KR20190116178A - Micro LED Package and Method for Manufacturing Thereof - Google Patents

Abstract

Disclosed are a micro-LED package capable of being quickly and easily controlled and a manufacturing method thereof. According to one aspect of the present invention, the manufacturing method of a micro-LED package comprises: a making process of making a thin film transistor (TFT) including a bonding electrode, a rear electrode disposed on the opposite side of the bonding electrode, and a bump disposed on the bonding electrode; a deposition process of depositing a micro-LED including the bonding electrode on a temporary substrate; a bonding process of bonding the bonding electrode of the micro-LED on the bump of the TFT; an underfill process of underfilling a space between the micro-LED and the TFT; a separation process of separating the micro-LED from the temporary substrate; a passivation process of passivating the micro-LED separated from the temporary substrate; a production process of performing dicing to include one micro-LED and one TFT to produce a micro-LED package; and a transfer process of transferring each micro-LED package produced in the production process to each corresponding substrate.

Description

Micro LED Package and Method for Manufacturing Thereof}

The present invention relates to a LED package of a micro size, such as micro LED, and a production method thereof.

The contents described in this section merely provide background information on the present embodiment and do not constitute a prior art.

One of the emerging display technologies is micro LEDs. As a display panel manufactured by using a small size RGB LED, it has received much attention because of its small size, high response speed, high brightness, and low power consumption.

In the method of producing such a micro LED, a conventional COB (Chip on Board) method has been used. The COB method is a method in which each fine RGB LED is directly disposed on a control board such as a TFT or a PCB and wire bonding is performed. Due to its relatively simple production method, it is widely used because of its excellent characteristics in terms of time and cost.

Conventionally, one controller (TFT etc.) controlled the RGB LED arrange | positioned on a control board. The problem is that the LED size becomes smaller, and the number of LEDs disposed on the control board increases. Since a large number of fine sized LEDs are disposed on the control board, there is a problem that the control device takes a long time to control each one individually.

Accordingly, there is an increasing demand for fine LEDs incorporating pixel-driven drivers for driving each of the fine LEDs disposed on the control board.

One embodiment of the present invention is to provide a fine LED package and a method of producing the same, including a drive driver in the fine size LED.

According to an aspect of the present invention, in the method of manufacturing a fine LED package, manufacturing a TFT comprising a bonding electrode, a rear electrode disposed on the opposite side of the bonding electrode and a bump disposed on the bonding electrode A deposition process for depositing a fine LED including a fabrication process and a bonding electrode on a temporary substrate, a bonding process for bonding the bonding electrode of the fine LED on a bump of the TFT, and an underfill between the fine LED and the TFT An underfill process, a separation process of separating the fine LED on the temporary substrate, a passivation process of depositing a coating thin film on the fine LED separated from the temporary substrate, and dicing the fine LED and the TFT to include one by one, respectively. A process of generating an LED package and moving each of the minute LED packages generated in the process to a counter substrate It provides a method for producing a fine LED package, characterized in that it comprises a moving process.

According to an aspect of the invention, the fine LED is characterized in that implemented as a flip chip (Flip Chip).

According to an aspect of the present invention, the bonding process is characterized in that the bonding electrode of the fine LED is bonded on the bump of the TFT using a laser reflow (Laser Reflow).

According to an aspect of the invention, comprising a bonding electrode, a rear electrode disposed opposite the bonding electrode and a TFT comprising a bump disposed on the bonding electrode and a bonding electrode bonded on the bump of the TFT, It provides a fine LED package comprising a fine LED to form one package with the TFT.

According to an aspect of the invention, the fine LED is characterized in that implemented as a flip chip (Flip Chip).

According to one aspect of the invention, the fine LED is characterized in that bonded on the bump of the TFT using a laser reflow (Laser Reflow).

As described above, according to an aspect of the present invention, by producing a fine LED package including a drive driver in the fine size LED, there is an advantage that can be quickly and easily control the fine LED.

1 is a view showing a fine LED package according to an embodiment of the present invention.
2 to 7 is a view showing a process for producing a fine LED according to an embodiment of the present invention.
8 to 12 illustrate a process for manufacturing a TFT according to an embodiment of the present invention.
13 to 16 illustrate a process of fabricating a fine LED package by combining a fine LED and a TFT manufactured according to an embodiment of the present invention.
17 is a flowchart illustrating a method of producing a fine LED package according to an embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. It is to be understood that the term "comprises" or "having" in the present application does not exclude in advance the possibility of the presence or addition of features, numbers, steps, operations, components, parts or combinations thereof described in the specification. .

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a view showing a fine LED package according to an embodiment of the present invention.

Referring to FIG. 1, the micro LED package 100 according to an embodiment of the present invention includes a micro LED 110 and a TFT 120.

The fine LED 110 emits light without a color filter. The fine LED 110 refers to an ultra-small LED that generates and outputs light of a color to be output by itself without a color filter for generating color. The fine LED 110 typically has a micro LED.

The TFT 120 is disposed at the bottom of the fine LED 110 and is connected to the counter substrate 130 to control each of the fine LEDs 110. In the fine LED package 100, the TFT 120 is disposed at the bottom of each fine LED 110 (for example, may be any one of a fine R LED, a fine G LED, or a fine B LED), so that each fine LED Control the operation of (110). As the TFTs 120 for controlling the fine LEDs 110 are disposed in the respective fine LED packages 100, the fine LED packages 100 can more easily control each fine LED 110, and more. Each fine LED 110 can be controlled quickly.

The fine LED package 100 is fabricated and transferred onto the counter substrate 130, in particular the solder 135.

The counter substrate 130 includes a solder 135 on the surface.

The solder 135 is an alloy used for soldering and the like, and serves as an electrode that is connected to the electrodes of the micro LED package 100 to supply power. For example, the solder 135 may be implemented with an alloy such as AgSn or SnAgCu. At the same time, the solder 135 may have a higher adhesive force than that of the film or the temporary sheet. When the micro LED package 510 approaches or contacts the solder 135, the micro LED package 510 may be separated from the grown film or the temporary sheet and transferred to the solder 135.

The solder 135 is disposed at each position where the micro LED package 510 is transferred on the counter substrate 130. Typically, since the plurality of fine LED packages 100 are transferred to the counter substrate 130 at regular intervals, the solder 135 corresponding thereto is also disposed on the counter substrate 130 at regular intervals. In addition, the solder 135 is disposed as many as to be connected to the electrodes of each TFT 120 included in the fine LED package 100.

The solder 135 may be implemented in the form of a solder ball.

2 to 7 is a view showing a process for producing a fine LED according to an embodiment of the present invention.

Referring to FIG. 2, a light emitting layer growth process of growing light emitting layers 210 and 220 for emitting light on the temporary substrate 230 is performed. Here, the light emitting layers 210 and 220 may be implemented with gallium nitride (GaN), but are not necessarily limited thereto, and may be implemented with various materials according to the color of the fine LED to emit light or the size of the manufactured fine LED. .

Referring to FIG. 3, a light emitting layer etching process of etching a portion 310 of the first light emitting layer 210 and the second light emitting layer 220 is performed. A portion 310 of the second light emitting layer 220 is etched at regular intervals so that each of the generated fine LEDs can be electrically insulated and easily separated and diced.

A portion 320 of the first light emitting layer 210 is etched so that the N electrode can be disposed. A portion 320 of the first light emitting layer 210 is etched so that the N electrode connected to the second light emitting layer 220 may be disposed.

Referring to FIG. 4, referring to FIG. 4, a deposition process of the reflective film 410 is performed to deposit the reflective film 410 on the top of the first emission layer 210. The reflective film 410 is deposited on the top of the first light emitting layer to serve as a P electrode, and at the same time reflects the light emitted from the first light emitting layer 210 to emit light in a predetermined direction (upper).

The reflective film 410 may be implemented with Ni / Ag, but is not limited thereto, and any material capable of producing the above-described effects may be replaced with any material.

Referring to FIG. 5, an electrode arrangement process of arranging the N electrode 510 as an etched portion of the first emission layer 210 is performed. Accordingly, power may be applied to each of the light emitting layers 210 and 220 via the electrodes 410 and 510.

The N electrode 510 may be implemented as Cr / Au, but is not limited thereto.

Referring to FIG. 6A, an insulating film deposition process for depositing an insulating film 610 is performed to separate the components to be deposited on the outside and the top. An insulating film 610 is deposited on top of the previously grown or deposited configuration to protect the previously grown or deposited composition (light emitting layer, electrode) from the outside and to separate it from other components to be deposited thereon.

Referring to FIG. 6B, a polishing process for planarizing a surface is performed so that a bonding electrode may be subsequently deposited on the deposited insulating film. The polishing process may be, for example, chemical mechanical polishing (CMP), but is not limited thereto. Since the height difference may occur between the reflective film 410 and the N electrode 510 serving as the P electrode, the height difference between the electrodes may be eliminated by grinding together with the insulating film.

Referring to FIG. 7, a bonding electrode deposition process for depositing a bonding electrode 710 for bonding on the deposited insulating layer 610 is performed. The bonding electrode 710 deposited on the insulating layer 610 is connected to the reflective layer 410 and the N electrode 510, respectively. Since the bonding electrodes 710 have a small area of each electrode 410 and 510, the bonding electrodes 710 expand the area of each electrode, and easily supply power to the light emitting layers 210 and 220 using the bonding electrodes 710 from the outside. It serves to supply.

The fine LED 100 is manufactured through each process shown in FIGS. 2 to 7. Each of the plurality of fine LEDs 100, which emit the same color on the temporary substrate 230, is fabricated.

8 to 12 illustrate a process for manufacturing a TFT according to an embodiment of the present invention.

Referring to FIG. 8, a TFT deposition process for depositing a thin film transistor (TFT) 810 on a wafer 820 is performed.

Referring to FIG. 9, an etching process of etching the deposited TFT 810 is performed. In order to separate the TFTs to be disposed in each fine LED 100, the TFTs 810 are etched at regular intervals 910.

Referring to FIG. 10, a deposition process of depositing a bonding electrode 1010 on a TFT 810 is performed. The bonding electrode 1010 is bonded with the bonding electrode 710 of the fine LED 100 to control the fine LED 100.

Referring to FIG. 11, a grinding process of grinding the wafer 820 of the TFT 810 may be performed to have a thickness suitable for inclusion in the micro LED package 100.

Thereafter, an electrode deposition process for depositing an electrode 1110 to be connected with the counter substrate 130, in particular, the solder 135, is performed on the opposite side where the TFT 810 of the wafer 820 is deposited.

Referring to FIG. 12, a bump ball deposition process for depositing a bump ball 1210 on each bonding electrode 1010 deposited on a TFT is performed. As the bonding electrode 1010 is bonded with the bonding electrode 710 of the fine LED 100, a bump ball 1210 is deposited on the bonding electrode 1010 to increase the bonding efficiency.

13 to 16 illustrate a process of manufacturing a fine LED package by combining a fine LED and a TFT manufactured according to an embodiment of the present invention.

Referring to FIG. 13, a bonding process of bonding the fine LEDs 110 onto the TFTs 120 using laser reflow is performed. In particular, the bonding electrode 710 in the fine LED 110 is bonded onto the bonding electrode 1010 or bump ball 1210 in the TFT 120. In this case, laser reflow may be used in the bonding process. As laser reflow is used, a bonding electrode 710 in the fine LED 110 may be bonded onto the bump ball 1210 in the TFT 120. The fine LED 110 is implemented in the form of a flip chip in which electrodes are directly connected to the TFT 120 without a separate intermediate medium.

Referring to FIG. 14, an underfill process of underfilling an insulating material 1410 is performed between the fine LED 110 and the TFT 120. After the underfill process, the temporary substrate 230 is separated at the interface between the fine LEDs 110, in particular, the light emitting layers 210 and 220, where shock waves are generated and a large pressure is applied to the interfaces. The interface is separated by this pressure. At this time, the fine LED 110, in particular, the light emitting layers 210 and 220 are subjected to a large shock by the shock wave. This impact also partially affects the light emitting layers 210 and 220, and has a great influence between the fine LED 110 and the TFT 120. Due to such an effect, a problem may occur in which the fine LED 110, in particular, the light emitting layers 210 and 220 are damaged. Accordingly, as the insulating material 1410 having the low viscosity property is injected and cured between the fine LED 110 and the TFT 120, the temporary substrate 230 is separated from the fine LED 110 to buffer shock waves generated. . In addition, as the underfill process is performed, chemical shifts that may occur due to external physical shock, heat, dust, etc. of the fine LED 110 and the TFT 120 are prevented.

Referring to FIG. 15A, after the underfill process is completed, a separation process of separating the fine LEDs 110 from the temporary substrate 230 is performed. Since all of the processes of manufacturing the fine LED 110 and bonding the TFT 120 are performed, the temporary substrate 230 is separated from the fine LED 110.

Referring to FIG. 15B, after the temporary substrate 230 is separated, a passivation process of passivating the fine LEDs 110 is performed. After the separation process is performed, one surface of the fine LED 110 deposited on the temporary substrate 230 is exposed to the outside. Accordingly, physical and chemical deformation or damage may occur in the fine LED 110, so that the passivation process is performed on one surface of the fine LED 110 from which the temporary substrate 230 is separated. In the passivation process, a coating thin film 1510 having a low refractive index and high hardness is deposited on the fine LEDs 110 to protect the fine LEDs 110. The deposited coating thin film 1510 may have a value of 1.4 to 1.6 as a refractive index.

Referring to FIG. 16A, after the passivation process is completed, a dicing process for separating the fine LED packages 100a, 100b, and 100c is performed. When passivation is complete, the completed fine LED packages are separated into each fine LED package. The plurality of fine LED packages passivated are diced so that the fine LEDs 110 and the TFTs 120 are each included in each fine LED package. As described above, the fine LEDs 110 and the TFTs 120 are etched at regular intervals, and then are deposited and generated. Accordingly, each fine LED package 100a, 100b, 100c is manufactured.

FIG. 16B illustrates a transfer process in which the respective fine LED packages 100a, 100b, and 100c are transferred to the counter substrate 130. Using laser transfer, each of the fine LED packages 100a, 100b, 100c is transferred to a predetermined position of the counter substrate 130. In particular, it is transferred onto the solder 135 on the counter substrate 130.

17 is a flowchart illustrating a method of producing a fine LED package according to an embodiment of the present invention.

A bonding process of bonding the fine LEDs 110 onto the TFTs 120 using a laser is performed (S1710). The fine LED 110 manufactured through the manufacturing process illustrated in FIGS. 2 to 7 is bonded onto the TFT 120. In this case, laser reflow may be used, such that the fine LED 110 may be bonded onto the TFT 120 without removing the bump ball 1210.

An underfill process of underfilling between the fine LEDs 110 and the TFTs 120 is performed (S1720). The insulating material underfills between the fine LED 110 and the TFT 120.

A separation process of separating the temporary substrate 230 in which the fine LEDs 110 are grown is performed (S1730). Since all of the processes of manufacturing the fine LED 110 and bonding the TFT 120 are performed, the temporary substrate 230 is separated from the fine LED 110.

After dicing so that each of the fine LEDs 110 and the TFTs 120 are included, each fine LED package is separated, and then a dicing process and a transfer process of transferring to the counter substrate 130 are performed (S1740).

In FIG. 17, each process is described as being sequentially executed, but this is merely illustrative of the technical idea of the exemplary embodiment of the present invention. In other words, a person of ordinary skill in the art to which an embodiment of the present invention belongs may change the order of the processes described in each drawing or execute one or more of the processes without departing from the essential characteristics of the embodiment of the present invention. 17 is not limited to the time series since the processes may be applied in various ways.

Meanwhile, the processes illustrated in FIG. 17 may be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. That is, the computer-readable recording medium may be a magnetic storage medium (for example, ROM, floppy disk, hard disk, etc.), an optical reading medium (for example, CD-ROM, DVD, etc.) and a carrier wave (for example, the Internet Storage medium). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which the present embodiment belongs may make various modifications and changes without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of the present embodiment but to describe the present invention, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

100: Fine LED Package
110: fine LED
120: TFT
130: counter substrate
135: solder
210, 220: light emitting layer
230: temporary substrate
410: reflecting film
510: N electrode
610: an insulating film
710, 1010: bonding electrode
810: TFT
820: wafer
1110: electrode
1210: bump ball
1410: insulation material
1510: coated thin film

Claims (1)

A TFT comprising a bonding electrode, a rear electrode disposed opposite the bonding electrode, and a bump disposed on the bonding electrode; And
Including a bonding electrode bonded on the bump of the TFT, and comprises a fine LED to form a package with the TFT,
The fine LED emits light without a color filter,
The TFT is a fine LED package, characterized in that for controlling the operation of the fine LED in each fine LED package.