 includes graphene, the oxygen / moisture blocking effect and the heat radiating effect may be further improved.

The structure of FIG. 1 can be variously modified. One example is shown in FIG.

Referring to FIG. 2, a plurality of phosphor quantum dots QD1 may be provided to have a layer structure, and a passivation layer 50 ′ may be provided to surround each of the plurality of phosphor quantum dots QD1. The passivation layer 50 ′ may include graphene. For example, the passivation layer 50 ′ may be a graphene layer surrounding each of the quantum dots QD1. As such, when each of the quantum dots QD1 is surrounded by the protective film 50 ′ including graphene, each of the quantum dots QD1 may be more reliably protected from oxygen and moisture.

Although the above embodiment is related to the case where the phosphor quantum dot QD1 is provided on the encapsulant 40, in another embodiment of the present invention, the phosphor quantum dot QD1 may be provided in the encapsulant 40. Examples are shown in FIGS. 3 and 4.

Referring to FIG. 3, a plurality of phosphor quantum dots QD1 may be provided in the encapsulant 40. A protective film 50 "including graphene may be provided on the encapsulant 40. Here, the protective film 50" may be formed of the first protective film 50a or the second protective film 50b described with reference to FIG. May be similar.

FIG. 4 is modified from FIG. 3. In FIG. 4, each of the plurality of phosphor quantum dots QD1 may have a structure surrounded by the graphene layer 5. The graphene layer 5 may serve to protect the phosphor quantum dot QD1. The structure of FIG. 4 may be the same as that of FIG. 3 except that the phosphor quantum dot QD1 is surrounded by the graphene layer 5.

At least two of the structures of FIGS. 1 to 4 may be mixed to form one package. For example, in the structure of FIG. 1, each of the phosphor quantum dots QD1 may be surrounded by a separate protective film. In this case, the separate passivation layer may include graphene. In addition, various modification structures are possible.

Hereinafter, various planar structures of the passivation layer (graphene layer) that can be used in the light emitting device package according to the embodiment of the present invention will be described with reference to FIG. 5. That is, FIGS. 5A to 5C illustrate various planar structures that the passivation layers 50a, 50b, and 50 ″ of FIGS. 1, 3, and 4 may have.

Referring to FIG. 5A, the passivation layer 50A may include a sheet-type graphene layer G1. Here, the graphene layer G1 may include one or a plurality of graphenes.

Referring to FIG. 5B, the passivation layer 50B may include a graphene layer G2 patterned to have a stripe pattern. The pattern of the graphene layer G2 may have a nano size, and the gap therebetween may also be nanoscale. Such graphene layer (G2) may be referred to as graphene nanoribbons (nanoribbon).

Referring to FIG. 5C, the passivation layer 50C may include a graphene layer G3 having a mesh structure. For example, a plurality of nano holes h1 may be regularly formed in the graphene layer G3.

Although the structures of FIGS. 5A to 5C can be used individually, at least two of them may be combined to form one protective film (graphene layer). As in FIGS. 5B and 5C, even when the protective films 50B and 50C are patterned, since the capping layer 60 of FIGS. 1 to 4 is used, the phosphors are capped by the capping layer 60. The layer 55 and the light emitting chip 30 may be protected.

Hereinafter, a method of manufacturing a light emitting device package according to an embodiment of the present invention will be described with reference to FIGS. 6A to 6F.

Referring to FIG. 6A, a lead frame 10 may be formed. The lead frame 10 can be formed by processing a plate of metal material such as aluminum, copper, or the like by using press working, etching processing, or the like. The structure of the lead frame 10 is exemplary and may be variously modified.

Referring to FIG. 6B, a mold structure 20 for fixing the lead frame 10 may be formed. The mold structure 20 may be formed to be coupled to the lead frame 10 by a process such as injection molding. The lead frame 10 may be formed of an insulating polymer, for example. The mold structure 20 may be formed to have a groove area exposing a portion of the upper surface of the lead frame 10.

Referring to FIG. 6C, the light emitting chip 30 may be mounted on the exposed upper surface of the lead frame 10. At least one bonding wire 31 and 32 may be formed to electrically connect the light emitting chip 30 and the lead frame 10. Next, an encapsulant 40 covering the light emitting chip 30 may be formed in a groove region of the mold structure 20. The encapsulant 40 may be formed of, for example, a transparent resin. The transparent resin may be a silicone-based resin, but may not be.

Referring to FIG. 6D, a first passivation layer 50a may be formed on the encapsulant 40 and the mold structure 20. The first passivation layer 50a may be formed to include graphene. For example, the first passivation layer 50a may be a graphene layer. In this case, the graphene layer may be formed by a thermal chemical vapor deposition method. Thermal CVD is a relatively inexpensive process that is widely used in the manufacture of semiconductor devices. Therefore, when the first protective film 50a is formed of graphene, it can be easily formed by a low cost process.

Referring to FIG. 6E, the phosphor layer 55 including the plurality of phosphor quantum dots QD1 may be formed on the first passivation layer 50a. The phosphor layer 55 may be formed using a colloidal solution including quantum dots, or may be formed by a self-assembly method. Next, a second passivation layer 50b may be formed on the phosphor layer 55. The second protective film 50b may be formed to include graphene similarly to the first protective film 50a. In this case, the second passivation layer 50b may be formed to fill the space between the phosphor quantum dots QD1.

Referring to FIG. 6F, a capping layer 60 may be formed on the second passivation layer 50b. The capping layer 60 may be a kind of additional protective layer or barrier layer. The capping film 60 may be formed to include graphene, similarly to the protective films 50a and 50b.

As described above, according to the embodiment of the present invention, a light emitting device package having excellent heat dissipation characteristics and protection functions and excellent light extraction efficiency at a relatively easy process and low cost can be manufactured.

6A to 6F described above are related to the method of manufacturing the light emitting device package of FIG. 1, but by modifying the above, the light emitting device package of FIGS. For example, using a mixed solution in which a solution containing a phosphor quantum dot and a solution containing graphene are mixed, a structure in which each phosphor quantum dot is wrapped with graphene can be obtained, and the structure of FIGS. 2 and 4 can be obtained using the mixed solution. Can be. In addition, the manufacturing method can be modified in various ways.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, those skilled in the art will appreciate that the light emitting device package and the method of manufacturing the same according to the embodiment of the present invention may be variously modified. As a specific example, it will be appreciated that the structure of the lead frame 10 and the mold structure 20 in the light emitting device package according to the embodiment of the present invention may be variously modified. It will also be appreciated that instead of using at least one of the lead frame 10 and the mold structure 20, other elements of similar use may be used instead. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

Claims (14)

Light emitting chip;
A support structure on which the light emitting chip is mounted and including an electrical connection element for connecting the light emitting chip to an external terminal;
An encapsulant formed to cover the light emitting chip; And
And a protective film provided on the encapsulant and including graphene. The method of claim 1, wherein the support structure,
A lead frame on which the light emitting chip is mounted; And
And a mold structure for fixing the lead frame. The method of claim 1,
A light emitting device package provided with a phosphor in the protective film. The method of claim 3, wherein
The passivation layer includes a first passivation layer and a second passivation layer, at least one of the first and second passivation layers includes graphene,
A light emitting device package comprising a phosphor layer composed of a plurality of phosphor quantum dots between the first and second protective film. The method of claim 4, wherein
The light emitting device package further comprises a graphene layer surrounding each of the plurality of phosphor quantum dots. The method of claim 3, wherein
The phosphor is provided in the form of a plurality of quantum dots,
The passivation layer is a light emitting device package including a graphene layer surrounding each of the quantum dots. The method of claim 1,
A light emitting device package provided with a phosphor in the encapsulant. The method of claim 7, wherein
The phosphor is a light emitting device package provided in the form of a plurality of quantum dots. The method of claim 8,
A light emitting device package further comprising a graphene layer surrounding each of the plurality of quantum dots. The method of claim 1,
The light emitting device package further comprises a cappoxide film provided on the protective film. 11. The method of claim 10,
The capped film is a light emitting device package containing graphene. The method of claim 1,
The protective film is a light emitting device package including a sheet (graph) type of graphene layer. The method of claim 1,
The passivation layer is a light emitting device package including a graphene layer having a stripe pattern (stripe pattern). The method of claim 1,
The protective film is a light emitting device package including a graphene layer of a mesh (mesh) structure.

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