KR101617525B1 - Flexible led and method for manufacturing the same - Google Patents

Abstract

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flexible LED having flexibility so that an LED element is bent well and a method of manufacturing the same. To this end, the present invention provides a semiconductor light emitting device including a first conductive semiconductor layer, an active layer, a second conductive semiconductor layer, and a reflective portion, wherein the first conductive semiconductor layer has a first electrode, And a flexible board which is flexible enough to bend in the heat dissipation unit is provided. Therefore, the present invention has an advantage that the LED element has flexibility to bend well.

Description

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

The present invention relates to a flexible LED and a manufacturing method thereof, and more particularly, to a flexible LED having flexibility such that an LED element is bent well, and a manufacturing method thereof.

2. Description of the Related Art In general, a light emitting diode (LED) is an electronic component that generates a small number of injected carriers (electrons or holes) by using a p-n junction structure of a semiconductor and emits light by recombination thereof.

In addition, LEDs are attracting attention as next-generation lighting due to their advantages such as environmental friendliness, long life and high efficiency.

As shown in FIG. 1, the LED includes a LED package 30 having an LED element 30 mounted on a printed circuit board 20. The LED element 30 includes a first conductive semiconductor layer, a second conductive semiconductor layer, An active layer is provided between the semiconductor layers, and light is generated and released to the outside by recombination of electrons and holes in the active layer.

Recently, vertical LEDs have been disclosed for reducing the energy loss in the LED by shortening the recombination distance of electrons and holes.

2 shows a structure of a general vertical type LED element, which includes a p-type electrode layer 32, a p-type semiconductor layer 33, an active layer 34 as an active region, and a p-type electrode layer 32 sequentially formed on a conductive substrate or a ceramic substrate 31, an n-type semiconductor layer 35, and an n-type electrode layer 36.

In this case, when a ceramic substrate is used, a via hole may be formed in the ceramic substrate for electrical conduction with the p-type electrode layer.

Meanwhile, the application range of such LED devices is being expanded from indoor lighting to outdoor street lamps, automobile and marine, undersea lighting, infrared lighting, ultraviolet lighting, and the like. In recent years, An LED package using a flexible substrate such as Korean Patent Laid-Open No. 10-2002-0030891 (a laminated package using a flexible substrate) has been proposed.

However, such an LED package has a problem in that the LED element is installed on a flexible substrate, but the LED element itself is not flexible enough to bend, so that the installation is limited to a curved surface.

Korean Patent Publication No. 10-2002-0030891

In order to solve such problems, it is an object of the present invention to provide a flexible LED having flexibility so that an LED element can bend well, and a manufacturing method thereof.

According to an aspect of the present invention, there is provided a flexible LED comprising: a first conductive semiconductor layer; an active layer; a second conductive semiconductor layer; a reflective portion laminated on the first conductive semiconductor layer; A second electrode is provided on the reflection portion, a heat dissipation portion for dissipating heat is provided on the reflection portion, and a flexible substrate having flexibility to bend well on the heat dissipation portion is provided.

Further, the flexible LED according to the present invention is characterized in that an insulating portion is further formed on a part of the second conductive semiconductor layer.

The first conductive semiconductor layer may be an n-type semiconductor material and the second conductive semiconductor layer may be a p-type semiconductor material. Alternatively, the first conductive semiconductor layer may be a p-type semiconductor material and the second conductive semiconductor layer may be an n- And is made of a semiconductor material.

The reflective portion may include at least one of ITO, IZO, Ag, Ni, Cu, Al, Ti, Pd, Pt, Ru, Au, Rh, Ir, W and WTi.

The heat dissipating unit according to the present invention may be made of one or more of the metals of Ti, Al, Ni, Au, Ag, Cu, Zn, Zr, Mo, Rh, Pd, Ir, Pt, W, .

In addition, the flexible substrate according to the present invention is a substrate made of a transparent transparent material, and is made of a resin such as a polyimide (PI) resin, a polyester resin, an acrylic resin, a polycarbonate (PC) resin, a polymethyl methacrylate ) Resin. ≪ / RTI >

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: a) sequentially forming a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate; b) forming a reflective portion on the second conductive semiconductor layer; c) depositing a heat dissipation part on the reflective part; d) bonding the flexible substrate to the heat dissipation unit; e) removing the substrate and forming a first electrode on the first conductive semiconductor layer; And f) etching the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer, and forming a second electrode in the reflective portion.

In addition, the step a) according to the present invention may further include the step of forming an insulating part on a part of the second conductive semiconductor layer.

In addition, the flexible substrate 180 of the step d) according to the present invention is characterized in that the flexible substrate 180 is bonded by any one of bonding using an adhesive material or eutectic bonding.

The present invention is advantageous in that the LED element is flexible enough to bend well.

1 is a perspective view of a typical LED package.
2 is a sectional view showing the structure of a general vertical type LED device.
3 is a cross-sectional view of a flexible LED according to the present invention.
4 is a cross-sectional view showing a structure of a flexible LED according to the present invention.
5 is a sectional view showing a structure of a flexible LED according to the present invention.
6 is a flowchart illustrating a manufacturing process of a flexible LED according to the present invention.
7 is a graph comparing a current / voltage of a flexible LED according to the present invention and a conventional vertical LED device.
8 is an exemplary view showing a flexible LED according to the present invention.
9 is an exemplary view showing an operation state of a flexible LED according to the present invention.

Hereinafter, a preferred embodiment of a flexible LED according to the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

(Flexible LED)

FIG. 3 is a cross-sectional view showing a flexible LED according to the present invention, FIG. 4 is a cross-sectional view showing a structure of a flexible LED according to the present invention, and FIG. 5 is a sectional view showing the structure of a flexible LED according to the present invention.

3 to 5, the flexible LED 100 according to the present invention includes a first conductive semiconductor layer 120, an active layer 130, a second conductive semiconductor layer 140, a reflective portion 160 A first electrode 121 is formed on the first conductive semiconductor layer 120 and a second electrode 141 is formed on a part of the reflective portion 160. The reflective portion 160 is formed on the first electrode 121, And a flexible substrate 180 having flexibility that allows the heat dissipation unit 170 to bend well is provided.

A bonding layer 181 for bonding the two materials may be interposed between the heat dissipation unit 170 and the flexible substrate 180.

The substrate 110 may be selected according to the material of the nitride semiconductor layer to be formed thereon, and preferably has a lattice constant similar to that of the nitride semiconductor layer, and may be a sapphire (Al 2 O 3), a silicon (Si), a spinel, , Silicon carbide (SiC), zinc oxide (ZnO), gallium arsenide (GaAs), gallium phosphorus (GaP), lithium-alumina (LiAl2O3), boron nitride (BN), aluminum nitride (AlN) And it is preferably a sapphire substrate.

In addition, the substrate 110 is separated by a laser separation method using a laser lift off method or a chemical separation method using a chemical substance.

The first conductive semiconductor layer 120 is formed on the substrate 110 with n-type AlxGayInzN (0? X, y, z? 1), and is preferably an n-type semiconductor layer.

The active layer 130 is formed on one side of the first conductive semiconductor layer 120 and is formed of AlxGayInzN (0 ≤ x, y, z ≤ 1), and has a single or multi-layer structure including at least one barrier layer and a well layer It can have a quantum well structure.

The second conductive semiconductor layer 140 is formed of p-type AlxGayInzN (0? X, y, z? 1) on one side of the active layer 120, and is preferably a p-type semiconductor layer.

The order of forming the first conductive semiconductor layer 120, the second conductive semiconductor layer 140 and the active layer 130 is different from that of the second conductive semiconductor layer 140 and the first conductive semiconductor layer 120 The second conductive semiconductor layer 140, the active layer 130, and the first conductive semiconductor layer 120 may be formed on one side of the substrate 110 in this order.

After the first and second conductive semiconductor layers 120 and 140 and the active layer 130 are formed on the substrate 110, a portion of the second conductive semiconductor layer 140 may have an arbitrary pattern The first electrode 150 and the second electrode 150 may be formed.

The insulating layer 150 is preferably made of SiO ₂ and the first and second conductive semiconductor layers 120 and 140 and the active layer 130 are etched, So that defects such as shorts can be prevented and damage to the reflective portion 160 can be prevented.

The reflective portion 160 is formed on the second conductive semiconductor layer 140 to reflect light. The reflective portion 160 may be formed of ITO, IZO, Ag, Ni, Cu, Al, Ti, Pd, Pt, Ru, Au, Rh, Ir, W, and WTi.

The heat dissipation unit 170 may be formed by depositing metal on the reflection unit 160 to allow heat generated during the operation of the flexible LED 100 to be emitted. And at least one of the metals of Ni, Au, Ag, Cu, Zn, Zr, Mo, Rh, Pd, W, WTi, Ir and Pt.

The flexible substrate 180 is made of a transparent material having flexibility and is made of a material such as polyimide resin, polyester resin, acrylic resin, polycarbonate (PC) resin, polymethylmethacrylate (PMMA) The material of the flexible substrate 180 is not limited thereto, and any flexible material that can be bent can be used as the flexible substrate 180.

In addition, the flexible substrate 180 is physically bonded to the heat dissipating unit 170 through a bonding layer 181 using an adhesive, or is fixed by eutectic bonding at a temperature of 200 ° C or lower.

The first electrode 121 is formed on the first conductive semiconductor layer 120 in which the substrate 110 is separated and the second electrode 141 is formed on the first and second conductive semiconductor layers 120 and 140, A part of the active layer 130 is etched to be provided on the open reflective part 160 to be electrically separated from the first electrode 121.

The first and second electrodes 121 and 141 may be formed of a metal such as Ti, Al, Ni, Cr, Au, Ag, Cu, Zn, Zr, Mo, Rh, Pd, W, ≪ / RTI >

(Flexible LED manufacturing method)

FIG. 6 is a flowchart illustrating a manufacturing process of a flexible LED according to the present invention, which will be described with reference to FIGS. 3 to 6. FIG.

For example, a sapphire substrate 110 is provided (S100), and a first conductive semiconductor layer 120, an active layer 130, and a second conductive semiconductor layer 140 are sequentially formed on the sapphire substrate 110 (S110).

The order of forming the first conductive semiconductor layer 120 and the second conductive semiconductor layer 140 may be reversed in step S110.

The first conductive semiconductor layer 120, the active layer 130, and the second conductive semiconductor layer 140 formed in step S110 may be formed of ITO, IZO, Ag, Ni, Cu, Al, Ti The reflective portion 160 is formed of at least one of Pd, Pt, Ru, Au, Rh, Ir, W, and WTi (S120).

The first conductive semiconductor layer 120, the active layer 130, and the second conductive semiconductor layer 140 are etched on the second conductive semiconductor layer 140 before the reflective portion 160 is formed. An insulating layer having an arbitrary pattern is formed on the side surface of the second conductive semiconductor layer 140 in order to prevent a defect caused by a short or the like from adhering to the side surface of the second conductive semiconductor layer 140 during the etching process, (150) may be formed.

The upper portion of the reflective portion 160 formed in the step S120 may be formed of Ti, Al, Ni, Au, Ag, Cu, Zn, Zr, Mo, Rh, A heat dissipation portion 170 formed of one of the metals of Pd, W, WTi, Ir, and Pt, or an alloy of at least one of the metals is formed through metal deposition (S130).

The upper surface of the heat dissipating unit 170 formed in step S130 may be made of any material that can be flexibly bonded to the upper surface of the heat dissipating unit 170. Preferably, the heat dissipating unit 170 may be formed of a polyimide resin, a polyester resin, The flexible substrate 180 is provided as a transparent substrate made of at least one resin selected from the group consisting of poly (methyl methacrylate) (PC) resin and polymethyl methacrylate (PMMA) resin (S140).

The flexible substrate 180 installed in step S140 is physically bonded to the heat dissipating unit 170 through the bonding layer 181 using an adhesive or the like, or may be physically bonded to the heat dissipating unit 170 170 are formed on the substrate.

When the installation of the flexible substrate 180 is completed in step S140, the substrate 110 is separated through a laser separation method or a chemical separation method using chemical substances (S150).

The first conductive semiconductor layer 120 may be formed of a metal such as Ti, Al, Ni, Cr, Au, Ag, Cu, Zn, Zr, Mo, Rh, Pd, W, A first electrode 121 made of a metal such as Ir or Pt and at least one of the metals is formed (S160).

A portion of the side surfaces of the first conductive semiconductor layer 120, the active layer 130 and the second conductive semiconductor layer 140 is etched (S170) until the insulating portion 150 or the reflective portion 160 is exposed, A metal such as Ti, Al, Ni, Cr, Au, Ag, Cu, Zn, Zr, Mo, Rh, Pd, W, Ir, or Pt is formed on the reflective portion 160 when the reflective portion 160 is exposed. And a second electrode 141 made of at least one of the metals (S180).

At this time, the process of forming the first electrode 121 and the process of forming the second electrode 141 may be performed in reverse order.

Comparing the flexible LED 100 fabricated through the above-described process with the operation characteristics of a conventional vertical LED, the current characteristics show almost similar characteristics as shown in FIG. 7, and FIGS. 8 and 9 show a flexible LED An actual product in which the semiconductor device 100 is manufactured, and an operation state of the actual product.

Accordingly, it is possible to provide a flexible LED having characteristics similar to conventional LEDs while having flexibility so that the LED element is bent well.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It can be understood that

In the course of the description of the embodiments of the present invention, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation, , Which may vary depending on the intentions or customs of the user, the operator, and the interpretation of such terms should be based on the contents throughout this specification.

100: Flexible LED
110: substrate
120: a first conductive semiconductor layer
121: first electrode
130: active layer
140: a second conductive semiconductor layer
141: second electrode
150:
160:
170:
180: flexible substrate

Claims (10)

delete delete delete delete delete delete delete a) sequentially forming a first conductive semiconductor layer 120, an active layer 130, and a second conductive semiconductor layer 140 on a substrate 110;
b) forming a reflective portion (160) on the second conductive semiconductor layer (140);
c) depositing a heat dissipating part (170) on the reflective part (160);
d) bonding the flexible substrate 180 to the heat dissipation unit 170;
e) removing the substrate 110 and forming a first electrode 121 on the first conductive semiconductor layer 120; And
f) etching the first conductive semiconductor layer 120, the active layer 130 and the second conductive semiconductor layer 140 and forming a second electrode 141 on a part of the reflective portion 160 The method comprising the steps of:
9. The method of claim 8,
wherein the step a) further comprises forming an insulating part (150) on a part of the second conductive semiconductor layer (140).
10. The method according to claim 8 or 9,
Wherein the flexible substrate 180 of the step d) is bonded to the heat dissipation unit 170 by any one of bonding using an adhesive material or eutectic bonding.

Images