WO2018072065A1

WO2018072065A1 - Led chip manufacturing method and led chip

Info

Publication number: WO2018072065A1
Application number: PCT/CN2016/102301
Authority: WO
Inventors: 张金勇; 罗剑生; 王磊
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2016-10-18
Filing date: 2016-10-18
Publication date: 2018-04-26

Abstract

Provided are an LED chip manufacturing method and an LED chip. The LED chip manufacturing method comprises: manufacturing a light-emitting unit respectively on an upper surface and a lower surface of an LED chip substrate (11) during an LED chip manufacturing process. Each of the upper surface and lower surface of the LED chip substrate (11) is provided with a light-emitting unit. Compared with a traditional LED chip, the LED chip manufactured by the LED chip manufacturing method can realize twice the number of quantum wells within a same chip area by means of a structure design in which a light-emitting unit is manufactured both on the upper surface and lower surface of the LED chip substrate (11), and without causing reliability issues. The LED chip has a good lighting effect, is brighter than a traditional LED chip of the same area, and features a longer service life, good reliability, a simple process, low cost, and a greater market value.

Description

LED chip manufacturing method and LED chip

Technical field

The invention relates to the technical field of LED chips, in particular to an LED chip manufacturing method and an LED chip.

Background technique

LED lamps are widely used in the world market, with small size, high brightness, low power consumption, low heat generation, long service life, environmental protection, etc., and have a variety of colors, deeply received by consumers. favorite. At the same time, LED chips as backlights play an indispensable role in electronic products that require display screens, such as mobile phones and televisions. As the size of electronic products continues to shrink, the size of LED chips is also required to be greatly reduced. Therefore, the world's major LED chip manufacturers have been committed to the development of high-efficiency chip structure.

Considering the structure of the LED chip itself, in order to generate more photons per unit area, the mainstream technology is to increase the number of quantum wells in the active area of the LED chip. The mechanism of LED chip illumination is the hole and current when the current passes through the quantum well of the active region of the chip. The radiant composite luminescence of electrons, the more quantum wells represent the greater the chance of generating radiant luminescence.

By increasing the number of quantum wells in the active region to obtain higher brightness, it will encounter the bottleneck of development. The quantum well is mainly to improve the composite efficiency. The more complex the quantum well, the higher the complex efficiency, but it cannot be infinitely limited. The wall thickness between the quantum well and the quantum well. If there are too many quantum wells, the wall will be thin and electron tunneling will occur, resulting in uneven distribution of the quantum well. In addition, the thickness of the active portion of an LED chip is about several micrometers. Designing a large number of quantum wells in such a thin interval will inevitably cause a concentration of heat flux, which will cause a series of reliability problems, and the service life will be greatly reduced. Related data shows that as the number of wells increases, electrons can be injected into more quantum wells, reducing the density of carriers in the active region, thereby reducing the Auger recombination effect. When the number of wells increases, due to the accumulation of polarization, band bending and carrier leakage are severe, resulting in a decrease in device performance. In addition, increasing the number of quantum wells not only wastes raw materials during epitaxial growth, but also increases The difficulty of quantum well growth makes it difficult to prepare high quality quantum wells.

Summary of the invention

Embodiments of the present invention provide a method for fabricating an LED chip, which is capable of achieving double the number of quantum wells under the same size of the chip area without causing reliability problems. The LED chip fabrication method is in the process of manufacturing the LED chip. A light emitting unit is formed on each of the upper and lower surfaces of the LED chip substrate.

Embodiments of the present invention also provide an LED chip for achieving double the number of quantum wells under the same size of chip area without causing reliability problems. The upper and lower surfaces of the LED chip substrate each have a light emitting unit.

In the LED chip manufacturing method of the embodiment of the invention, the structure design of the light-emitting unit is formed by the upper and lower surfaces of the LED chip substrate, and the LED chip produced can realize double quantum under the same-sized chip area compared with the conventional LED chip. The number of wells does not cause reliability problems. The LED chip of the embodiment of the invention has high luminous efficiency, is brighter than the conventional chip in the same area, has a longer life, good reliability, simple process, low cost, and has greater market value.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work. In the drawing:

1 is a schematic structural view of a conventional LED chip according to an embodiment of the present invention;

2 is a schematic structural view of an LED chip according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an LED chip package form according to an embodiment of the present invention.

detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The illustrative embodiments of the present invention and the description thereof are intended to explain the present invention, but are not intended to limit the invention.

In the embodiment of the present invention, a method for fabricating an LED chip is provided. The LED chip produced by the method has high luminous efficiency, is brighter than a conventional chip in the same area, has a longer life, is more reliable, and has a simple process and a cost. Low, with greater market value. The LED chip manufacturing method of the embodiment of the invention can make an LED chip with an active area on both sides of the substrate without changing the process flow of the existing LED chip, thereby making the number of quantum wells The design is multiplied.

The structure of the conventional LED chip is first described. FIG. 1 is a schematic structural view of a conventional LED chip involved in the embodiment of the present invention. As shown in FIG. 1 , in the conventional LED chip, the substrate 11 is provided with an N-type buffer layer 12 and N. The pattern layer 13, the active region quantum well 15, the p-type layer 16, the transparent conductive layer 17, the positive electrode 18, and the negative electrode 14. Traditional LED chips are roughly process flow, for example, fabricating substrates, structural design, buffer layer growth, N-type GaN layer growth, and more Quantum well luminescent layer growth, P-type GaN layer growth, annealing, detection (photofluorescence, X-ray), epitaxial wafer, design, processing reticle, photolithography, ion etching, N-type electrode (coating, annealing, etching) , P-type electrode (coating, annealing, etching), dicing, chip sorting, grading, etc. Since the conventional LED chip production process has been developed to be quite mature, the general process flow will be described here by way of example only, and those skilled in the art are familiar with the fact that there may be some details of the process during the specific production process.

In the LED chip manufacturing method of the embodiment of the invention, in the LED chip manufacturing process, one light emitting unit is formed on each of the upper and lower surfaces of the LED chip substrate. In the embodiment, one light-emitting unit is respectively formed on the upper and lower surfaces of the same substrate, and the upper and lower light-emitting units can be sequentially produced according to the above-mentioned conventional LED chip process, which is relatively simple to implement. Of course, those skilled in the art can also understand that, in the specific implementation, the process flow can be changed as needed on the basis of the above-mentioned conventional LED chip process to produce an LED chip that meets the requirements. That is, in the LED chip of the embodiment of the present invention, each of the upper and lower surfaces of the LED chip substrate has one light emitting unit.

In a specific example, forming one light emitting unit on each of the upper and lower surfaces of the LED chip substrate may include: forming a light-emitting unit of uniform size on each of the upper and lower surfaces of the LED chip substrate. In the implementation, one and the same light-emitting unit are respectively formed on the same substrate, and the size of the light-emitting unit on the upper and lower surfaces is kept uniform, and only one production process is repeated, and the production line configuration is not required to be adjusted, which is suitable for mass production. That is, in the example, in the LED chip of the embodiment of the invention, the size of the upper and lower surface light emitting units of the LED chip substrate are the same.

In a specific implementation, the light emitting unit is formed on the upper surface or the lower surface of the LED chip substrate, and may include forming an N-type buffer layer, an N-type layer, an active region quantum well, a P-type layer, a transparent conductive layer, and a positive layer on the substrate. Electrode and negative electrode. That is, in an example, in the LED chip of the embodiment of the present invention, the upper surface or lower surface light emitting unit of the LED chip substrate includes an N-type buffer layer, an N-type layer, an active region quantum well, and a P-type layer formed on the substrate. , a transparent conductive layer, a positive electrode and a negative electrode.

2 is a schematic structural view of an LED chip according to an embodiment of the present invention. As shown in FIG. 2, in the LED chip of the embodiment of the present invention, an N-type buffer layer 22, an N-type layer 23, and an active region quantum are disposed on the upper surface of the substrate 21. a well 25, a P-type layer 26, a transparent conductive layer 27, a positive electrode 28, and a negative electrode 24; an N-type buffer layer 29, an N-type layer 30, an active region quantum well 31, and a P-type layer are provided on the lower surface of the substrate 21. 32. A transparent conductive layer 33, a positive electrode 34 and a negative electrode 35.

In a specific example, the LED chip manufacturing method of the embodiment of the present invention may further include: connecting positive electrodes of two light emitting units on the upper and lower surfaces of the LED chip substrate to each other, and two light emitting units on the upper and lower surfaces of the LED chip substrate The negative electrodes are connected to each other to form a surface patch and are attached to the substrate in a flip chip soldering manner. In this way, the LED chip packaging process of the embodiment of the present invention can be simplified.

In a specific example, the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate may be connected to each other by gold wires or copper wires, and/or the upper and lower surfaces of the LED chip substrate may be two by gold wires or copper wires. The negative electrodes of the light-emitting units are connected to each other to achieve good electrical conductivity.

That is, the LED chip package form of the embodiment of the present invention may be: the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other, and the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other to form a surface. SMD form and attached to the substrate in flip-chip solder. In one example, the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other by gold wires or copper wires; and/or the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are gold wires or The copper wires are connected to each other.

3 is a schematic diagram of an LED chip package form according to an embodiment of the present invention. As shown in FIG. 3, the positive electrode 28 of the upper surface light emitting unit of the LED chip substrate and the positive electrode 34 of the lower surface light emitting unit of the LED chip substrate are connected to each other. The negative electrode 24 of the upper surface light emitting unit of the LED chip substrate and the negative electrode 35 of the lower surface light emitting unit of the LED chip substrate are connected to each other to form the positive electrode 36 and the negative electrode 37 in the form of surface patches, respectively, and are attached in a flip chip soldering manner. On the substrate 38. The circle in Fig. 3 represents a connection line structure such as a gold wire or a copper wire for connecting two positive electrodes or two negative electrodes.

In summary, in the LED chip manufacturing method of the embodiment of the present invention, the structure design of the light emitting unit is formed by the upper and lower surfaces of the LED chip substrate, and the LED chip fabricated under the same size chip area can be compared with the conventional LED chip. Achieve double the number of quantum wells without causing reliability problems. The LED chip of the embodiment of the invention has high luminous efficiency, is brighter than the conventional chip in the same area, has a longer life, good reliability, simple process, low cost, and has greater market value.

The LED chip of the embodiment of the invention can also be designed in the form of a surface patch, which makes the packaging process simple. The embodiment of the present invention can design an active area on one side of a very mature LED substrate which has been developed at present, and design an active area on the other side, and the process and conditions can be the same as the conventional LED chip, and the implementation is not realized. difficult.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computers are available Program instructions to a processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that instructions executed by a processor of a computer or other programmable data processing device are generated for implementation in a process A device or a plurality of processes and/or block diagrams of a device in a block or a plurality of blocks.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

The above described specific embodiments of the present invention are further described in detail, and are intended to be illustrative of the embodiments of the present invention. All modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

A method for fabricating an LED chip, characterized in that, in the process of fabricating an LED chip, one light-emitting unit is formed on each of the upper and lower surfaces of the LED chip substrate.
The method for fabricating an LED chip according to claim 1, wherein each of the light-emitting units is formed on each of the upper and lower surfaces of the LED chip substrate, and comprises: forming a uniform size illumination on the upper and lower surfaces of the LED chip substrate. unit.
The LED chip manufacturing method according to claim 1, wherein the light emitting unit is formed on the upper surface or the lower surface of the LED chip substrate, comprising forming an N-type buffer layer, an N-type layer, and an active region quantum on the substrate. A well, a P-type layer, a transparent conductive layer, a positive electrode, and a negative electrode.
The method of fabricating an LED chip according to claim 1, further comprising:

The positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other, and the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other to form a surface patch form, and are attached to the flip chip soldering form. On the substrate.
The LED chip manufacturing method according to claim 4, wherein the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other, including the upper and lower sides of the LED chip substrate by gold wires or copper wires. The positive electrodes of the two light emitting units on the surface are connected to each other;

And/or, the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other, and the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other by a gold wire or a copper wire.
An LED chip is characterized in that each of the upper and lower surfaces of the LED chip substrate has a light emitting unit.
The LED chip according to claim 6, wherein the upper and lower surface light emitting units of the LED chip substrate have the same size.
The LED chip according to claim 6, wherein the upper surface or lower surface light emitting unit of the LED chip substrate comprises an N-type buffer layer, an N-type layer, an active region quantum well formed on the substrate, P-type layer, transparent conductive layer, positive electrode and negative electrode.
The LED chip according to claim 6, wherein the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other, and the negative electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are mutually The connection is formed into a surface patch form and attached to the substrate in a flip chip soldering form.
The LED chip according to claim 9, wherein the positive electrodes of the two light emitting units on the upper and lower surfaces of the LED chip substrate are connected to each other by a gold wire or a copper wire; and/or the LED chip substrate The negative electrodes of the two light-emitting units on the upper and lower surfaces are connected to each other by a gold wire or a copper wire.