TWI406433B - Vertical gallium nitride based light emitting diode and manufacturing method thereof - Google Patents

Abstract

The present invention discloses a vertical LED of gallium nitride series and the manufacturing method thereof, wherein a planar layer is formed at one side of a light-emitting structure, and a reflection layer is formed on the planar layer. By the surface smoothness of the planar layer, the reflection efficiency of the reflection layer can be greatly increased, the light generated by the light-emitting structure can be fully guided out, the utilization efficiency of light can be raised, the brightness and usage lifetime of LED is increased, and thereby the user's demand can be satisfied.

Description

Vertical gallium nitride light-emitting diode and manufacturing method thereof

The present invention relates to a vertical gallium nitride-based light-emitting diode and a manufacturing method thereof, and more particularly to a structure and a manufacturing method for improving the brightness of a light-emitting diode.

The basic principle of a Light Emitting Diode (LED) is to generate light by combining electrons with a hole. In the case of a PN junction, electrons and holes are respectively injected into a depletion region when biased in the forward direction ( Depletion region), these injected electrons and holes are combined with each other, and their energy is released in the form of light.

Referring to FIG. 1 and FIG. 2, a conventional vertical gallium nitride-based light-emitting diode is formed by sequentially forming a light-emitting structure having a PN junction and an input voltage on a substrate 1. An electrical contact 3 and a reflective layer 4 having a high reflectivity and a conductive substrate 7, and then as shown in FIG. 2, the substrate 1 is removed, and a second electric current is formed on the other side of the light emitting structure 2. The contact 5 is roughened and the surface of the light-emitting structure 2 is roughened to form a light-emitting surface 6.

A vertical gallium nitride-based light-emitting diode is provided, and a voltage is supplied from the first electrical contact 3 and the second electrical contact 5, and the light-emitting structure 2 generates electrons and holes and combines with each other. And produce light. At this time, the reflective layer 4 can reflect the light source to guide the light toward the light-emitting surface 6. The surface of the light-emitting structure 2 is roughened to reduce the reflection to increase the amount of light, thereby forming a high-brightness light-emitting diode.

However, the structure of the light-emitting structure 2 and the reflective layer 4 is generally rugged, so that the reflection efficiency of the reflective layer 4 is greatly reduced, and the light of the light-emitting structure 2 cannot be effectively guided. It is injected to reduce the luminous efficiency of the light-emitting diode.

The main object of the present invention is to provide a vertical gallium nitride-based light-emitting diode which can effectively reflect light to guide light to be emitted from the light-emitting surface.

A secondary object of the present invention is to provide a method for fabricating a vertical gallium nitride-based light-emitting diode that can efficiently reflect light to improve light utilization efficiency.

In order to achieve the above object, the present invention is a vertical gallium nitride-based light-emitting diode comprising a light-emitting structure, a two-input electrode, a flat layer and a reflective layer. The manufacturing step includes: firstly preparing a substrate; then forming a light emitting structure on the substrate, the light emitting structure is a PN interface and can be driven by a voltage difference to generate a light; and then forming a light on the light emitting structure. An input electrode is disposed on the light emitting structure for inputting the voltage difference; then forming a flat layer on the light emitting structure and the input electrode, and allowing the flat layer to not completely cover the input electrode, and the flat The surface of the layer is formed as a flat surface; and then a reflective layer is formed on the flat surface of the flat layer; finally, the substrate on the light emitting structure is removed and another input electrode is formed on the light emitting structure.

As described above, the advantage of the present invention is that the flat surface can make the contact surface with the reflective layer no longer rough, so that the reflection efficiency of the reflective layer can be greatly improved, and the light of the light-emitting structure can be Efficient guidance and injection, increasing the luminous efficiency of the light-emitting diode.

The detailed description of the present invention and the technical description of the present invention are further illustrated by the accompanying drawings, but it should be understood that these embodiments are merely illustrative and not to be construed as limiting.

Referring to FIG. 3 and FIG. 4, the present invention is a vertical gallium nitride-based light-emitting diode comprising a light-emitting structure 10, two input electrodes 20, 60, a flat layer 30, and a reflection. The layer 40 and a conductive substrate 70, wherein the light emitting structure 10 is a PN interface and can be driven by a voltage difference to generate a light (not shown). The input electrodes 20, 60 are disposed on the light emitting structure 10 for input. This voltage differential.

The flat layer 30 is disposed on one side of the light emitting structure 10, and the flat layer 30 has There is at least one opening 31, the opening 31 is disposed on the input electrode 20 to expose the input electrode 20, and the surface of the flat layer 30 has a flat surface 32, and the flat layer 30 can be in a liquid state, and It is selected from any one of polymethylmethacrylate (PMMA) and polyimide (PI), epoxy resin (Epoxy Resin), and enamel resin (Silicons), and borrows a rotary machine (Fig. Uniformly swirled on one side of the light emitting structure 10, the flat layer 30 is a light sensitive material to harden the flat layer 30 and form the opening 31 by a yellow light developing process.

The reflective layer 40 is disposed on the flat surface 32 of the flat layer 30, and the reflective layer 40 may be selected from any one of silver (Ag) and aluminum (Al) to provide high reflectivity, and the light emitting structure 10 is further away from The surface of the light emitting structure 10 is roughened to form a light exiting surface 11.

The manufacturing process of the present invention is as follows:

First, in order to prepare the substrate 50, the substrate 50 is generally selected from the sapphire substrate 50, and the sapphire substrate 50 has good epitaxial characteristics, which can meet the requirements of the epitaxial formation of the light-emitting structure 10.

Next, a light emitting structure 10 is formed on the substrate 50. The light emitting structure 10 is a PN interface and can be driven by a voltage differential to generate light.

Next, an input electrode 20 is formed on the light emitting structure 10. The input electrode 20 is disposed on the light emitting structure 10 for input voltage difference.

A flat layer 30 is then formed on the light emitting structure 10 and the input electrode 20, and the flat layer 30 is not completely covered with the input electrode 20, and the surface of the flat layer 30 is formed as a flat surface 32.

Next, a reflective layer 40 is formed on the flat surface 32 of the flat layer 30, and the conductive substrate 70 is pasted or plated on the reflective layer.

Then, the substrate 50 on the light emitting structure 10 is removed and another input electrode 60 is formed on the light emitting structure 10, and the surface of the light emitting structure 10 can be roughened to form a light emitting surface 11.

As described above, by the arrangement of the flat surface 32, the contact surface with the reflective layer 40 can be no longer rough, so that the reflection efficiency of the reflective layer 40 can be greatly improved, and the light of the light-emitting structure 10 can be made. It is effectively guided and shot to increase luminous efficiency.

The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the embodiments of the present invention. That is, the equivalent changes and modifications made by the scope of the patent application of the present invention are covered by the scope of the invention.

Conventional knowledge

1. . . Substrate

2. . . Light structure

3. . . First electrical contact

4. . . Reflective layer

5. . . Second electrical contact

6. . . Glossy surface

7. . . Conductive substrate

this invention

10. . . Light structure

11. . . Glossy surface

20. . . Input electrode

30. . . Flat layer

31. . . Opening

32. . . Flat surface

40. . . Reflective layer

50. . . Substrate

60. . . Input electrode

70. . . Conductive substrate

FIG. 1 is a structural diagram of a semi-finished product of a conventional light-emitting diode.

2 is a structural view of a conventional light-emitting diode.

3 is a structural view of a semi-finished product of the light-emitting diode of the present invention.

4 is a structural view of a light-emitting diode of the present invention.

10. . . Light structure

11. . . Glossy surface

20. . . Input electrode

30. . . Flat layer

31. . . Opening

32. . . Flat surface

40. . . Reflective layer

60. . . Input electrode

70. . . Conductive substrate

Claims (10)

A vertical gallium nitride-based light-emitting diode includes: a light-emitting structure that is a PN interface and can be driven by a voltage difference to generate a light; and two input electrodes, the input electrode is disposed on the light-emitting structure And a flat layer, the flat layer is disposed on one side of the light emitting structure, and the input electrode is exposed, and the surface of the flat layer has a flat surface, and the flat layer is in a liquid state And selected from polymethylmethacrylate (PMMA), polyimide (PI), epoxy resin (Epoxy Resin) and enamel resin (Silicons), and borrowed a rotary machine Uniformly rotating on one side of the light emitting structure and hardening the flat layer by a yellow light developing process; a reflective layer disposed on a flat surface of the flat layer; and a conductive substrate disposed on the conductive substrate On the reflective layer. The vertical gallium nitride-based light-emitting diode according to claim 1, wherein the reflective layer is selected from the group consisting of silver (Ag) and aluminum (Al). The vertical gallium nitride-based light-emitting diode according to claim 1, wherein the flat layer has at least one opening that is disposed on the input electrode. The vertical gallium nitride-based light-emitting diode according to claim 1, wherein the light-emitting structure is roughened on a surface away from the light-emitting structure to form a light-emitting surface. A method for manufacturing a vertical gallium nitride-based light-emitting diode, the method comprising: preparing a substrate; forming a light-emitting structure on the substrate, the light-emitting structure being a PN interface and Driving a voltage differential to generate a light; forming an input electrode on the light emitting structure, the input electrode is disposed on the light emitting structure for inputting the voltage differential; forming a flat on the light emitting structure and the input electrode a layer, and the flat layer does not completely cover the input electrode, and the surface of the flat layer is formed as a flat surface, the flat layer is in a liquid state, and is selected from the group consisting of polymethylmethacrylate (PMMA), poly Asia Any of polyamine (PI), epoxy resin (Epoxy Resin) and enamel resin (Silicons), and uniformly spread on one side of the light-emitting structure by a rotary machine, and is developed by a yellow light developing process And hardening the flat layer; forming a reflective layer on the flat surface of the flat layer and forming a conductive substrate on the reflective layer; removing the substrate on the light emitting structure and forming another input electrode on the light emitting structure. The method for producing a vertical gallium nitride-based light-emitting diode according to claim 5, wherein the reflective layer is selected from the group consisting of silver (Ag) and aluminum (Al). The method of manufacturing a vertical gallium nitride-based light-emitting diode according to claim 5, wherein the flat layer has at least one opening that is disposed in the input electrode. The method for manufacturing a vertical gallium nitride-based light-emitting diode according to claim 7, wherein the flat layer is a light-sensitive material, and the opening is made by a yellow light developing process. The method for manufacturing a vertical gallium nitride-based light-emitting diode according to claim 5, wherein after the substrate on the light-emitting structure is removed and the other input electrode is formed on the light-emitting structure, The surface of the light emitting structure is roughened to form a light exiting surface. The method for manufacturing a vertical gallium nitride-based light-emitting diode according to claim 5, wherein the conductive substrate is formed on the reflective layer by any one of selective adhesion and plating.