KR101423929B1

KR101423929B1 - Light Emitting Diode device

Info

Publication number: KR101423929B1
Application number: KR1020070138000A
Authority: KR
Inventors: 히로시 무라타; 김유동; 신옥희
Original assignee: 삼성전자주식회사
Priority date: 2007-12-26
Filing date: 2007-12-26
Publication date: 2014-08-04
Also published as: KR20090070110A

Abstract

The present invention relates to a light emitting diode device, and more particularly, to a light emitting diode device including at least one small LED chip, a bump formed on one surface of the small LED chip and flip-bonding the circuit substrate with the bump, And a phosphor layer formed on the light emitting surface of the small LED chip.

Light emitting diodes, large area, high power

Description

[0001] Light emitting diode device [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (LED) device, and more particularly, to a light emitting diode device that converts a wavelength of a luminescent color using a phosphor powder to obtain a desired luminescent color.

2. Description of the Related Art In general, a light emitting diode (LED) is an electronic component that emits a small number of injected carriers (electrons or holes) by using a semiconductor p-n junction structure and emits light by recombination thereof. That is, when a forward voltage is applied to a semiconductor of a specific element, electrons and holes move through the junction between the anode and the cathode and recombine with each other. Since electrons and holes are separated from each other, energy becomes smaller. Release.

In particular, a wavelength-converted light emitting diode for realizing a white color is used as a substitute for a backlight of a lighting device or a display device. And is actively developed as a high-power, high-efficiency light source.

Recently, such a wavelength-converted light emitting diode is manufactured as a large-sized light emitting diode having a large area so as to be able to operate at a high current for use as a high-output, high-efficiency light source.

Hereinafter, a large-sized LED device according to the related art will be described in detail with reference to FIG.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout diagram showing electrodes and active regions of a large-sized light emitting diode device according to the prior art.

Referring to FIG. 1, an upper surface of a light emitting diode having a size of 1 mm 2 made of an n-type nitride semiconductor layer 120, an active layer, and a p-type nitride semiconductor layer (not shown) is sequentially formed on a substrate.

A p-type electrode 160 and an n-type electrode 150, which are respectively connected to the p-type nitride semiconductor layer and the n-type nitride semiconductor layer 120, are formed on the upper surface of the light emitting diode.

The n-type electrode 150 includes a plurality of n-type electrode pads 155 and a plurality of branched electrodes 150 'and 150 "extending therefrom. The n-type electrode 150 has a structure in which the p- Type electrode 160. The p-type electrode 160 is divided so that the light emitting area is divided through the branched electrodes 150 'and 150' 'of the n-type electrode 150. In this case, Here, reference numeral 165 denotes a p-type electrode pad.

That is, a plurality of n-type electrode pads 155 are provided on the n-type electrode 150 to disperse the current applied when the current is charged, and a plurality of branched electrodes 155 And the p-type electrode 160 are arranged in the form of fingers to improve the current diffusion efficiency, thereby preventing defective devices due to application of a large current.

However, in the conventional large-sized light emitting diode device as described above, if a current leakage due to crystal defects or the like occurs even in a single place, the characteristic becomes poor. When a large current is applied to the device, There is a problem that the driving voltage and characteristics of the device are reduced.

Further, when the size of a large-sized light emitting diode device is changed, a separate process operation is required depending on the size of the device such as a photomask change, which complicates the process.

Also, since the large-sized light emitting diode device repeatedly reflects and absorbs light inside the large-sized light emitting diode device until the emitted light is emitted to the side, there is a problem that the total amount of light emission is lost when light is emitted to the side.

An object of the present invention is to provide a light emitting diode device capable of realizing light emitting diode devices of various sizes using one or more small light emitting diode chips and improving light emitting efficiency and heat radiation characteristics have.

According to an aspect of the present invention, there is provided a light emitting diode chip comprising: at least one small LED chip; bumps formed on one surface of the small LED chip and flip-bonding the circuit substrate with the bumps; And a phosphor layer formed on the light emitting surface of the small LED chip.

In the light emitting diode device of the present invention, it is preferable that the white resin is made of a silicone resin containing a TiO ₂ pigment.

In addition, in the light emitting diode device of the present invention, it is preferable that the phosphor layer is made of a transparent epoxy or a silicone resin containing a phosphor powder.

In addition, in the light emitting diode device of the present invention, it is preferable that the small size LED chip is 0.2 mm in length, 0.5 mm in length, and 0.08 mm in height.

Also, in the light emitting diode device of the present invention, the small LED chip may include a substrate, an n-type nitride semiconductor layer formed on the substrate, the n-type nitride semiconductor layer being divided into a first region and a second region, An active layer formed on the first region; a p-type nitride semiconductor layer formed on the active layer; a p-type electrode formed on the p-type nitride semiconductor layer; and an n-type electrode formed on the second region of the n- .

According to another aspect of the present invention, there is provided a light emitting device comprising: at least one small LED chip; bumps formed on one surface of the small LED chip and flip-bonding the circuit substrate with the bumps; And a light emitting diode.

In order to realize a light emitting diode device of various sizes by using a plurality of small LED chips, the present invention provides a light emitting diode device having a larger size than a light emitting diode device according to the related art, The characteristics can be improved.

In addition, the present invention realizes light emitting diode devices of various sizes by using a plurality of small LED chips, so that a separate process such as changing the size of a photomask is not necessary in order to realize light emitting diode devices of various sizes, If a current leak due to a defect or the like occurs, only the small LED chip generated can be replaced, and thus the yield of manufacturing the device can be improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the drawings, the thickness is enlarged to clearly represent the layers and regions.

Example

2 and 3, a structure of a light emitting diode device according to an embodiment of the present invention will be described in detail. FIG. 2 is a plan view schematically showing the structure of a light emitting diode device according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along the line III-III 'of FIG.

2 and 3, a light emitting diode device according to an embodiment of the present invention includes at least one small LED chip 100, a circuit board (not shown), the small LED chip 100, And a bump 300 flip-bonded to the substrate.

The small LED chip 100 has a buffer layer (not shown) and an n-type nitride semiconductor layer 120 sequentially laminated on a substrate 110 which is transparent to light. At this time, the n-type nitride semiconductor layer 120 is divided into a first region and a second region, and the first region defines a light emitting surface, It is preferable that the area is formed larger than the area so as to improve the luminance characteristics of the device.

More specifically, the substrate 110 is a substrate suitable for growing a nitride semiconductor single crystal, and is preferably formed using a transparent material including sapphire. In addition to sapphire, the substrate 110 may be formed of zinc oxide (ZnO), gallium nitride (GaN), silicon carbide (SiC), and aluminum nitride (AlN).

The buffer layer is a layer for improving lattice matching with the substrate 110 before the n-type nitride semiconductor layer 120 is grown on the substrate 110, and may be omitted depending on process conditions and device characteristics.

The n-type nitride semiconductor layer 120 may be formed of a semiconductor material having an In _X Al _Y Ga ₁ _-X- _Y N composition formula (where 0? X, 0? Y, X + Y? 1). More specifically, the n-type nitride semiconductor layer 120 may be a GaN layer doped with an n-type conductive impurity or a GaN / AlGaN layer. Examples of the n-type conductive impurities include Si, Ge, Sn Or the like is used, and Si is mainly used.

An active layer 130 and a p-type nitride semiconductor layer 140 are sequentially stacked on the first region of the n-type nitride semiconductor 120 to form a light emitting structure.

The active layer 130 may be an InGaN / GaN layer having a multi-quantum well structure.

The p-type nitride semiconductor layer 140 may be made of a semiconductor material having an In _X Al _Y Ga ₁ _-X- _Y N composition formula (where 0? X, 0? Y, X + Y? 1). More specifically, the p-type nitride semiconductor layer 140 may be formed of a GaN layer or a GaN / AlGaN layer doped with a p-type conductivity type impurity. Examples of the p-type conductivity type impurity include Mg, Zn, Be Or the like is used, and Mg is preferably mainly used.

A p-type electrode 150 is formed on the p-type nitride semiconductor layer 140. The p-type electrode 150 preferably includes at least one layer selected from a reflective electrode, an ohmic contact electrode, and a transparent electrode. For example, the p-type electrode 150 may include a single layer or reflective electrode / ohmic contact electrode composed of a reflective electrode, an ohmic contact electrode, or a transparent electrode, an ohmic contact electrode / transparent electrode, / Transparent electrode / reflective electrode or the like and can be formed by selecting it according to process conditions and device characteristics.

An n-type electrode 160 is formed on the second region of the n-type nitride semiconductor layer 120. The second region of the n-type nitride semiconductor layer 120 is a region where a part of the light emitting surface is removed by mesa etching.

The light emitting diode device according to the present invention is formed on the surface of a circuit board (not shown) on which the small LED chip 100 is flip-bonded, and the side surfaces of the bump 300 and the small LED chip 100 And a phosphor layer 500 formed on the light emitting surface of the small LED chip 100. The phosphor layer 500 is formed on the light emitting surface of the LED chip 100,

The white resin 400 maintains the unique color of the small LED chip 100 and reflects light emitted to the side of the small LED chip 110 to the light emitting surface to secure the linearity of light And serves as a reflective layer. In this embodiment, a silicone resin containing TiO ₂ pigment as the white resin (400) was used.

4, the white resin 400 may be omitted depending on the characteristics of the device and the process conditions, and the phosphor layer may be disposed in a space where the white resin 400 is omitted. Here, FIG. 4 is a cross-sectional view showing a modification of the light emitting diode device according to an embodiment of the present invention.

The phosphor layer 500 may be formed of a transparent epoxy resin or a silicone resin containing a phosphor powder. At this time, the phosphor layer 500 may change the chromaticity depending on the thickness of the layer and the content of the phosphor powder.

In this embodiment, the thickness of the phosphor layer 500 is preferably as thin as 0.1 mm or less in order to improve the luminance, and the content of the phosphor powder is 1.0 or more times that of the transparent epoxy or silicone resin.

That is, the light emitting diode device according to the present invention has a structure capable of causing wavelength conversion by causing light generated from the small LED chip 100 to be emitted to the outside through the phosphor layer 500. For example, when the small LED chip 100 is a chip showing blue color, a white color is realized by using a yellow phosphor powder as a phosphor powder of the phosphor layer 500.

In the meantime, in this embodiment, a large-sized LED chip 100 having a size of 0.2 mm in width, 0.5 mm in length and 0.08 mm in height is arranged in a size of 2 × 5, But the present invention is not limited to this, and various sizes can be formed by changing the number of small LED chips.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout view showing electrodes and active regions of a large-sized light emitting diode device according to the related art; FIG.

2 is a bottom view schematically illustrating the structure of a light emitting diode according to an exemplary embodiment of the present invention.

3 is a cross-sectional view taken along line III-III 'of FIG.

4 is a sectional view showing a modification of the light emitting diode device according to an embodiment of the present invention.

Description of the Related Art

100: Small LED chip 300: Bump

400: White resin 500: Phosphor layer

Claims

A plurality of small LED chips arranged in rows and columns;

Bumps formed on one surface of the plurality of small LED chips and flip-bonded to the circuit board;

A white resin formed to surround side surfaces of the bumps and the plurality of small LED chips; And

And a phosphor layer formed to be connected to the light emitting surfaces of the plurality of small LED chips.

The method according to claim 1,

Wherein the white resin is made of a silicone resin containing TiO ₂ pigment.

The method according to claim 1,

Wherein the phosphor layer is made of a transparent epoxy or silicone resin containing phosphor powder.

The method according to claim 1,

Wherein each of the plurality of small LED chips is 0.2 mm in length, 0.5 mm in length, and 0.08 mm in height.

The method according to claim 1,

Each of the plurality of small LED chips includes a substrate, an n-type nitride semiconductor layer formed on the substrate and divided into a first region and a second region, an active layer formed on the first region of the n-type nitride semiconductor layer, A p-type nitride semiconductor layer formed on the active layer, a p-type electrode formed on the p-type nitride semiconductor layer, and an n-type electrode formed on the second region of the n-type nitride semiconductor layer Light emitting diode device.

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