WO2024014568A1 - Display device using light-emitting element, and manufacturing method therefor - Google Patents

Abstract

The present invention is applicable to a technical field related to display devices and, for example, relates to a display device using a micro light-emitting diode (LED), and a manufacturing method therefor. In this present invention, a display device using a light-emitting element comprises: a wiring board; and a plurality of pixels arranged on the wiring board, wherein each of the pixels may comprise: a first sub-pixel comprising a red fluorescent layer formed on a blue light-emitting element; a second sub-pixel comprising a green fluorescent layer formed on a blue light-emitting element; and a third sub-pixel comprising a blue light-emitting element.

Description

Display device using light-emitting elements and method of manufacturing the same

The present invention is applicable to display device-related technical fields and, for example, relates to a display device using micro LED (Light Emitting Diode) and a method of manufacturing the same.

Recently, in the field of display technology, display devices with excellent characteristics such as thinness and flexibility have been developed. In contrast, currently commercialized major displays are represented by LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diodes).

Meanwhile, Light Emitting Diode (LED) is a semiconductor light emitting device well known for converting current into light. Starting with the commercialization of red LED using GaAsP compound semiconductor in 1962, it has been followed by GaP:N series green LED. It has been used as a light source for display images in electronic devices, including information and communication devices. Accordingly, a method of solving the above-mentioned problems can be proposed by implementing a display using a semiconductor light-emitting device. The semiconductor light emitting device has various advantages over filament-based light emitting devices, such as long lifespan, low power consumption, excellent initial driving characteristics, and high vibration resistance.

The size of these semiconductor light emitting devices has recently been reduced to tens of micrometers. Therefore, when implementing a display device using such small-sized semiconductor light-emitting devices (LEDs), a very large number of semiconductor light-emitting devices must be assembled on the wiring board of the display device.

However, in the process of assembling these light emitting devices, there is a problem that it is very difficult to precisely position numerous semiconductor light emitting devices at desired positions on the wiring board. These problems are becoming more severe with higher resolution displays.

LED emits light with a short wavelength at half maximum (less than 50 nm) through a quantum well structure. White light is created through color conversion balance through phosphors in blue LED, which has the lowest manufacturing cost in the lighting market.

In the market related to displays using mini LEDs, due to issues related to image quality, colors are expressed by applying LEDs that emit blue, green, and red light to pixels. To implement unit pixels in the mini LED display market, including signage and cinema, the Pick and Place (PnP) method is used to transfer LED chips to a wiring board through a robot arm. The size of the mini LED must be larger than the suction chuck that can be processed and is usually larger than 100 ㎛.

For high-resolution applications where the pixel area is small, micro LED can be applied. Accordingly, the number of LED chips used increases, and the number of LED transfers can increase along with this. Therefore, processes and configurations that reduce the number of transfers in pixel production are needed.

As pixels shrink in size to the size of micro LEDs, COW (chip on wafer) manufacturing costs increase. As a high-resolution display application, phosphors can be used to emit green and red light through color conversion from blue LED.

To this end, a red phosphor can be used in a blue LED to implement a red subpixel. At this time, when the blue LED emits light, the emitted light excites the red phosphor layer to emit red light.

At this time, a portion of the light emitted from the blue LED may excite the green phosphor layer of the neighboring green subpixel to emit green light. Additionally, a blue component exists among the light that passes through the red phosphor layer, and the green phosphor layer can be excited by this blue component as well. This phenomenon in which unintended subpixels emit light can be referred to as a crosstalk phenomenon.

Conventionally, in order to prevent this crosstalk phenomenon, partition walls were sometimes formed between subpixels. However, not only does the number of steps increase due to the formation of such a partition, but there are also limitations in realizing resolution. Additionally, when forming a partition, problems may occur due to alignment tolerances. Meanwhile, the partition itself may be an obstacle to implementing flexibility.

As such, various problems exist when applying LED-based color conversion phosphors. Therefore, a method to solve these problems is required.

The technical problem to be solved by the present invention is to provide a display device using a light-emitting element that can implement a high-resolution display through phosphor color conversion and a manufacturing method thereof.

In addition, it is intended to provide a display device using a light-emitting device that can implement subpixels by efficiently forming a phosphor layer on the light-emitting device, and a method of manufacturing the same.

In addition, it is intended to provide a display device using a light-emitting device and a manufacturing method thereof that can reduce the transfer process of the light-emitting device and thereby reduce manufacturing costs.

In addition, it is intended to provide a display device using a light-emitting device and a manufacturing method thereof that can reduce the damage rate of the light-emitting device due to the phosphor structure during the manufacturing process.

As a first aspect for achieving the above object, the present invention provides a display device using a light emitting element, comprising: a wiring board; A first subpixel comprising a plurality of pixels arranged on the wiring board, each pixel including a red phosphor layer formed on a blue light emitting element; a second subpixel including a green phosphor layer formed on a blue light emitting device; and a third subpixel including a blue light-emitting element.

As an exemplary embodiment, the red phosphor layer and the green phosphor layer may be formed to a certain thickness on the blue light emitting device.

As an exemplary embodiment, the wiring board may further include a light shielding layer positioned between each pixel.

As an exemplary embodiment, the third subpixel may include a height compensation layer located on the blue light emitting device.

As an exemplary embodiment, the height compensation layer may compensate for a height difference between the third subpixel, the first subpixel, and the second subpixel.

As an exemplary embodiment, the first subpixel may further include a color filter located on the red phosphor layer.

As an exemplary embodiment, the color filter may include a blue light blocking filter.

As an exemplary embodiment, the second subpixel may further include a color filter located on the green phosphor layer.

As a second aspect to achieve the above object, the present invention provides a method of manufacturing a display device using a light-emitting device, comprising the step of transferring a plurality of blue light-emitting devices grown and divided on a growth substrate onto a first donor substrate. ; forming a red phosphor layer on a first blue light emitting device forming a first subpixel among the blue light emitting devices located on the donor substrate; forming a green phosphor layer on a second blue light emitting device forming a second subpixel among the blue light emitting devices located on the donor substrate; forming a color filter on the red phosphor layer and the green phosphor layer; transferring the first blue light-emitting device, the second blue light-emitting device, and the three blue light-emitting devices forming a third subpixel onto a second donor substrate; and transferring the first blue light-emitting device, the second blue light-emitting device, and the third blue light-emitting device onto a wiring board.

As an exemplary embodiment, the step of forming the red phosphor layer may form a red phosphor layer having a certain thickness locally on the first blue light-emitting device.

As an exemplary embodiment, the step of forming the green phosphor layer may form a green phosphor layer having a certain thickness locally on the second blue light-emitting device.

As an exemplary embodiment, after forming the color filter, the step of forming a height compensation layer on the three blue light emitting devices may be further included.

As an exemplary embodiment, the height compensation layer may compensate for a height difference between the first subpixel, the second subpixel, and the third subpixel.

As an exemplary embodiment, the height compensation layer may function as an impact cushioning layer during the transfer process.

As an exemplary embodiment, forming the red phosphor layer may include performing bar coating on a mask pattern masking the second blue light emitting device and the third blue light emitting device.

As an exemplary embodiment, forming the green phosphor layer may include performing bar coating on a mask pattern that masks the first blue light-emitting device and the third blue light-emitting device.

According to one embodiment of the present invention, the following effects are achieved.

First, according to an embodiment of the present invention, a high-resolution display can be implemented through phosphor color conversion of a blue light-emitting device by efficiently forming a red phosphor layer and a green phosphor layer.

Accordingly, only gallium nitride-based blue light-emitting devices can be used, thereby simplifying the manufacturing process.

Additionally, during the manufacturing process, the phosphor layer can act as an impact cushioning layer, thereby reducing the breakage rate of the light emitting device.

In addition, the height compensation layer to match the height of the phosphor layer during the manufacturing process can also act as an impact cushioning layer, further reducing the damage rate of the light emitting device.

Furthermore, according to another embodiment of the present invention, there are additional technical effects not mentioned here. Those skilled in the art can understand the entire purpose of the specification and drawings.

1 is a cross-sectional view showing unit pixels of a display device using a semiconductor light-emitting device according to an embodiment of the present invention.

Figure 2 is a cross-sectional view showing unit pixels of a display device using a semiconductor light-emitting device according to a comparative example.

3 to 14 are cross-sectional schematic diagrams showing manufacturing steps of a display device using a semiconductor light-emitting device according to an embodiment of the present invention.

15 to 17 are cross-sectional views showing examples of light-emitting elements of a display device using a semiconductor light-emitting element according to an embodiment of the present invention.

18 to 21 are cross-sectional schematic diagrams showing a manufacturing process that can be used in the process of forming a phosphor layer of a display device using a light-emitting device according to an embodiment of the present invention.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, it should be noted that the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical idea disclosed in this specification by the attached drawings.

Furthermore, although each drawing is described for convenience of explanation, it is within the scope of the present invention for a person skilled in the art to implement another embodiment by combining at least two or more drawings.

Additionally, when an element such as a layer, region or substrate is referred to as being “on” another component, it is to be understood that it may be present directly on the other element or that there may be intermediate elements in between. There will be.

The semiconductor light emitting devices mentioned in this specification include LEDs, micro LEDs, etc., and may be used interchangeably.

1 is a cross-sectional view showing unit pixels of a display device using a semiconductor light-emitting device according to an embodiment of the present invention.

Referring to FIG. 1 , a display device 10 is shown in which unit light emitting elements 310, 320, and 330 are each installed as subpixels on a substrate 110 of a wiring board 100.

The wiring board 100 may have a plurality of wiring electrodes (not shown) divided and positioned on the board 110 . Here, the wiring electrode may include a data electrode and a scan electrode.

Here, three light emitting elements 310, 320, and 330 may form a unit pixel. That is, the first light-emitting device 310 can form a first subpixel, the second light-emitting device 320 can form a second subpixel, and the third light-emitting device 330 can form a third subpixel. You can. Accordingly, each light emitting device 310, 320, and 330 and the subpixel will be described using the same reference numeral.

These unit pixels may be repeatedly provided on the wiring board 100. At this time, one light emitting device may form a unit subpixel. In FIG. 1, an insulating layer 130 or a cover layer 130 that covers the upper surface of the substrate 110 along with the unit pixels may be positioned on these unit pixels.

Although not shown, the wiring electrode arranged on the wiring board 100 may be connected to a TFT layer equipped with a thin film transistor (TFT). Data electrodes (pixel electrodes) may be connected to this TFT layer. A detailed description of this will be omitted.

The first light emitting device 310 forming the first subpixel 310 may have a horizontal structure. For example, the first light emitting device 310 may have a first type electrode and a second type electrode located on the same surface of the semiconductor layer. However, the embodiment of the present invention can be equally applied even when the first light emitting device 310 has a vertical structure.

Here, the first light-emitting device 310 may be a red light-emitting device that emits red light. Hereinafter, the first light-emitting device 310 will be described as an example of a red light-emitting device.

This first light-emitting device 310, that is, the first subpixel 310, may include a red phosphor layer 314 formed on a blue light-emitting device (light-emitting diode; LED) 311 capable of emitting blue light. You can. For example, the first light-emitting device 310 may include a red phosphor layer 314 formed on the blue light-emitting device 311.

Referring to FIG. 1, in the first subpixel 310, the red phosphor layer 314 may be formed on the blue light emitting device 311 to have a certain width and a certain thickness. For example, in the first subpixel 310, the red phosphor layer 314 may be formed on the blue light emitting device 311 to have a substantially uniform thickness and width. The red phosphor layer 314 may also be formed on the side of the blue light emitting device 311. That is, the red phosphor layer 314 may be formed to substantially cover all parts except the electrode of the blue light emitting device 311. For convenience of explanation, this blue light-emitting device 311 may be referred to as a first blue light-emitting device.

The red phosphor layer 314 may be formed by opening at least a portion of the N-type electrode and the P-type electrode of the blue light emitting device 311.

At this time, the thickness of the red phosphor layer 314 may be approximately 100 nm to 5 ㎛.

Meanwhile, the second light-emitting device 320 may be a green light-emitting device that emits green light. Hereinafter, the second light-emitting device 310 will be described as an example of a green light-emitting device.

This second light-emitting device 320, that is, the second subpixel 320, may include a green phosphor layer 324 formed on a blue light-emitting device (light-emitting diode; LED) 321 capable of emitting blue light. You can. For example, the first light-emitting device 320 may include a green phosphor layer 324 formed on the blue light-emitting device 321.

Referring to FIG. 1, in the second subpixel 320, the green phosphor layer 324 may be formed on the blue light emitting device 321 to have a certain width and a certain thickness. For example, in the second subpixel 320, the green phosphor layer 324 may be formed on the blue light emitting device 321 to have a substantially uniform thickness and width. The green phosphor layer 324 may also be formed on the side of the blue light emitting device 321. That is, the green phosphor layer 324 may be formed to substantially cover all parts except the electrode of the blue light emitting device 321. For convenience of explanation, this blue light-emitting device 321 may be referred to as a second blue light-emitting device.

The green phosphor layer 324 may be formed by opening at least a portion of the N-type electrode and the P-type electrode of the blue light emitting device 321.

At this time, the thickness of the green phosphor layer 324 may be about 100 nm to 5 ㎛.

The red phosphor layer 314 may include a red inorganic phosphor or a red quantum dot (QD) that converts blue light corresponding to a wavelength of 400 to 480 nm into a main wavelength band of 600 to 750 nm.

As an exemplary embodiment, the green phosphor layer 324 includes a green inorganic phosphor or green QD (Quantum Dot) that converts blue light corresponding to a wavelength of 400 to 480 nm into a dominant wavelength band of 490 to 600 nm. can do.

A color filter 316 may be provided on the red phosphor layer 314. This color filter 316 may also be formed by opening at least a portion of the N-type electrode and the P-type electrode of the blue light emitting device 311.

This color filter 316 may include a blue light blocking filter. In the red light-emitting device 310, in which the red phosphor layer 314 is formed on the blue light-emitting device 311, red light converted from blue light by the red phosphor layer 314 may be emitted, but along with this, blue light can be emitted. Light can also be emitted. Accordingly, the color filter 316 can block this blue light and allow the red light emitting device 310 to emit pure red light.

Additionally, a color filter 326 may be provided on the green phosphor layer 324. This color filter 326 may also be formed by opening at least a portion of the N-type electrode and the P-type electrode of the blue light emitting device 321.

This color filter 326 may include a blue light blocking filter. In the green light-emitting device 320, in which the green phosphor layer 324 is formed on the blue light-emitting device 321, red light converted from blue light by the green phosphor layer 324 may be emitted, but also blue light can be emitted. Light can also be emitted. Accordingly, the color filter 326 can block this blue light and allow the green light emitting device 320 to emit pure red light.

Although not shown in FIG. 1, the blue light emitting device 331 forming the third subpixel 330 may include a height compensation layer 334 (see FIG. 10).

This height compensation layer 334 can solve problems that may occur due to height differences during the transfer process of each subpixel (310, 320, and 330). For example, the first light-emitting element 310 forming the first subpixel 310 and the second light-emitting element 320 forming the second subpixel 320 may have a different height from the third light-emitting element 330. there is. Therefore, if adhesive pressure is required during the transfer process, appropriate pressure may not be applied to the third light emitting device 330. The height compensation layer 334 can prevent this phenomenon.

Meanwhile, this height compensation layer 334 may include a light diffusion agent. These light diffusers may include metal oxides, such as TiO ₂ .

Meanwhile, a red phosphor layer 314 is formed to a certain thickness on the blue light-emitting device 311 in the first light-emitting device 310, and a green phosphor layer is formed to a certain thickness on the blue light-emitting device 321 in the first light-emitting device 320. The phosphor layer 324 can also exert this impact-relieving effect.

Depending on the shape of the light emitting devices 311, 321, and 331, a light shielding layer 140 may be further provided on the substrate 110. Typically, the substrate 110 may be made of glass, and thus light emitted from the light emitting devices 311, 321, and 331 may propagate along the substrate 110. At this time, the light shielding layer 140 can prevent light emitted from the light emitting devices 311, 321, and 331 propagating along the substrate 110 from generating crosstalk.

However, according to one type of light emitting device 311, 321, or 331, this light shielding layer 140 may not be necessary. For example, when a vertical light emitting device is used, light propagating to the substrate 110 may be blocked by the electrode of the light emitting device, so the light shielding layer 140 may not be necessary.

Crosstalk may not occur between the subpixels 310, 320, and 330 of the display device 10 even if there is no member such as a partition wall that blocks light. For example, as display resolution increases, the spacing between light-emitting devices also decreases, so a crosstalk phenomenon may occur in which one light-emitting device causes a neighboring light-emitting device or a phosphor layer formed on the light-emitting device to emit light. This phenomenon is explained with reference to FIG. 2.

Figure 2 is a cross-sectional view showing unit pixels of a display device using a semiconductor light-emitting device according to a comparative example.

Referring to FIG. 2, it shows a display device in which unit light emitting elements 31, 32, and 33 are each installed as subpixels on a wiring board 11.

Here, the red phosphor layer 21 is located on the blue light-emitting device (light-emitting diode; LED) 31 capable of emitting blue light, forming a red subpixel.

Meanwhile, a green phosphor layer 22 is located on a blue light-emitting device (light-emitting diode; LED) 32 capable of emitting blue light, thereby forming a green subpixel.

Additionally, the blue light emitting device 33 may form a blue subpixel.

In such a subpixel arrangement, as indicated by a solid line, when the blue light emitting element 31 of the red subpixel emits light, the emitted light excites the red phosphor layer 21 to emit red light.

Meanwhile, as indicated by a dotted line, a portion of the light emitted from the blue light emitting device 31 may excite the green phosphor layer 22 of the neighboring green subpixel to emit green light. In addition, a blue component exists among the light that has passed through the red phosphor layer 21, and the green phosphor layer 22 can be excited by this blue component as well. This phenomenon in which unintended subpixels emit light can be referred to as a crosstalk phenomenon.

Conventionally, in order to prevent this crosstalk phenomenon, partition walls were sometimes formed between subpixels. However, not only does the number of steps increase due to the formation of such a partition, but there are also limitations in realizing resolution. Additionally, when forming a partition, problems may occur due to alignment tolerances. Meanwhile, the partition itself may be an obstacle to implementing flexibility.

However, according to an embodiment of the present invention, light emitted from one light-emitting device does not excite a neighboring light-emitting device or a phosphor layer formed on the light-emitting device, so a crosstalk phenomenon may not occur.

For example, referring again to FIG. 1, since the light emitted from the red light emitting device 310 does not include a blue component, the green phosphor layer 324 of the neighboring green light emitting device 320 may not emit light.

Since the light emitted from the green light emitting device 320 does not contain a blue component, the red phosphor layer 314 of the neighboring red light emitting device 310 may not emit light. Since the light emitted from the green phosphor layer 324 is primarily excited and emitted by the light-emitting device 324, it may not have a substantial effect on the neighboring red phosphor layer 314.

3 to 14 are cross-sectional schematic diagrams showing manufacturing steps of a display device using a semiconductor light-emitting device according to an embodiment of the present invention.

First, referring to FIG. 3, as described above, a plurality of blue light-emitting devices 311, 321, and 331 capable of emitting blue light can be divided and formed on the growth substrate 500. In other words, a COW (chip on wafer), which is a state in which a plurality of light-emitting devices are formed on a wafer, can be formed.

Among these multiple blue light-emitting devices 311, 321, and 331, a certain blue light-emitting device 311 may be formed as a red light-emitting device 310 that emits red light. The blue light-emitting device 311 that is converted to the red light-emitting device 310 may be referred to as the first blue light-emitting device 311.

In addition, among the plurality of blue light-emitting devices 311, 321, and 331, a certain blue light-emitting device 321 may be formed as a green light-emitting device 320 that emits green light. The blue light-emitting device 321 that is converted into the green light-emitting device 320 may be referred to as the second blue light-emitting device 311.

The other blue light-emitting devices 331 may remain as light-emitting devices that emit blue light. The blue light-emitting device 331, which is maintained as a light-emitting device that emits blue light, may be referred to as the third blue light-emitting device 331.

Next, an embodiment of transferring the plurality of blue light emitting devices 311, 321, and 331 to the wiring board 100 through the donor substrates 600 and 700 will be described. However, it may be directly transferred to the wiring board 100 without using the donor substrates 600 and 700. The process of directly transferring these multiple blue light-emitting devices 311, 321, and 331 to the wiring board 100 can be inferred through an embodiment of transferring them to the wiring board 100 through the donor substrates 600 and 700. Redundant explanations are omitted.

Thereafter, referring to FIG. 4 , a plurality of blue light emitting devices 311, 321, and 331 may be transferred onto the first donor substrate 600.

These multiple blue light emitting devices 311, 321, and 331 may be transferred to the first adhesive layer 610 located on the first donor substrate 600.

At this time, a plurality of blue light-emitting devices 311, 321, and 331 may be transferred onto the first donor substrate 600 by a laser lift off (LLO) process. That is, by irradiating a laser from the opposite side of the growth substrate 500 toward each of the blue light-emitting devices 311, 321, and 331, the blue light-emitting devices 311, 321, and 331 are separated from the growth substrate 500 and formed on the first donor substrate ( It may be attached to the first adhesive layer 610 of 600).

FIG. 5 shows the blue light emitting elements 311, 321, and 331 attached and transferred to the adhesive layer 610 of the first donor substrate 600.

Referring to FIG. 6, a red phosphor layer 314 may be formed on the first blue light emitting device 311. This red phosphor layer 314 may be formed by bar coating. The process of forming the phosphor layer 314 by bar coating will be described later with reference to FIGS. 18 to 21.

For convenience of explanation, FIG. 6 shows the red phosphor layer 314 formed on the top surface of the first blue light-emitting device 311. However, as shown in FIG. 1, the red phosphor layer 314 is formed on the first blue light-emitting device 311. It may be formed to cover all surfaces except the electrode of the light emitting device 311.

Next, referring to FIG. 7, a green phosphor layer 324 may be formed on the second blue light-emitting device 321. This green phosphor layer 324 can be formed by bar coating. The green phosphor layer 324 may be formed through the same process as the red phosphor layer 314.

The sequence of the process of forming the red phosphor layer 314 and the process of forming the green phosphor layer 324 may be different from that described above. For example, of course, the green phosphor layer 324 may be formed first and then the red phosphor layer 314 may be formed.

Thereafter, referring to FIG. 8, a color filter 316 may be formed on the red phosphor layer 314.

This color filter 316 may be formed on the red phosphor layer 314 to have a certain thickness. Additionally, as described above, the color filter 316 may include a blue light blocking filter. The color filter 316 may block blue light that passes through the red phosphor layer 314 without being converted, allowing the red light emitting device 310 to emit pure red light.

Next, referring to FIG. 9, a color filter 326 may be formed on the green phosphor layer 324.

This color filter 326 may be formed on the red phosphor layer 324 to have a certain thickness. Additionally, as described above, the color filter 326 may include a blue light blocking filter. The color filter 326 may block blue light that passes through the green phosphor layer 324 without being converted and allow the green light emitting device 310 to emit pure green light.

The sequence of the process of forming the color filter 316 on the red phosphor layer 314 and the process of forming the color filter 326 on the green phosphor layer 324 may be different from that described above. For example, of course, the color filter 326 may first be formed on the green phosphor layer 324 and then the color filter 316 may be formed on the red phosphor layer 314.

Next, referring to FIG. 10, a height compensation layer 334 may be formed on the third blue light emitting device 331. Redundant description of the height compensation layer 334 will be omitted. In this way, the height compensation layer 334 is formed on the third blue light-emitting device 331, so that the blue light-emitting device 330 forming the third subpixel can be formed.

As described above, the height compensation layer 334 prevents problems that may occur due to height differences between the subpixels 310, 320, and 330 during the transfer process of each subpixel 310, 320, and 330 in a later step. It can be resolved.

Referring to FIG. 11 , in a state in which the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 are formed alternately on the first donor substrate 600, the red light-emitting device 310 ), the green light emitting device 320 and the blue light emitting device 330 may be transferred to the second donor substrate 700.

This second donor substrate 700 may also include a second adhesive layer 710 formed in the transfer area so that the transfer process can be performed smoothly.

In this way, the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 may be transferred to the second adhesive layer 710 located on the second donor substrate 700.

That is, as shown in FIG. 11, after attaching the second adhesive layer 710 on the red light-emitting device 310, green light-emitting device 320, and blue light-emitting device 330, as shown in FIG. 12. The red light emitting device 310, green light emitting device 320, and blue light emitting device 330 may be separated and transferred to the second donor substrate 700.

At this time, the adhesive force of the second adhesive layer 710 may be greater than the adhesive force of the first adhesive layer 610. Therefore, as shown in FIG. 11, the first donor substrate 600 and the second donor substrate 700 are attached to both sides of the red light-emitting device 310, green light-emitting device 320, and blue light-emitting device 330, respectively, and then separated. When doing so, as shown in FIG. 12, the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 can be transferred to the second donor substrate 700.

Thereafter, referring to FIG. 13 , the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 may be transferred onto the substrate 110 of the wiring board 100.

In order to transfer the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 to the wiring board 100, the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 ) may be first transferred at a certain interval from either the first donor substrate 600 or the second donor substrate 700 and then transferred to the wiring board 100.

At this time, the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 may be electrically connected to the substrate 110. For example, the red light-emitting device 310, the green light-emitting device 320, and the blue light-emitting device 330 are electrically connected to the wiring electrode or electrode pad on the wiring board 100 by members such as solder, conductive balls, and conductive adhesive layers. can be connected

Next, as shown in FIG. 14, the second donor substrate 700 may be separated to achieve the same state as in FIG. 1.

15 to 17 are cross-sectional views showing examples of light-emitting elements of a display device using a semiconductor light-emitting element according to an embodiment of the present invention.

Referring to FIG. 15, the blue light emitting device 311 may have a patterned sapphire substrate (PSS) structure. That is, the blue light emitting device 311 may have a light extraction structure 317 formed on a sapphire substrate. This light extraction structure 317 may be formed in the opposite direction to the P-type electrode 312. Here, for convenience, the N-type electrode is omitted.

A phosphor layer 314 is formed on this light extraction structure 317 to implement a red light-emitting device 310.

Referring to FIG. 16, the blue light emitting device 311 may have a nano porus structure in which nano-sized holes 318 are formed. In this way, the phosphor layer 314 is formed on the nano-sized holes 318 to implement the red light-emitting device 310.

Meanwhile, referring to FIG. 17, a quantum dot (QD) phosphor or nanoparticle phosphor layer 315 may be formed on the nano-sized holes 318. Such QD phosphor or nanoparticle phosphor layer 315 may also be located within nano-sized holes 318.

In this way, the red light emitting device 310 having various shapes can be used. This structure of the light emitting device can be equally applied to the green light emitting device 320.

Meanwhile, as mentioned above, the formation of the red phosphor layer 314 and/or the green phosphor layer 324 involves forming a mask pattern with photo resist (PR), etc., and barcoating (bar coating) in the empty space. A method of filling the red phosphor (gap fill) with bar coating can be used.

In general, it is difficult for solids with a size of 100 nm or more, such as inorganic phosphors, to remain dispersed in a liquid phase. However, during the gap fill process, a structure may be created in which red phosphors are stacked in empty spaces without maintaining gaps.

At this time, the size of the red inorganic phosphor and/or green inorganic phosphor may be about 100 nm to 5 ㎛.

18 to 21 are cross-sectional schematic diagrams showing a manufacturing process that can be used in the process of forming a phosphor layer of a display device using a light-emitting device according to an embodiment of the present invention.

Hereinafter, with reference to FIGS. 18 to 21, the process of forming a red phosphor using a bar coating method will be briefly described as an example. For convenience of explanation, an example in which the red phosphor is formed on the flat plate 50 will be described. This explanation can be equally applied to the formation process of green phosphor.

Referring to FIG. 18, first, a mask pattern 20 may be formed on the flat plate 50. At this time, the pattern spacing of the mask pattern 20 may correspond to the size (chip size) of the blue light-emitting device 311 (chip) described above. Therefore, the formation of the phosphor layer by the bar coating method described herein can be applied equally to the phosphor formation process described above with reference to FIGS. 6 and 7.

Referring to FIG. 19 , the red phosphor layer 314 can be formed by filling a gap on the mask pattern 20 using the bar 30 with the red phosphor 318.

Thereafter, referring to FIG. 20, the phosphor 318 that fills and overflows the mask pattern 20, that is, the portion of the phosphor 318 formed higher than the height of the mask pattern 20 can be removed using the wiper 31. there is.

Next, when the mask pattern 20 is removed, a red phosphor layer 314 pattern can be formed with a certain thickness (for example, 4.5 ㎛) in a certain area, as shown in FIG. 21. The red phosphor layer 314 formed here may have substantially the same physical properties and dimensions as the red phosphor layer 314 described above with reference to FIG. 6.

The phosphor layer 314 formed by this method can show reliability that can be used as a subpixel when used as a red light source in a display device.

According to the above-described embodiment of the present invention, the red phosphor layer 314 and the green phosphor layer 324 can be efficiently formed to implement a high-resolution display through phosphor color conversion of the blue light-emitting devices 311 and 321.

Accordingly, only gallium nitride-based blue light-emitting devices 311, 321, and 331 can be used, thereby simplifying the manufacturing process.

Additionally, during the manufacturing process, the phosphor layers 314 and 324 can act as an impact cushioning layer, thereby reducing the breakage rate of the light emitting device.

In addition, during the manufacturing process, the height compensation layer 334 to match the height of the phosphor layers 314 and 324 can also serve as an impact cushioning layer, thereby further reducing the damage rate of the light emitting device.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

According to the present invention, it is possible to provide a display device using a semiconductor light-emitting device such as micro LED.

Claims (16)

In a display device using a light-emitting element, wiring board; Includes a plurality of pixels arranged on the wiring board, Each pixel is, a first subpixel including a red phosphor layer formed on a blue light emitting device; a second subpixel including a green phosphor layer formed on the blue light emitting device; and A display device using a light-emitting device, comprising a third subpixel including a blue light-emitting device. The display device according to claim 1, wherein the red phosphor layer and the green phosphor layer are formed to a certain thickness on the blue light emitting device. The display device according to claim 1, further comprising a light-shielding layer positioned between each pixel on the wiring board. The display device according to claim 1, wherein the third subpixel includes a height compensation layer located on the blue light emitting device. The display device of claim 4, wherein the height compensation layer compensates for a height difference between the third subpixel, the first subpixel, and the second subpixel. The display device according to claim 1, wherein the first subpixel further includes a color filter located on the red phosphor layer. The display device according to claim 6, wherein the color filter includes a blue light blocking filter. The display device according to claim 1, wherein the second subpixel further includes a color filter located on the green phosphor layer. In a method of manufacturing a display device using a light-emitting element, Transferring a plurality of blue light-emitting devices grown and divided on a growth substrate onto a first donor substrate; forming a red phosphor layer on a first blue light emitting device forming a first subpixel among the blue light emitting devices located on the donor substrate; forming a green phosphor layer on a second blue light emitting device forming a second subpixel among the blue light emitting devices located on the donor substrate; forming a color filter on the red phosphor layer and the green phosphor layer; transferring the first blue light-emitting device, the second blue light-emitting device, and the three blue light-emitting devices forming a third subpixel onto a second donor substrate; and A method of manufacturing a display device using a light-emitting device, comprising the step of transferring the first blue light-emitting device, the second blue light-emitting device, and the third blue light-emitting device onto a wiring board. The method of claim 9, wherein forming the red phosphor layer comprises: A method of manufacturing a display device using a light-emitting device, characterized in that a red phosphor layer having a certain thickness is locally formed on the first blue light-emitting device. The method of claim 9, wherein forming the green phosphor layer comprises: A method of manufacturing a display device using a light-emitting device, characterized in that a green phosphor layer having a certain thickness is locally formed on the second blue light-emitting device. The method of manufacturing a display device using a light-emitting device according to claim 9, further comprising forming a height compensation layer on the three blue light-emitting devices after forming the color filter. The method of claim 12, wherein the height compensation layer compensates for a height difference between the first subpixel, the second subpixel, and the third subpixel. The method of claim 12, wherein the height compensation layer acts as an impact cushioning layer during the transfer process. The method of claim 9, wherein forming the red phosphor layer comprises: A method of manufacturing a display device using a light-emitting device, comprising the step of performing bar coating on a mask pattern masking the second blue light-emitting device and the third blue light-emitting device. The method of claim 9, wherein forming the green phosphor layer comprises: A method of manufacturing a display device using a light-emitting device, comprising the step of performing bar coating on a mask pattern masking the first blue light-emitting device and the third blue light-emitting device.

Images