KR101093208B1 - Led with lens diffusing light and the manufacturing method thereof - Google Patents

Abstract

PURPOSE: An LED and a manufacturing method thereof are provided to improve the productivity of a product using the LED by installing the LED on a board to a chip on board type. CONSTITUTION: One side of a board layer(10) is processed as a convex lens shape. A first semiconductor layer(22), a light-emitting layer(24), a second semiconductor layer(26), and an LED layer(20) are successively laminated. A second semiconductor electrode layer(36) is laminated and formed in a side which is touched with the second semiconductor layer. A first semiconductor electrode layer(34) is insulated with the light-emitting layer and the second semiconductor layer. The first semiconductor electrode layer passes through the center part of the LED layer in order to be electrically connected with the first semiconductor layer.

Description

LED with diffused lens and its manufacturing method {LED WITH LENS DIFFUSING LIGHT AND THE MANUFACTURING METHOD THEREOF}

The present invention improves the light diffusion efficiency of the LED (LED), and relates to an LED having a diffusion lens mounted on the board by a chip on board packaging (Chip on Board Packaging) and a manufacturing method thereof.

In general, LEDs (hereinafter referred to as "LEDs") are widely used in various lighting fixtures or display devices that are widely used at present because of low power consumption and semi-permanent life.

Inorganic LEDs among the LEDs include a P-type semiconductor layer, a light emitting layer, and an N-type semiconductor layer that are stacked on top of a substrate by an epitaxial growth method such as chemical vapor deposition. In this case, a sapphire substrate that is heat-resistant and light-transmissive is generally used so that the substrate can be applied to a high temperature environment for epitaxial growth. The organic LED has a structure in which a polymer material in which electrode layers are formed on both sides of a substrate is laminated.

The inorganic LED and the organic LED of the above-described configuration emit light by injecting electrons and holes from the electrodes when power is applied to the respective electrodes and recombining them through the excited state.

The light generated from the LED having the above-described configuration and functions has a straightness, so that the LED itself is not suitable for illuminating a large area.

Therefore, the LED of the prior art needs to be able to diffuse the light to perform lighting for a large area.

 For this reason, in the prior art, as in the case of the "semiconductor light emitting element" disclosed in Korean Laid-Open Patent Publication No. 1998-086740 (Prior Art 1), the LED and the lead frame are connected by wiring to form a light emitting surface. The upper surface is formed in a dome shape with the upper region of the leaf frame to produce an LED unit ('semiconductor light emitting device' in the related art 1) as a unit light emitting body. In this way, the LED is protected not only by the dome-type resin, but also the light propagating from the inside of the resin is diffused by the resin can be performed to illuminate a large area.

However, in the above-described prior art, since a molding process of sealing an additional dome resin is performed after fabricating an LED device, it is difficult to manufacture an LED unit as a unit light emitter.

Therefore, in the present invention, the hemispherical lens is formed integrally in the thin film deposition process of the LED to protect the LED itself, as well as to diffuse the light generated from the device, and to perform the molding process without sealing the resin with a separate resin. An object of the present invention is to provide an LED having a diffusion lens that improves the diffusibility and the protection performance of the LED element.

In addition, the present invention is a diffusion lens that allows the LED itself to be mounted on the board in the form of a chip on a board (chip on board) without the wiring or separate packaging by the LED having a flip-chip structure It is another object to provide an LED having a.

In another aspect, the present invention is to provide an LED manufacturing method in which the diffusion lens is formed integrally.

An LED having a diffusion lens of the present invention for achieving the above object is a substrate layer processed on one surface convex lens shape, and the first semiconductor layer, the light emitting layer and the second surface on the opposite side of the surface forming the lens shape An LED layer formed by sequentially stacking semiconductor layers; a second semiconductor electrode layer formed on a surface in contact with the second semiconductor layer to supply power to the second semiconductor layer; and the light emitting layer and the second semiconductor layer; And a first semiconductor electrode layer which is insulated and is formed through the central portion of the LED layer to be electrically connected to the first semiconductor layer.

The second semiconductor electrode layer may be formed by stacking a conductive reflective metal layer.

The LED may further include an oxide transparent electrode layer between the second semiconductor layer and the second semiconductor electrode layer.

The second semiconductor layer may further include a convex convex lens unit having a plurality of convex convex lenses formed by etching on a surface on which the oxide transparent electrode layer is stacked and arranged in a lattice shape and convex toward the oxide transparent electrode layer.

The oxide transparent electrode layer may further include a reflective convex lens unit having a plurality of reflective convex lenses formed by etching on a surface bonded to the second semiconductor electrode layer and disposed in a lattice shape and convex toward the second semiconductor electrode layer. .

LED manufacturing method having a diffusion lens of the present invention for achieving the above object, the LED layer forming process of forming an LED layer by sequentially growing the first semiconductor layer, the light emitting layer and the second semiconductor layer on the substrate layer And forming a dielectric tube by etching the LED layer to form a groove in the center portion, and then forming an insulating layer, and removing the center portion of the grown insulating layer by etching. Forming a first semiconductor electrode by growing a conductive material for supplying power to the first semiconductor layer inside the assembling; and forming an upper portion of the second semiconductor layer in an outer region of the insulating tube. A conductive metal layer is grown on an upper surface of the first semiconductor electrode, a second semiconductor electrode layer is formed on the second semiconductor layer, and a first on the first semiconductor electrode. Substrate etching process and, by etching a surface exposed to the outside of the substrate for processing in a lens shape;; reverse reflective metal layer forming process of forming a conductor electrode layer including characterized in that formed.

The LED fabrication method may further include forming the second semiconductor layer during the LED layer forming process and forming the lattice in a lattice form by etching the surface of the second semiconductor layer on which the oxide transparent electrode layer is stacked. The method may further include forming a focused convex lens portion to form a focused convex lens portion having a plurality of convex convex lenses.

The LED manufacturing method may further include an oxide transparent electrode layer forming process of forming a conductive oxide transparent electrode layer on the second semiconductor layer in the outer region of the insulating tube after the first semiconductor electrode forming process. have.

In the oxide transparent electrode layer forming process, after forming the oxide transparent electrode layer, a reflective convex lens having a plurality of reflective convex lenses formed by etching on a surface contacting with the second semiconductor electrode layer and disposed in a lattice shape and convex toward the second semiconductor electrode layer direction is formed. The method may further include a process of forming a reflective convex lens forming a portion.

The present invention diffuses the light generated from the LED, as well as the LED to form a diffusion lens that can protect the LED itself integrally formed in the LED thin film deposition process without the molding process of sealing with a separate resin LED light The effect of improving the diffusibility and the protection performance of the LED element.

In addition, the present invention provides an effect of lowering the production cost and productivity of the LED by not having to perform wiring or separate packaging by the LED having a flip-chip (flip-chip) structure.

In addition, the present invention provides the effect of improving the productivity of the product using the LED by allowing the LED itself to be mounted on the board in the form of a chip on board (chip on board) without performing wiring or separate packaging.

1 is a cross-sectional view of the LED 100 according to the first embodiment of the present invention,
FIG. 2 is a cross-sectional view of the LED 100 viewed along the line II-II of FIG. 1 and viewed in the II direction.
3 is a flow chart showing a manufacturing method of the LED 100 of FIG.
4 is a cross-sectional view of the LED 200 according to the second embodiment of the present invention,
5 is a flowchart illustrating a method of manufacturing the LED 200 of FIG. 4.

Hereinafter, with reference to the accompanying drawings showing embodiments of the present invention will be described in more detail the present invention.

In the description of the LEDs 100 and 200 of the present invention, the LED layer 20 and the anti-reflective film electrode layer 30 are laminated from the substrate layer 10 by a thin film deposition process in an upward direction, and then the LED deposition process is completed. , 200 is flipped over and the substrate layer 10 is formed of a diffusion lens by etching. 1 and 3, the upper and upper surface directions of the substrate layer 10 are described as 'bottom' and 'down direction'.

FIG. 1 is a cross-sectional view of the LED 100 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the LED 100 cut along the line II-II of FIG. 1 and viewed in the II direction.

As shown in FIG. 1 and FIG. 2, the LED 100 is formed of a hemispherical lens by etching, and is deposited on the upper surface of the substrate layer 10, sputtering, chemical vapor deposition, and epitaxy. LED layer 20, insulating tube 12, n-side electrode 13 (first semiconductor electrode), retroreflective film electrode layer 30 which are laminated by selectively applying a thin film deposition process and a photolithography process, etc. It is configured to include).

The substrate layer 10 is configured to perform a function of a diffusion lens for diffusing light by forming an epi wafer formed by using a sapphire substrate as a base into a hemispherical lens shape by etching. As a result, the light generated in the LED layer 20 by the substrate layer 10 may be diffused by the substrate layer 10 without forming a separate diffusion member such as an epoxy resin formed by molding, thereby expanding the light irradiation range. .

The LED layer 20 is an n-type GaN type semiconductor 22 (hereinafter, referred to as a 'first semiconductor layer 22') formed by a thin film deposition process on the substrate layer 10, and a first semiconductor. The light emitting layer 24 laminated on the upper surface of the layer 22 and the p-type GaN based semiconductor layer 26 formed on the upper surface of the light emitting layer 24 (hereinafter referred to as 'second semiconductor layer 26') It is composed of.

In order to enhance the light diffusion effect in the above-described configuration, the refractive index of the substrate layer 10 is greater than 1 and has a value less than or equal to the refractive index of the first semiconductor layer 22.

Insulated tube 12 is formed in the center of the LED layer 20 to penetrate the LED layer 20 up and down, and is formed to be electrically connected to the first semiconductor layer 22 inside the insulating tube 12. A first semiconductor electrode 13 formed of a conductive material or an n-type GaN-based semiconductor material is formed. The insulating tube 12 and the first semiconductor electrode 13 are formed to have the same height as that of the retroreflective electrode layer 30.

The retroreflective electrode layer 30 is deposited on the conductive oxide transparent electrode layer 32 and the oxide transparent electrode layer 32 which are formed by a thin film deposition process on the LED layer 20 outside the insulation tube 12. The second semiconductor electrode layer 34 is formed, and the first semiconductor electrode layer 36 is formed on the upper surface of the first semiconductor electrode 13 by vapor deposition with the second semiconductor electrode layer 34.

The oxide transparent electrode layer 32 is formed by forming a conductive oxide transparent electrode layer 32 such as ITO or doped ZnO (ZnO) on the upper surface of the second semiconductor layer 26 in an outer region of the insulating tube 12. do. In addition, the second semiconductor electrode layer 34 and the first semiconductor electrode layer 36 may be formed of a metal having excellent reflective properties such as Al, Ag, Pt, Cr, etc. and having excellent electrical conductivity. It is formed by growing on the upper surface of the first semiconductor electrode 13 formed inside of.

In the above-described configuration, the second semiconductor electrode layer 34 deposited on the outside of the insulating tube 12 performs a function of an electrode for supplying power to the second semiconductor layer 26. The formed first semiconductor electrode layer 36 performs a function of an electrode for supplying power to the first semiconductor layer 22 through the first semiconductor electrode 13.

3 is a flowchart illustrating a method of manufacturing the LED 100 of FIG. 1.

Hereinafter, a method of manufacturing the LED 100 of FIG. 1 will be described in more detail with reference to FIGS. 1 to 3.

In order to manufacture the LED 100, the sapphire substrate 11 is grown and formed (S10: substrate layer forming process). A buffer layer (not shown) may be formed on the top surface of the sapphire substrate 11 to facilitate deposition growth of the LED layer 20.

After the substrate layer 10 is formed, a first semiconductor layer (n-type GaN-based semiconductor layer) 22 is laminated by applying a thin film deposition process such as deposition, sputtering, chemical vapor deposition, or epitaxy (S21: first). 1 semiconductor layer formation process).

After the first semiconductor layer 22 is formed, an insulating layer such as SiO ₂ is grown, and then the center of the LED layer 20 is formed to form the insulating tube 12 and the first semiconductor electrode 13 by lithography. The insulating layer 12 is removed from the insulating layer to form an insulating tube 12 formed with a groove communicating with the first semiconductor layer 22 (S22: insulating tube forming process).

Thereafter, the first semiconductor electrode 13 is formed by depositing the first semiconductor material or the conductive material in the insulating tube 12 (S24: first semiconductor electrode forming process).

After the first semiconductor electrode 13 is formed, the light emitting layer 24 (S24: light emitting layer forming process) and the second semiconductor layer 26 are sequentially formed by sequentially performing a thin film deposition process in an external region of the insulating tube 12. (S26: second semiconductor layer forming process) is deposited.

In the above process, the first semiconductor layer forming process S21, the light emitting layer forming process S24, and the second semiconductor layer forming process S26 become the LED layer forming process S20.

After the formation of the LED layer 20 is completed, an oxide is deposited by depositing a conductive oxide such as ITO or doped ZnO (ZnO) on the upper surface of the second semiconductor layer 26 located in the outer region of the insulating tube 12. The transparent electrode layer 32 is formed (S40: oxide transparent electrode forming process).

Subsequently, metals having excellent reflectivity and excellent electrical conductivity such as Al, Ag, Pt, Cr, etc. are deposited and grown on the upper surface of the oxide transparent electrode layer 34 and the upper surface of the first semiconductor electrode 13. As a result, as shown in FIG. 2, the outer region of the insulating tube 12 is a second semiconductor electrode layer 34 that supplies power to the second semiconductor layer 26 while reflecting light introduced through the oxide transparent electrode layer 34. do. The first semiconductor electrode 13 is formed as a first semiconductor electrode layer 36 that supplies power to the first semiconductor layer 22 through the first semiconductor electrode 13 in the insulating tube 12. (S60: retroreflective metal layer formation process). The oxide transparent electrode layer 32 and the second semiconductor electrode layer 34 become a retroreflective electrode layer 30.

After the second semiconductor electrode layer 34 and the first semiconductor electrode layer 36 are formed by the retroreflective metal layer forming process (S60), an upper portion of the substrate layer 10 positioned on the upper surface of the LED 100 is etched to form a substrate. The layer 10 is processed into a spherical lens shape (S70: substrate etching process).

In the substrate etching process S70, after the LED 100 is rotated, a photosensitive agent is applied to the bottom surface of the substrate layer 10, and a photosensitive, developing and heating method is performed using a mask having a disk-shaped pattern corresponding to the diameter of the LED 100. To form a cured photoresist layer having a diameter of the LED 100, and to reduce the thickness of the edge region of the photoresist to have a predetermined slope value by applying a reflow method to etch into a hemispherical lens shape The method of performing may be applied.

In the above-described process, the insulation tube forming process S22 and the first semiconductor electrode forming process S23 are performed after the formation of the LED layer 20 is finished or after the retroreflective metal layer forming process S60 is finished. May optionally be performed.

That is, the first semiconductor layer forming process (S22) for forming the first semiconductor layer 22, the light emitting layer forming process (S24) for forming the light emitting layer 24, and the second semiconductor layer (p-type GaN based semiconductor layer) 26 The second semiconductor layer forming process (S26) of forming the (1) is performed to form an LED layer 20 in which the first semiconductor layer 22, the light emitting layer 24 and the second semiconductor layer 26 are stacked (S20: LED layer formation process).

After the LED layer 20 is formed, the center of the LED layer 20 is etched to form a groove in which the insulating tube 12 is to be located, and then an insulating layer is formed inside the groove and the etching is performed again. This may be done by growing the first semiconductor electrode 13 after forming the associative 12. In this case, the first semiconductor electrode 13 is formed of a conductive material such as a conductive oxide forming the oxide transparent electrode layer 32.

By manufacturing the LED 100 according to the process of Figure 3, since the substrate layer 10 serves as a lens to diffuse the light emitted from the light emitting layer 24 to seal the resin for the diffusion of light during the manufacture of the LED It is not possible to perform operations such as molding.

In addition, since the oxide transparent electrode layer 32 and the second semiconductor electrode layer 34 have conductivity, the oxide transparent electrode layer 32 and the second semiconductor electrode layer 34 function as a second electrode for supplying power to the second semiconductor layer 26. The first semiconductor electrode 13 has a flip chip structure which performs a function of a first electrode which supplies power to the first semiconductor layer 22. Accordingly, by connecting the first semiconductor electrode layer 36 and the second semiconductor electrode layer 34 directly to the board, the LED 100 can be mounted on the board in the form of a chip on board. Therefore, by reducing the process such as wiring or packaging for mounting the board of the LED 100 improves the productivity of the product requiring the LED (100).

4 is a cross-sectional view of the LED 200 according to the second embodiment of the present invention, Figure 5 is a flow chart showing the processing of the LED 200 manufacturing method of FIG.

As shown in FIGS. 4 and 5, the LED 200 focuses on the upper surface of the second semiconductor layer 26 in addition to the configuration of the LED 100 of FIGS. 1 and 2 to further improve light extraction efficiency. The convex lens part 27 and the reflective convex lens part 33 formed on the upper surface of the oxide transparent electrode layer 32 are further comprised.

The convex convex lens part 27 has a spherical surface on an upper surface of the second semiconductor layer 26 by applying a reflow method, and is formed integrally with the second semiconductor layer 26 and has a lattice shape. Is formed by forming the condensed convex lens 27a by etching. Formation of the convex lens portion 27 is a convex lens portion forming process S30 performed after the second semiconductor layer forming process S26 in FIG. 5.

When the oxide transparent electrode layer 32 is formed on the second semiconductor layer 26 on which the convex lens portion 27 is formed, the bottom surface of the oxide transparent electrode layer 32 is focused by the convex lenses 27a. It is formed of a plurality of focusing concave lenses 33a concaved to correspond to the convex lenses 27a.

In addition, the reflective convex lens unit 33 is integrally formed with the oxide transparent electrode layer 32 in a spherical surface by photolithography which performs etching by applying a reflow method to an upper surface of the oxide transparent electrode layer 32. It is formed by forming a plurality of reflective convex lenses 33a which are formed and arranged in a lattice shape. Formation of the reflective convex lens unit 33 is a reflective convex lens forming process (S60) performed after the oxide transparent electrode layer forming process (S40) during the processing of FIG. 5.

The center of the convex lens 27a and the center of the reflective convex lens 33a formed by the convex lens forming process S30 and the reflective convex lens forming process S50 are positioned on the same vertical line.

The thickness of the oxide transparent electrode layer 32 is smaller than the radius of the reflective convex lens 33a and larger than the radius of the focused convex lens 27a, and the radius of the focused convex lens 27a is larger than the distance between the focused convex lenses 27a. Big.

The refractive index of the oxide transparent electrode layer 32 is formed to have a value smaller than the refractive index of the second semiconductor layer 26.

In addition, the oxide transparent electrode layer 32 having the above structure is formed of a thin film having a thickness of 200 nm or less in order to minimize the absorption of light.

In addition, the convex convex lenses 27a formed on the upper surface of the second semiconductor layer 22 and the reflective convex lenses 33a formed on the upper surface of the oxide transparent electrode layer 32 are convexly formed in the same direction. As a result, the path of light propagating inside the oxide transparent electrode layer 32 is minimized, thereby further minimizing light absorption by the oxide transparent electrode layer 32.

In addition, the refractive index of the oxide transparent electrode layer 32 is smaller than that of the second semiconductor layer 26. As a result, light incident on the oxide transparent electrode layer 32 through the second semiconductor layer 26 is refracted at an angle greater than the angle of incidence so that the incident light is incident on the reflective concave mirror 34a. The light reflected by the reflective concave mirror 34a is refracted to have an angle smaller than the angle of incidence when the light is reincident into the second semiconductor layer 26 through the convex convex lens 27a. Since the generated light is emitted to the outside in a direction substantially parallel to the incident direction, the light extraction efficiency is improved by about 40% or more compared to the LED on which the retroreflective electrode layer 30 is not formed.

Processes other than the focused convex lens forming process (S30) and the reflective convex lens forming process (S50) of FIG. 5 are the same processes as those of FIG.

In the present invention, the convex convex lens and the reflective convex lens may be composed of a concave concave lens and a concave concave lens which are concave with respect to a light emission direction as necessary.

100, 200: LED
10: substrate layer, 20: LED layer, 22: first semiconductor layer, 24: light emitting layer, 26: second semiconductor layer, 27a: focused convex lens, 27, 127: focused convex lens part
30: retroreflective film electrode layer, 32: oxide transparent electrode layer, 33a: reflective convex lens, 33: reflective convex lens portion, 34: first semiconductor electrode layer, 34a: reflective concave mirror, 36: first semiconductor electrode layer

Claims (9)

A substrate layer having one surface processed into a convex lens shape; and
An LED layer formed by sequentially stacking a first semiconductor layer, a light emitting layer, and a second semiconductor layer on an opposite surface of the lens-shaped surface;
A second semiconductor electrode layer laminated on a surface in contact with the second semiconductor layer to supply power to the second semiconductor layer; and
And a first semiconductor electrode layer insulated from the light emitting layer and the second semiconductor layer and formed to penetrate the central portion of the LED layer to be electrically connected to the first semiconductor layer. LED.
The method according to claim 1,
And the second semiconductor electrode layer is formed by laminating a conductive reflective metal layer.
The method according to claim 1,
And an oxide transparent electrode layer between the second semiconductor layer and the second semiconductor electrode layer.
The method according to claim 3,
The second semiconductor layer is formed by etching on the surface on which the oxide transparent electrode layer is stacked, disposed in a lattice shape, and further comprising a convex convex lens unit having a plurality of convex convex lenses convex toward the oxide transparent electrode layer. LED with a diffusion lens.
The method of claim 3, wherein the oxide transparent electrode layer,
The diffusing lens further comprises a reflective convex lens portion formed by etching on the surface bonded to the second semiconductor electrode layer and disposed in a lattice shape and having a plurality of reflective convex lenses convex toward the second semiconductor electrode layer. LED equipped.
An LED layer forming process of forming an LED layer by sequentially growing a first semiconductor layer, a light emitting layer, and a second semiconductor layer on the substrate layer; and,
Forming a dielectric tube after etching the central portion of the LED layer to form an insulating tube for insulating the first semiconductor electrode for supplying power to the first semiconductor layer;
A first semiconductor electrode forming step of forming a conductive first semiconductor electrode for supplying power to the first semiconductor layer inside the insulation tube;
In the outer region of the insulator tube, a conductive metal layer is grown on the second semiconductor layer and on the first semiconductor electrode to form a second semiconductor electrode layer on the second semiconductor layer, and the first semiconductor electrode. A retroreflective metal layer forming process of forming a first semiconductor electrode layer on an upper portion of the;
And a substrate etching process of etching the surface exposed to the outside of the substrate layer to form a lens shape.
The method of claim 6, after the formation of the second semiconductor layer during the LED layer formation process,
A convex convex lens portion is formed on the surface of the second semiconductor layer in which the retroreflective metal layer is stacked by etching to form a convex lens portion having a plurality of convex convex lenses convex in the direction of the retroreflective metal layer. LED manufacturing method having a diffusion lens, characterized in that further comprises;
The method of claim 6, wherein after forming the first semiconductor electrode,
And an oxide transparent electrode layer forming step of forming a conductive oxide transparent electrode layer between the second semiconductor layer and the second semiconductor electrode layer in an outer region of the insulator tube.
The method of claim 8, wherein the oxide transparent electrode layer forming process,
After the oxide transparent electrode layer is formed, a reflective convex lens portion is formed on the surface contacting the second semiconductor electrode layer by etching to form a reflective convex lens portion having a plurality of reflective convex lenses convex toward the second semiconductor electrode layer. LED manufacturing method having a diffusion lens characterized in that it further comprises a process.

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