KR20070063976A - Light emitting device of flip chip structure and manufacturing method thereof - Google Patents

Abstract

The present invention provides a light emitting cell block including a light emitting cell including an n-type semiconductor layer and a p-type semiconductor layer on one surface of a base substrate, a sub-mount substrate on which the light-emitting cell block is flip chip bonded, and between the light-emitting cell block and the sub-mount substrate. And an underfill resin layer filled in a space of the underfill resin layer, wherein the underfill resin layer includes reflective particles that diffusely reflect light from the semiconductor layer. The reflective particles are characterized in that it comprises Al, Ag or AlN.

The present invention forms an underfill resin layer using a resin containing reflective particles diffusely reflecting light emitted from a light emitting layer, thereby preventing light from being absorbed and smoothly reflecting light, thereby having high luminance and luminous efficiency, and uniformizing light of a light emitting device. There is an advantage that can be released easily.

Description

Flip chip light emitting device and method for manufacturing the same {Flip chip Light-emitting device and Method of manufacturing the same}

1 is a conceptual cross-sectional view for explaining a light emitting device having a conventional general flip chip structure.

2 is a conceptual diagram illustrating a general underfill process.

3 is a conceptual cross-sectional view for explaining a light emitting device according to the present invention;

4A to 4F are cross-sectional views illustrating a manufacturing process of the first embodiment according to the present invention.

5A to 5E are cross-sectional views illustrating a manufacturing process of the second embodiment according to the present invention.

<Explanation of symbols for the main parts of the drawings>

20, 25: base substrate 30: n-type semiconductor layer

40: active layer 50: p-type semiconductor layer

60, 65: metal bump 70: underfill resin layer

75: reflective particles 80: insulating layer

90 wiring 100 light emitting cell block

200: sub-mount substrate 210: substrate

220, 225: bonding pad 230: electrode layer

240: bonding layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device having a flip-chip structure and a method of manufacturing the same. More particularly, the present invention relates to a light emitting device capable of protecting the light emitting device from the outside by using an underfill technology and a method of manufacturing the same. It is about.

A light emitting diode (LED) refers to a device that makes a small number of carriers (electrons or holes) injected using a pn junction structure of a semiconductor and emits a predetermined light by recombination thereof. GaAs, AlGaAs, GaN Various colors may be realized by configuring a light emitting source by changing a compound semiconductor material such as InGaN, AlGaInP, or the like.

Such a light emitting device has a smaller power consumption and a longer life than conventional light bulbs or fluorescent lamps, can be installed in a narrow space, and exhibits strong vibration resistance. These light emitting devices are used as display devices and backlights, and because they have excellent characteristics in terms of power consumption reduction and durability, they are expected to be widely applied to general lighting, large LCD-TV backlights, automotive headlights, and general lighting. For this purpose, the light emission efficiency of the light emitting device needs to be improved, the heat dissipation problem must be solved, and the high brightness and high power of the light emitting device must be achieved.

In order to solve this problem, the interest in flip-chip type semiconductor light emitting devices is increasing day by day.

1 is a conceptual cross-sectional view illustrating a light emitting device having a conventional general flip chip structure, in which an n-type semiconductor layer 5, an active layer 6, and a p-type semiconductor layer 7 are sequentially formed on a predetermined substrate 1. The formed light emitting cell is flip-chip bonded to a separate sub-mount substrate 2 to produce a light emitting device. At this time, the p-type semiconductor layer 7 and n of the light emitting cell are connected to the first and second electrodes 3 and 4 of the sub-mount substrate 2 through the p-type solder 8 and the n-type solder 9. The type semiconductor layer 5 is bonded.

The light emitting device of the flip chip structure has a high heat dissipation efficiency than the conventional light emitting device, and there is almost no light shielding, so that the light efficiency is increased by more than 50% compared to the conventional light emitting device.

In general, in the technique of flip chip mounting of a semiconductor device, an underfill technique for filling a resin member between a semiconductor chip and a substrate is known. That is, as illustrated in FIG. 2, the semiconductor chip 11 is mounted on the substrate 12 by face-down, and the chip 11 and the substrate bumped by the solder 13 using the dispenser 14 are used. (12) The liver is filled with the resin member 15. As a result, the solder 13 and the connecting portion connecting the chip 11 and the substrate 12 are protected by the resin 15.

Korean Patent Laid-Open Publication No. 2004-0083897 discloses a flip chip package method capable of rapidly processing a process by adding ultrasonic waves to thermocompression in flip chip bonding, and a packaging structure of a light emitting diode using the same. In particular, a light emitting diode package using the aforementioned underfill technology is already disclosed by filling a connection space between the LED chip and the substrate with a resin in a substrate where the LED chip is bonded in a flip chip bonding step.

However, in the light emitting device having such a structure, a large amount of photons generated in the light emitting layer is absorbed and disappeared inside the underfill resin layer. That is, since the light emitted from the light emitting layer is absorbed and extinguished by the underfill resin layer surrounding the light emitting layer, the light output does not easily escape to the outside of the light emitting device.

The present invention is to solve the above problems, by using an underfill technology to protect the bonding portion of the light emitting cell block and the sub-mount substrate from the outside and to reduce the thermal expansion deformation caused by the heat of the light emitting device to improve the reliability And it aims to provide the manufacturing method thereof.

Another object of the present invention is to form an underfill resin layer using a resin containing reflective particles diffusely reflecting the light emitted from the light emitting layer, thereby preventing the absorption of light and smooth reflection of the light to have a high brightness and luminous efficiency, It is to provide a light emitting device capable of uniformly emitting light and a method of manufacturing the same.

The present invention provides a light emitting cell block in which a light emitting cell including an n-type semiconductor layer and a p-type semiconductor layer is formed on one surface of a base substrate, a sub-mount substrate on which the light emitting cell block is flip chip bonded, and the light emission. An underfill resin layer filled in a space between a cell block and a sub-mount substrate, wherein the underfill resin layer includes reflective particles that diffusely reflect light from the semiconductor layer.

In the light emitting device of the present invention, a plurality of light emitting cells spaced apart from each other may be formed on one surface of the base substrate, and an n-type semiconductor layer of the one light emitting cell and a p-type semiconductor layer of another light emitting cell adjacent thereto may be connected. The electronic device may further include wiring for connecting the n-type semiconductor layer of one light emitting cell and the p-type semiconductor layer of another light emitting cell adjacent thereto.

The reflective particles may include Al, Ag or AlN. The reflective particles are spherical or rectangular in shape, and preferably have a size of 0.1 to 100 µm.

In addition, an insulating layer may be further included in an area excluding a flip chip bonded portion of the light emitting cell block.

The present invention provides a light emitting cell block by forming an n-type semiconductor layer and a p-type semiconductor layer on an upper surface of a base substrate, flip chip bonding the light emitting cell block on a separate sub-mount substrate, and the light emitting cell block; It provides a method for manufacturing a light emitting device comprising the step of filling the space between the sub-mount substrate with a resin containing reflective particles to form an underfill resin layer.

The preparing of the light emitting cell block may include removing a portion of the n-type semiconductor layer and a p-type semiconductor layer to form a plurality of light emitting cells, and forming an n-type semiconductor layer of one light emitting cell and another adjacent one through the bridge wiring. The method may further include connecting a p-type semiconductor layer of one light emitting cell, and the bridge wiring may be connected to another n-type semiconductor layer of one light emitting cell through a bridge process or a step cover process. The p-type semiconductor layer of one light emitting cell may be connected.

Hereinafter, a light emitting device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

3 is a conceptual cross-sectional view for describing a light emitting device according to the present invention.

Referring to the drawings, the light emitting device includes a light emitting layer on the base substrate 20, that is, an n-type semiconductor layer 30, an active layer 40, and a p-type semiconductor layer 50 sequentially formed, and the base substrate 20. ) And a submount substrate that is flip chip bonded. The sub-mount substrate may include a p-type semiconductor layer 50, an n-type semiconductor layer 30 of the emission layer, a p-type bonding pad 220 to be bonded thereto, and an n-type bonding pad 225 on a separate substrate 210. The light emitting layer is connected to the bonding pads 220 and 225 of the sub-mount substrate using metal bumps 60 and 65.

The light emitting device of the present invention also includes an underfill resin layer 70 filled with a resin including reflective particles 75 diffusely reflecting light from the light emitting layer in a space between the base substrate 20 on which the light emitting layer is formed and the sub-mount substrate. ). The reflective particles 75 diffusely reflect the light emitted from the light emitting layer and emit the light to the outside without absorbing the light. To this end, the reflective particles 75 preferably contain 10% or more of a material having a reflectance of 50% or more with respect to light. The reflective particles 75 may be formed in various shapes, including spherical or rectangular, and may be formed in a size of 0.1 to 100 μm. The reflective particles 75 may include Al, Ag, or AlN. In addition, the reflective particles 75 are preferably nanoparticles for efficient diffuse reflection.

The light emitting device of the present invention uses underfill technology to fill the space between the base substrate and the sub-mount substrate on which the light emitting layer is formed with a resin, thereby protecting from physical or chemical external environment as well as thermal expansion deformation due to temperature change. Since it also serves as a reinforcing material for, it is possible to improve the reliability of the light emitting device and to extend its life.

In addition, in the light emitting device of the present invention, light emitted from the light emitting layer is not absorbed and extinguished in the underfill resin layer, and is diffusely reflected by the reflective particles included in the underfill resin layer to escape to the outside, thereby obtaining improved light emission efficiency. In addition, since the reflective particles uniformly distributed in the underfill resin layer diffuse widely the light emitted from the light emitting layer, light can be uniformly emitted in a wide range without forming unnecessary light emitting patterns.

4A to 4F are cross-sectional views illustrating a manufacturing process of the first embodiment according to the present invention.

Referring to FIG. 4A, a light emitting layer, that is, an n-type semiconductor layer 30, an active layer 40, and a p-type semiconductor layer 50 are sequentially formed on the base substrate 20.

The base substrate 20 refers to a general wafer for manufacturing a light emitting device, and a transparent substrate such as Al ₂ O ₃ , ZnO, LiAl ₂ O _3, or the like is used. In this embodiment, a sapphire substrate is used. Before the n-type semiconductor layer 30 is formed on the base substrate 20, a buffer layer (not shown) including AlN or GaN may be formed to reduce the lattice mismatch with the sapphire substrate.

The n-type semiconductor layer 30 is a layer in which electrons are generated, preferably using gallium nitride (GaN) implanted with n-type impurities, and the material layer having various semiconductor properties is not limited thereto. In this embodiment, an n-type semiconductor layer 30 including n-type Al _x Ga _{1 - x} N (0 ≦ _x ≦ ₁ ) is formed. In addition, the p-type semiconductor layer 50 is a layer in which holes are generated, preferably using gallium nitride (GaN) implanted with p-type impurities, and not limited thereto, and may be a material layer having various semiconductor properties. In this embodiment, a p-type semiconductor layer 50 including p-type Al _x Ga _{1 - x} N (0 ≦ _x ≦ ₁ ) is formed. In addition, InGaN may be used as the semiconductor layer. The n-type semiconductor layer 30 and the p-type semiconductor layer 50 may be formed of a multilayer film.

The active layer 40 has a predetermined band gap and is a region in which quantum wells are made to recombine electrons and holes, and may include InGaN. According to the type of material constituting the active layer 40, the emission wavelength generated by the combination of electrons and holes is changed. Therefore, it is preferable to adjust the semiconductor material contained in the active layer 40 according to the target wavelength.

The above-described material layers may include metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), plasma chemical vapor deposition (PCVD), molecular beam growth (MBE), and molecular beam growth (MBE). It is formed through various deposition and growth methods including beam epitaxy) and hydride vapor phase epitaxy (HVPE).

Thereafter, as shown in FIG. 4B, a portion of the p-type semiconductor layer 50, the active layer 40, and the n-type semiconductor layer 30 are removed through a predetermined etching process to separate light emitting cells. A portion of the n-type semiconductor layer 30 is exposed by removing a portion of the p-type semiconductor layer 50 and the active layer 40 through a predetermined etching process.

This is not limited to the above, and may be variously changed for convenience of process. That is, a portion of the n-type semiconductor layer 30 is exposed by first removing a portion of the p-type semiconductor layer 50 and the active layer 40, and then exposing the n-type semiconductor layer 30 to form a plurality of light emitting cells. The predetermined area of) may be removed to expose the base substrate 20.

In addition, as shown in FIG. 4C, a p-type metal bump 60 is formed on the p-type semiconductor layer 50, and an n-type metal bump 65 is formed on the exposed n-type semiconductor layer 30. . As the p-type and n-type metal bumps 60 and 65, at least one of Pb, Sn, Au, Ge, Cu, Bi, Cd, Zn, Ag, Ni, and Ti may be used, and an alloy thereof may be used. have.

In addition, the insulating layer 80 is formed using an insulating material such as SiO ₂ , Si ₃ O ₄ , Al ₂ O _3, or the like except for the portions where the p-type and n-type metal bumps 60 and 65 are formed. The insulating layer 80 is preferably formed for electrical stability when the reflective particles 75 included in the underfill resin layer 70 are metal. Of course, when an insulating material such as AlN is used as the reflective particles 75 to be included in the underfill resin layer 70, the formation of the insulating layer 80 may be omitted.

As a result, the light emitting cell block 100 having a plurality of light emitting cells formed on the base substrate 20 is manufactured. The manufacturing process of the light emitting cell block 100 is not limited to the above-described method, and various modifications and various material films may be further added. For example, a reflective layer for reflecting light may be further formed on the p-type semiconductor layer 50, and the current may be smoothly supplied to the p-type semiconductor layer 50 or the exposed n-type semiconductor layer 30. In addition, a separate ohmic metal layer may be further formed. Cr and Au may be used as the ohmic metal layer. In addition, in the present embodiment, the metal bumps 60 and 65 are first formed, and then the insulating layer 80 is formed. However, the present invention is not limited thereto. After the 80 is formed, the metal bumps 60 and 65 may be formed.

Next, a submount substrate 200 as shown in FIG. 4D is prepared. The sub-mount substrate 200 includes a plurality of substrates 210 connecting the n-type semiconductor layer 30 of one light emitting cell of the light emitting cell block 100 to the p-type semiconductor layer 50 of another light emitting cell. The electrode layer 230 is included. The apparatus may further include a p-type bonding pad 220 formed at one edge and an n-type bonding pad 225 formed at the other edge.

In this case, SiC, Si, Ge, SiGe, AlN, metal, or the like having excellent thermal conductivity is used as the substrate 210. In this embodiment, AlN having excellent thermal conductivity and insulating properties is used. Of course, the present invention is not limited thereto, and a metallic material having high thermal conductivity and excellent electrical conductivity may be used. In this case, a separate insulating layer needs to be formed on the substrate 20.

The electrode layer 230, the p-type bonding pad 220, and the n-type bonding pad 225 use a metal having excellent electrical conductivity. It is formed by a screen printing method or a deposition process using a predetermined mask pattern.

Thereafter, the light emitting cell block 100 and the sub-mount substrate 200 are flip chip bonded.

4E illustrates that the light emitting cell block 100 and the sub-mount substrate 200 are bonded to each other. The p-type of one light emitting cell of the light emitting cell block 100 is bonded through the metal bumps 60 and 65. The n-type semiconductor layer 30 of another light emitting cell adjacent to the semiconductor layer 50 is bonded to be electrically connected to the metal bumps 60 and 65 through the electrode layer 230 of the sub-mount substrate 200. The p-type metal bump 60 located at one edge of the light emitting cell block 100 is connected to the p-type bonding pad 220 of the sub-mount substrate 200, and the n-type metal bump 65 located at the other edge of the light emitting cell block 100 is connected to the sub type. It is connected to the n-type bonding pad 225 of the mount substrate 200.

At this time, the bonding may be performed using heat or ultrasonic waves, or simultaneously using heat and ultrasonic waves. The connection between the metal bumps 60 and 65 and the lower bonding pads 220 and 225 is bonded through various bonding methods.

In addition, the n-type and p-type metal bumps 60 and 65 may not be formed on the light emitting cell, and the metal bumps 60 and 65 may be formed on the sub-mount substrate.

As such, after the light emitting cell block 100 and the sub-mount substrate 200 are electrically connected to each other using the metal bumps 60 and 65, the oxidation of the metal bumps 60 and 65 is prevented and the light emitting cell block 100 is prevented. And the undermount substrate 200 are underfilled to maintain the electrical connection state stably. In this case, the reflective particles including Al, Ag or AlN are mixed with a resin such as a transparent epoxy resin as a member for the underfill process. That is, in the light emitting device of the present invention, the reflective particles 75 are uniformly mixed and distributed in the underfill resin layer 70 formed between the light emitting cell block 100 and the sub-mount substrate 200. The reflective particles 75 diffusely reflect the light emitted from the light emitting layer and emit the light to the outside without absorbing light. The reflective particles 75 may have a spherical shape or a rectangular shape with a size of 0.1 to 100 μm. In addition, the reflective particles 75 are preferably nanoparticles for efficient diffuse reflection.

Referring to FIG. 4F, an underfill member in which reflective particles 75 are uniformly mixed is injected into a space between the light emitting cell block 100 and the sub-mount substrate 200, and then cured by undercuring the underfill resin layer 70. Form. In the present embodiment, the light emitting cell block 100 and the sub-mount substrate 200 are first flip chip bonded and then underfilled. However, the present invention is not limited thereto, and the reflective particles 75 may be uniformly mixed before flip chip bonding. Dispensing the liquid underfill member on the sub-mount substrate 200 and flip-chip bonding the light emitting cell block 100 on which the metal bumps 60 and 65 are formed to be electrically connected by the metal bumps 60 and 65 and underfilled. The underfill resin layer 70 may be formed by hardening the member.

Due to the underfill resin layer 70, the bonding portion of the light emitting cell block 100 and the sub-mount substrate 200 may be protected from the outside, and thermal expansion deformation due to the heat of emission of the light emitting device may be reduced to improve reliability.

In addition, the present embodiment includes reflective particles 75 inside the underfill resin layer 70, so that light from the light emitting layer collides with the reflective particles 75 and is diffusely reflected to escape to the outside, thereby obtaining improved light emission efficiency. Can be. In addition, since the reflective particles 75 uniformly distributed in the underfill resin layer 70 diffuse the light emitted from the light emitting layer widely, the light can be uniformly emitted in a wide range without forming an unnecessary light emission pattern.

As a result, a light emitting cell block including a plurality of light emitting cells is flip-chip bonded on a sub-mount substrate, and an underfill resin layer filled with a resin containing reflective particles is formed in a space between the light-emitting cell block and the sub-mount substrate. A light emitting device having a flip chip structure can be manufactured. The light emitting cells may be variously connected in series, in parallel, or in parallel and according to a desired purpose, and may be used for lighting by being driven at a proper voltage and current, and may also be driven by AC power.

In the present embodiment, the n-type semiconductor layer and the p-type semiconductor layer of adjacent light emitting cells are electrically connected to each other using metal bumps during flip chip bonding of the light emitting cell block and the sub-mount substrate.

However, the present invention is not limited thereto, and the bridge wiring electrically connecting the n-type semiconductor layer and the p-type semiconductor layer of adjacent light emitting cells through a bridge process or a step cover during manufacturing of the light emitting cell block. After the formation, the chip may be flip-chip bonded to the sub-mount substrate. On the other hand, in the second embodiment described below, a description overlapping with the case of the first embodiment will be omitted.

5A to 5E are cross-sectional views illustrating a manufacturing process of the second embodiment.

Referring to FIG. 5A, a plurality of light emitting cells in which an n-type semiconductor layer 30, an active layer 40, and a p-type semiconductor layer 50 are sequentially formed are formed on a base substrate 20.

Thereafter, the n-type semiconductor layer 30 and the p-type semiconductor layer 50 between adjacent light emitting cells are connected through a predetermined wiring forming process. That is, the exposed n-type semiconductor layer 30 of one light emitting cell and the p-type semiconductor layer 50 of another light emitting cell adjacent thereto are connected to the wiring 90. In this case, the conductive wiring 90 electrically connecting the n-type semiconductor layer 30 and the p-type semiconductor layer 50 of adjacent light emitting cells through a bridge process or a step cover process. To form.

The bridge process described above is also referred to as an air bridge process, by using a photo process between the chips to be connected to each other by using a photo process to form a photoresist pattern, and then forming a material such as metal on the first thin film by a method such as vacuum deposition, Again, a conductive material containing gold is applied to a predetermined thickness by a method such as electroplating, electroplating or metal deposition. Subsequently, when the photoresist pattern is removed with a solution such as solvent, the lower portion of the conductive material is removed and only the bridge-shaped conductive material is formed in the space.

In addition, the step cover process applies a photoresist between the chips to be connected to each other by using a photo process, and develops, leaving only the portions to be connected to each other and covering the other portions with a photoresist pattern, and by electroplating, electroless plating or metal deposition thereon. A conductive material comprising gold is applied to a certain thickness. Subsequently, when the photoresist pattern is removed with a solution such as a solvent, all portions other than the conductive material are covered and only the covered portions remain to electrically connect the chips to be connected.

As the wiring 90, all materials having conductivity as well as metal may be used. For example, it can be formed from Au, Ag, Ni, Cr, Pt, Pd, Ti, W, Ta or an alloy thereof.

In addition, a plurality of metal bumps are formed on the light emitting cell, and the n-type semiconductor layer 30 of the light emitting cell positioned on the other side of the p-type semiconductor layer 50 of the light emitting cell positioned on one edge of the light emitting cell block 100. P-type metal bumps 60 and n-type metal bumps 65 are respectively formed on the N-type metal bumps.

In addition, the insulating layer 80 is formed using an insulating material such as SiO ₂ , Si ₃ O ₄ , Al ₂ O _3, or the like except for the portion where the wiring 90 and the metal bumps 60 and 65 are formed. The insulating layer 80 is preferably formed for electrical stability when the reflective particles 75 included in the underfill resin layer 70 is a metal. Of course, when an insulating material such as AlN is used as the reflective particles 75 to be included in the underfill resin layer 70, the formation of the insulating layer 80 may be omitted.

As a result, the light emitting cell block 100 having a plurality of light emitting cells formed on the base substrate 20 is manufactured. The manufacturing process of the light emitting cell block 100 is not limited to the above-described method and variously changed or various material films may be further added for convenience of process. For example, after forming the plurality of light emitting cells, a separate electrode is formed in an area where the metal bumps 60 and 65 and the wiring 90 are to be formed, and an insulating layer 80 is formed in an area except the electrode. After that, the metal bumps 60 and 65 and the wiring 90 may be formed on the electrode.

Next, a separate sub-mount substrate 200 to be bonded with the light emitting cell block 100 is prepared. Referring to FIG. 5C, the sub-mount substrate 200 includes a substrate 210 and a plurality of bonding layers 240 formed on the substrate 210. In addition, the method further includes a p-type bonding pad 220 positioned at one edge and an n-type bonding pad 225 positioned at the other edge.

Thereafter, the light emitting cell block 100 and the sub-mount substrate 200 are flip chip bonded.

Referring to FIG. 5D, the light emitting cell block 100 is flip-chip bonded to the sub-mount substrate 200, but is bonded by metal bumps 60 and 65 formed on the light emitting cell. The p-type metal bump 60 located at one edge of the light emitting cell block 100 is connected to the p-type bonding pad 220 of the sub-mount substrate 200, and the n-type metal bump 65 located at the other edge of the light emitting cell block 100 is connected to the sub type. It is connected to the n-type bonding pad 225 of the mount substrate 200. In this case, bonding may be performed by using heat or ultrasonic waves, or simultaneously using heat and ultrasonic waves.

In this embodiment, since the electrical connection is already completed through the bridge wiring 90 before the flip chip bonding, it is necessary to form a separate pattern for the electrical connection during flip chip bonding, or to consider the correct alignment accordingly. There is an advantage to reduce the burden.

After the flip-chip bonding of the light emitting cell block 100 to the sub-mount substrate 200, reflective particles 75 are interposed between the light-emitting cell block 100 and the sub-mount substrate 200 as shown in FIG. 5E. The underfill resin layer 70 was formed. As a result, the metal bumps 60 and 65 may be prevented from being oxidized, and the light emitting cell block 100 and the sub-mount substrate 200 may be kept in an electrically connected state, and the reflective particles 75 may be emitted from the light emitting layer. The light can be effectively reflected to the outside.

As a result, a plurality of light emitting cells are connected by conductive wiring to be flip chip bonded on the sub-mount substrate, and a flip-flop underfill resin layer filled with a resin containing reflective particles is formed in a space between the light-emitting cell block and the sub-mount substrate. A light emitting device having a chip structure can be manufactured. The light emitting cells may be variously connected in series, in parallel, or in parallel and according to a desired purpose, and may be used for lighting by being driven at a proper voltage and current, and may also be driven by AC power.

The technical spirit of the present invention is not limited to the above description, and various embodiments are possible, and may be manufactured in various structures and methods. For example, as described above, individual light emitting cells, which are not in the form of a plurality of light emitting cells connected at the wafer level, are flip chip bonded onto the sub-mount substrate to include reflective particles between the light-emitting cell and the sub-mount substrate through the same process. The light emitting element in which the underfill resin layer was formed can be manufactured.

The light emitting device and the method of manufacturing the same according to the present invention use an underfill technology to fill the space between the base substrate and the sub-mount substrate on which the light emitting layer is formed with a resin to protect from physical or chemical external environment as well as to deform thermal expansion according to temperature change. It also serves as a reinforcing material for the device, thereby improving the reliability of the device and extending its life.

In particular, the present invention forms an underfill resin layer including reflective particles that diffusely reflects light emitted from the light emitting layer, thereby preventing absorption of light and smoothly reflecting light, thereby obtaining high luminance and luminous efficiency. In addition, since the reflective particles uniformly distributed in the underfill resin layer widely diffuse the light emitted from the light emitting layer, there is an advantage in that light can be uniformly emitted in a wide range.

Claims (9)

A light emitting cell block on which a light emitting cell including an n-type semiconductor layer and a p-type semiconductor layer is formed on one surface of the base substrate; A sub-mount substrate on which the light emitting cell blocks are flip chip bonded; And An underfill resin layer filled in a space between the light emitting cell block and the sub-mount substrate, The underfill resin layer includes reflective particles that diffusely reflect light from the semiconductor layer. The method according to claim 1, And a plurality of light emitting cells spaced apart from each other on one surface of the base substrate, and an n-type semiconductor layer of the one light emitting cell and a p-type semiconductor layer of another light emitting cell adjacent thereto are connected to each other. The method according to claim 2, And a wire for connecting the n-type semiconductor layer of the one light emitting cell and the p-type semiconductor layer of the other one light emitting cell adjacent thereto. The method according to any one of claims 1 to 3, The reflective particle comprises Al, Ag or AlN. The method according to any one of claims 1 to 3, The reflective particles are spherical or rectangular in shape and have a size of 0.1 to 100 μm. The method according to any one of claims 1 to 3, The light emitting device according to claim 1, further comprising an insulating layer in a region excluding the flip chip bonded portion of the light emitting cell block. Forming a light emitting cell block by forming an n-type semiconductor layer and a p-type semiconductor layer on an upper surface of the base substrate; Flip chip bonding the light emitting cell blocks on a separate sub-mount substrate; And And filling the space between the light emitting cell block and the sub-mount substrate with a resin containing reflective particles to form an underfill resin layer. The method according to claim 7, Preparing the light emitting cell block, Removing a portion of the n-type and p-type semiconductor layers to form a plurality of light emitting cells; And And connecting the n-type semiconductor layer of one light emitting cell and the p-type semiconductor layer of another light emitting cell adjacent thereto through bridge wirings. The method according to claim 8, The bridge wiring is a method of manufacturing a light emitting device comprising connecting a n-type semiconductor layer of one light emitting cell and a p-type semiconductor layer of another adjacent light emitting cell through a bridge process or a step cover process. .

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