KR20150037217A - Light emitting device and method of fabricating the same - Google Patents

Abstract

Disclosed is a light emitting device having excellent heat radiation and thinness, and capable of ameliorating color difference. The disclosed light emitting device comprises: a frame having an accommodation hole; a light emitting diode chip located in the accommodation hole; an encapsulation unit located between the light emitting diode chip and the frame; and a wavelength conversion layer located on the light emitting diode chip. Therefore, the present invention has excellent thinness and heat radiation, and can ameliorate the color difference.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a light emitting device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device and a manufacturing method which are excellent in thinness and heat radiation as well as capable of improving color deviation.

Generally, a gallium nitride based light emitting diode chip is fabricated by growing gallium nitride based semiconductor layers on a sapphire substrate.

A typical light emitting diode package has a structure in which the light emitting diode chip is electrically connected to a lead frame to which an external driving signal is supplied, and the lead frame has a structure coupled with an insulating housing.

However, a common light emitting diode package has difficulties in thinning due to the combination of the lead frame and the insulating housing. A flip chip type light emitting diode which is flip chip bonded on a circuit board has recently been proposed to solve the problem of thinning. However, a general flip chip type light emitting diode includes a film type phosphor layer covering the entire light emitting diode for realizing white light. The same structure has a problem of large color deviation.

A problem to be solved by the present invention is to provide a light emitting device and a manufacturing method excellent in thinning and heat dissipation.

Another problem to be solved by the present invention is to provide a light emitting device and a manufacturing method capable of improving color deviation.

A light emitting device according to one embodiment of the present invention includes a frame having a receiving hole; A light emitting diode chip disposed in the receiving hole; An encapsulant positioned between the light emitting diode chip and the frame; And a wavelength conversion layer disposed on the light emitting diode chip.

The frame is made of a metal material or an insulating material with high reflectance.

The frame is spaced apart from the light emitting diode chip by the receiving hole.

The frame includes, on an inner surface of the receiving hole, a vertical portion perpendicular to the upper direction with respect to a lower surface of the frame, and an inclined portion extending from the vertical portion.

The frame has an inclined inner surface.

The sealing portion abuts the outer surface of the LED chip and the inner surface of the frame.

And the lower surface of the sealing portion is exposed to the outside.

The lower surface of the light emitting diode chip is exposed to the outside.

The wavelength conversion layer extends to the upper surface of the sealing portion.

The edge of the wavelength conversion layer is in contact with the inner surface of the frame.

The wavelength conversion layer includes a first wavelength conversion layer and a second wavelength conversion layer, and the first and second wavelength conversion layers include phosphors that convert light of different wavelengths.

According to another aspect of the present invention, there is provided a method of manufacturing a light emitting device, comprising: aligning a frame having a plurality of receiving holes on a substrate; aligning the LED chips in the plurality of receiving holes; Forming an encapsulating portion in the receiving hole; Forming a wavelength conversion layer in the receiving hole; And removing the substrate.

And cutting the frame before and after the step of removing the substrate and separating the frame into an appropriate light emitting device.

The step of forming the encapsulation part further includes the step of semi-curing the encapsulation part.

The forming of the wavelength conversion layer may include: forming a first wavelength conversion layer including a first phosphor; And forming a second wavelength conversion layer including a second phosphor that converts light of a wavelength band different from that of the first fluorescent material.

The step of forming the first wavelength conversion layer further includes a step of semi-curing.

The forming of the second wavelength conversion layer includes curing the second wavelength conversion layer on the semi-cured first wavelength conversion layer.

The light emitting device according to an embodiment of the present invention is advantageous in heat radiation since it is exposed on the lower surface of the LED chip and is directly mounted on the circuit board. The light emitting device has a flip chip structure LED The color variation of a general flip chip type light emitting device covering the phosphor can be improved.

Further, the light emitting device of the present invention has an advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light source module that uses a wire by flip bonding or SMT directly on a circuit board.

Moreover, the light emitting device of the present invention has an advantage in that it is thin in comparison with a light emitting device having a general lead frame.

1 is a perspective view illustrating a light emitting device according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a light emitting device cut along a line I-I 'in FIG.
FIG. 3 (a) is a plan view illustrating the structure of the light emitting diode chip of FIG. 1, and FIG. 3 (b) is a cross-sectional view of the light emitting diode chip taken along line II-II 'of FIG. 3a.
4 to 7 are views illustrating a method of manufacturing a light emitting device according to an embodiment of the present invention.
8 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the shapes of components and the like can be exaggeratedly expressed. Like reference numerals designate like elements throughout the specification. Modifications of the components that do not depart from the technical scope of the present invention are not limited thereto and can be defined only by the description of the claims in order to clearly describe the technical idea of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

FIG. 1 is a perspective view illustrating a light emitting device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a light emitting device cut along the line I-I 'of FIG.

1 and 2, a light emitting device 100 according to an exemplary embodiment of the present invention includes a frame 150, a light emitting diode chip 110, an encapsulation unit 120, and a wavelength conversion layer 130 .

The frame 150 includes a receiving hole, and an inner surface of the frame 150 by the receiving hole has a vertical portion 153 and a sloped inclined portion 151 that are perpendicular to the upper direction with respect to the lower surface . The inclined portion 151 extends along the receiving hole from the lower surface of the frame 150 and the vertical portion 153 extends from the inclined portion 151. The present invention is limited to the frame 150 having the vertical portion 153 and the inclined portion 151. However, the present invention is not limited to this, and the inner surface of the frame 150 may include either the vertical portion or the inclined portion It is possible.

The frame 150 is made of a material having high reflectance. For example, the frame 150 may be made of a white insulating resin or a metal material such as Al.

The light emitting diode chip 110 includes a growth substrate 111 and a semiconductor stacking unit 113. The light emitting diode chip 110 is exposed on the lower surface of the circuit board (not shown) with electrode pads 37a and 37b directly flip-bonded or SMT (Surface Mount Technology). Therefore, the light emitting device 100 of the present invention adopts the flip chip or the SMT light emitting diode chip 110, so that the color deviation and the luminance unevenness phenomenon are eliminated compared with the light emitting diode chip using the bonding wire, The process can be simplified.

The sealing part 120 is positioned between the light emitting diode chip 110 and the frame 150. The sealing portion 120 may be formed inside the receiving hole of the frame 150 by a height of the LED chip 110. The sealing part 120 has an insulating function and fixes the LED chip 110 and the frame 150 together. The sealing part 120 may be made of a transparent insulating resin and may have an upper surface parallel to the upper surface of the LED chip 110. One surface of the sealing part 120 is in contact with the outer surface of the LED chip 110 and the other surface of the sealing part 120 is in contact with the inner surface of the frame 150.

The wavelength conversion layer 130 is disposed on the light emitting diode chip 110 and the encapsulation unit 120. The wavelength conversion layer 130 is accommodated in a receiving hole of the frame 150 and covers the LED chip 110 and the encapsulation unit 120. The wavelength conversion layer 130 is in contact with the upper surface of the light emitting diode chip 110 and the encapsulation unit 120 and contacts the inner surface of the frame 150. The wavelength conversion layer 130 includes a phosphor. The phosphor may convert the wavelength of the light emitted from the LED chip 110.

Since the light emitting device 100 according to the embodiment of the present invention described above is exposed on the lower surface of the LED chip 110 and directly mounted on the circuit board, Chip type light emitting device that covers the phosphor on the flip chip structure light emitting diode by the wavelength conversion layer 130 that is formed on the surface of the light emitting diode.

In addition, the light emitting device 100 of the present invention has an advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light source module using flip bonding or SMT directly to a circuit board.

Furthermore, the light emitting device 100 of the present invention has an advantageous advantage in thinning as compared with a light emitting device having a general lead frame.

3A and 3B, the structure of the light emitting diode chip 110 will be described in more detail.

FIG. 3A is a plan view specifically showing a configuration of the light emitting diode chip of FIG. 1, and FIG. 3B is a cross-sectional view of the light emitting diode chip cut along the line I-I 'of FIG. 3A.

As shown in FIGS. 2A and 2B, the LED chip of the present invention includes a growth substrate 111 and a semiconductor stacking unit 113.

The semiconductor stacking part 113 includes a first conductivity type semiconductor layer 23 formed on the growth substrate 111 and a plurality of mesas M spaced from each other on the first conductivity type semiconductor layer 23 do.

The plurality of mesas M include an active layer 25 and a second conductivity type semiconductor layer 27, respectively. The active layer 25 is located between the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27. [ On the other hand, the reflective electrodes 30 are positioned on the plurality of mesas M, respectively.

The plurality of mesas M may have an elongated shape extending parallel to each other in one direction as illustrated. This shape simplifies the formation of a plurality of mesas M of the same shape in a plurality of chip regions on the growth substrate 111.

The reflective electrodes 30 may be formed on each of the mesas M after the plurality of mesas M are formed. However, the present invention is not limited thereto, and the second conductivity type semiconductor layer 27 may be grown, May be previously formed on the second conductivity type semiconductor layer 27 before forming the second conductivity type semiconductor layers M. The reflective electrode 30 covers most of the upper surface of the mesa M and has substantially the same shape as the planar shape of the mesa M. [

The reflective electrodes 30 may include a reflective layer 28 and may further include a barrier layer 29. The barrier layer 29 may cover the top and side surfaces of the reflective layer 28. For example, the barrier layer 29 may be formed to cover the upper surface and the side surface of the reflective layer 28 by forming a pattern of the reflective layer 28 and forming a barrier layer 29 thereon. For example, the reflective layer 28 may be formed by depositing and patterning Ag, Ag alloy, Ni / Ag, NiZn / Ag, and TiO / Ag layers. The barrier layer 29 may be formed of Ni, Cr, Ti, Pt, Rd, Ru, W, Mo, TiW or a composite layer thereof to prevent the metal material of the reflection layer from being diffused or contaminated.

After the plurality of mesas M are formed, the edges of the first conductivity type semiconductor layer 23 may also be etched. Thus, the upper surface of the growth substrate 111 can be exposed. The side surfaces of the first conductivity type semiconductor layer 23 may also be inclined.

The light emitting diode chip of the present invention further includes a lower insulating layer 31 covering the plurality of mesas M and the first conductivity type semiconductor layer 23. The lower insulating layer 31 has openings for allowing electrical connection to the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27 in a specific region. For example, the lower insulating layer 31 may have openings for exposing the first conductivity type semiconductor layer 23 and openings for exposing the reflective electrodes 30.

The openings may be located near the area between the mesas M and the edge of the substrate 21 and may have an elongated shape extending along the mesas M. [ On the other hand, the openings are located on the upper portion of the mesa M and are biased to the same end side of the mesa.

The light emitting diode chip of the present invention includes a current dispersion layer 33 formed on the lower insulating layer 31. The current spreading layer 33 covers the plurality of mesas M and the first conductivity type semiconductor layer 23. In addition, the current-spreading layer 33 has openings located in the respective upper regions of the mesa M and exposing the reflective electrodes. The current spreading layer 33 may be in ohmic contact with the first conductive semiconductor layer 23 through the openings of the lower insulating layer 31. The current spreading layer 33 is insulated from the plurality of mesas M and the reflective electrodes 30 by the lower insulating layer 31.

The openings of the current spreading layer 33 have a larger area than the openings of the lower insulating layer 31 to prevent the current spreading layer 33 from connecting to the reflective electrodes 30. [

The current spreading layer 33 is formed on almost the entire region of the substrate 31 except for the openings. Therefore, the current can be easily dispersed through the current dispersion layer 33. [ The current spreading layer 33 may include a highly reflective metal layer such as an Al layer and the highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. Further, a protective layer of a single layer or a multiple layer structure such as Ni, Cr, Au or the like may be formed on the highly reflective metal layer. The current-spreading layer 33 may have a multilayer structure of Ti / Al / Ti / Ni / Au, for example.

In the light emitting diode chip of the present invention, the upper insulating layer 35 formed on the current spreading layer 33 is formed. The upper insulating layer 35 has openings for exposing the reflective electrodes 30 together with openings for exposing the current-spreading layer 33.

The upper insulating layer 35 may be formed using an oxide insulating layer, a nitride insulating layer, a mixed layer or a cross layer of these insulating layers, or a polymer such as polyimide, Teflon, or parylene.

A first electrode pad 37a and a second electrode pad 37b are formed on the upper insulating layer 35. [ The first electrode pad 37a is connected to the current spreading layer 33 through the opening of the upper insulating layer 35 and the second electrode pad 37b is connected to the reflective electrodes 30). The first electrode pad 37a and the second electrode pad 37b may be used as a pad for connecting a bump or a pad for SMT to mount a light emitting diode on a circuit board or the like.

The first and second electrode pads 37a and 37b may be formed together in the same process and may be formed using, for example, a photo and etch technique or a lift-off technique. The first and second electrode pads 37a and 37b may include an adhesive layer of, for example, Ti, Cr, Ni, or the like and a high-conductivity metal layer of Al, Cu, Ag, or Au. The first and second electrode pads 37a and 37b may be formed so that their end portions are located on the same plane, so that the light emitting diode chip can be flip-bonded onto a conductive pattern formed at the same height on the circuit board.

Thereafter, the light-emitting diode chip is completed by dividing the growth substrate 111 into individual light-emitting diode chip units. The growth substrate 111 may be removed from the light emitting diode chip before or after being divided into individual light emitting diode chip units.

As described above, the LED chip of the present invention, which is directly flip-bonded to the circuit board, has the advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light emitting device.

4 to 7 are views illustrating a method of manufacturing a light emitting device according to an embodiment of the present invention.

Referring to FIG. 4, a first step of manufacturing a light emitting device according to an embodiment of the present invention includes aligning a frame 150 having a receiving hole 155 on a substrate 101. Although a frame 150 having one receiving hole 155 is shown in the drawing, a frame 150 having a plurality of receiving holes 155 is provided on the substrate 101 for mass production in an actual manufacturing process .

The frame 150 includes a vertical portion 153 vertical to the upper direction with respect to the lower surface of the frame 150 along the inner side and an inclined portion 151 extended from the vertical portion 153 do.

Referring to FIG. 5, in the second step, the light emitting diode chip 110 is aligned on the substrate 101 in the receiving hole 155. The light emitting diode chip 110 includes a growth substrate 111 and a semiconductor stacking unit 113. The detailed structure of the light emitting diode chip 110 will be described with reference to FIGS. 1 to 3, and a detailed description thereof will be omitted.

Referring to FIG. 6, in the third step, an encapsulating portion 120 is formed between the LED chip 110 and the frame 150. The encapsulation part 120 is in contact with the outer surfaces of the light emitting diode chip 110. The third step includes a semi-curing step of the sealing part 120.

Referring to FIG. 7, in the fourth step, the wavelength conversion layer 130 is formed on the LED chip 110 and the encapsulation unit 120. The wavelength conversion layer 130 covers the upper surface of the light emitting diode chip 110 and the upper surface of the sealing portion 120. The wavelength conversion layer 130 includes a phosphor. The fourth step further includes separating the substrate 101.

Here, the process of separating the frame 150 into unit light emitting devices may be performed before or after the substrate 101 is separated.

The light emitting device according to an embodiment of the present invention described above is exposed to the lower surface of the LED chip 110 and directly mounted on the circuit board, The layer 130 can improve the color deviation of the general flip chip type light emitting device covering the phosphor on the flip chip structure light emitting diode.

Further, the light emitting device of the present invention has an advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light source module that uses a wire by flip bonding or SMT directly on a circuit board.

Moreover, the light emitting device of the present invention has an advantage in that it is thin in comparison with a light emitting device having a general lead frame.

8 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.

8, the light emitting device 200 according to another embodiment of the present invention is the same as the light emitting device 100 of FIG. 1 except for the wavelength conversion layer 230 according to an embodiment of the present invention Structures other than the wavelength conversion layer 230 are denoted by the same reference numerals, and a detailed description thereof will be omitted.

The wavelength conversion layer 230 includes a first wavelength conversion layer 231 covering the light emitting diode chip 110 and the encapsulation unit 120 and a second wavelength conversion layer 233 covering the first wavelength conversion layer 231, .

The first and second wavelength conversion layers 231 and 233 include phosphors that convert light of different wavelengths. For example, when the light emitting diode chip 110 is a blue chip emitting blue light, the first wavelength conversion layer 231 includes a red phosphor for converting red wavelength light, and the second wavelength conversion layer 233, May include a green phosphor that converts light in the green wavelength range.

The light emitting device 200 according to another embodiment of the present invention includes the first and second wavelength conversion layers 231 and 233 including phosphors different from each other to thereby allow the user to control light of a desired wavelength range .

The method of manufacturing the light emitting device 200 according to another embodiment of the present invention includes the steps of semi-curing the first wavelength conversion layer 231 on the LED chip 110 and then forming the second wavelength conversion layer 233 Can be formed on the first wavelength conversion layer (231).

Since the light emitting device 200 according to another embodiment of the present invention is exposed to the lower surface of the light emitting diode chip 110 and directly mounted on the circuit board, The color variation of the general flip chip type light emitting device covering the phosphor on the flip chip structure light emitting diode can be improved.

In addition, the light emitting device 200 of the present invention has an advantage of being able to realize high efficiency and miniaturization in comparison with a general package type light source module that uses a wire by flip bonding or SMT directly on a circuit board.

Furthermore, the light emitting device 200 of the present invention has an advantage in thinning compared to a light emitting device having a general lead frame.

Although various embodiments have been described above, the present invention is not limited to the specific embodiments. In addition, the elements described in the specific embodiments may be applied to the same or similar elements in other embodiments without departing from the spirit of the present invention.

100, 200: light emitting device 110: light emitting diode chip
120: encapsulant 130, 230: wavelength conversion layer
150: frame

Claims (17)

A frame having a receiving hole;
A light emitting diode chip disposed in the receiving hole;
An encapsulant positioned between the light emitting diode chip and the frame; And
And a wavelength conversion layer disposed on the light emitting diode chip. The method according to claim 1,
Wherein the frame is made of a metal material or an insulating material having a high reflectance. The method according to claim 1,
Wherein the frame is spaced apart from the light emitting diode chip by the receiving hole. The method according to claim 1,
Wherein the frame includes a vertical portion on an inner surface of the receiving hole, the vertical portion being vertically upward with respect to a lower surface of the frame, and the inclined portion extending from the vertical portion. The method according to claim 1,
Wherein the frame has an inclined inner surface. The method according to claim 1,
Wherein the sealing portion is in contact with an outer surface of the LED chip and an inner surface of the frame. The method according to claim 1,
And the lower surface of the sealing portion is exposed to the outside. The method according to claim 1,
And the lower surface of the light emitting diode chip is exposed to the outside. The method according to claim 1,
Wherein the wavelength conversion layer extends to an upper surface of the sealing portion. The method according to claim 1,
And an edge of the wavelength conversion layer is in contact with an inner surface of the frame. The method according to claim 1,
Wherein the wavelength conversion layer includes first and second wavelength conversion layers, and the first and second wavelength conversion layers include phosphors that convert light of different wavelengths. Aligning a frame having a plurality of receiving holes on the substrate, and aligning the LED chips in the plurality of receiving holes;
Forming an encapsulating portion in the receiving hole;
Forming a wavelength conversion layer in the receiving hole; And
And removing the substrate. The method of claim 12,
Cutting the frame before and after the step of removing the substrate and separating the frame into an appropriate light emitting device. The method of claim 12,
Wherein the step of forming the encapsulation part further comprises semi-curing the encapsulation part. The method of claim 12,
Wherein the forming the wavelength conversion layer comprises:
Forming a first wavelength conversion layer including a first phosphor; And
And forming a second wavelength conversion layer including a second phosphor for converting light of a wavelength band different from that of the first fluorescent material. 16. The method of claim 15,
Wherein the step of forming the first wavelength conversion layer further comprises the step of semi-curing. 18. The method of claim 16,
Wherein the forming the second wavelength conversion layer comprises curing the second wavelength conversion layer on the semi-cured first wavelength conversion layer.

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