KR20190117968A - Display apparatus and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a display device and a method for manufacturing the same and, more specifically, to a large-area display device using a light emitting diode (LED) having a micro-unit size and a method for manufacturing the same. A display device according to an embodiment of the present invention comprises: a substrate for a display panel; and a plurality of light emitting parts arranged in an array form on the substrate, wherein each of the light emitting parts includes a metal layer which is arranged on the substrate, a light emitting cell which is arranged on the metal layer and emits light having different wavelengths, and a driving part which is arranged on the substrate and electrically drives the light emitting cell. The light emitting cell includes a first conductive semiconductor layer which is arranged on the metal layer as a common layer, a plurality of active layers which are spaced apart from each other on one plane of the first conductive semiconductor layer and emit light having a specific wavelength, a second conductive semiconductor layer which is arranged on each of the active layers, and a wavelength conversion layer which is arranged on the second conductive semiconductor layer.

Description

Display apparatus and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a method for manufacturing the same, and more particularly, to a display device having a large area and a method for manufacturing the same using a light emitting diode (LED) having a micro unit size.

A light emitting diode (LED) is one of light emitting devices that emit light when a current is applied. Light emitting diodes can emit high-efficiency light at low voltage, resulting in excellent energy savings. Recently, the luminance problem of the light emitting diode has been greatly improved, and has been applied to various devices such as a backlight unit, a display board, a display, and a home appliance of a liquid crystal display.

Recently, display devices using light emitting diodes have been actively developed. Most display device technologies use three light emitting diode (red, green, blue) chips to implement one pixel. In this case, there is a difficulty in configuring the same driving circuit because the driving current is different for each chip. In addition, different types of light emitting diode chips have different types of light emitting parts, and thus, each chip has a different lifetime.

Micro light emitting diodes (μ-LEDs) are very small, ranging in size from 5 to 200 μm, and more than 25 million pixels are required to implement a 40-inch display device. Therefore, there is a problem in that it takes at least one month in time for a simple pick and place method to make a single 40-inch display device.

The present invention has been made to solve the problems of the prior art, the problem to be solved by the present invention is to provide a light emitting diode display device and a method of manufacturing the same.

In addition, an object of the present invention is to provide a method of manufacturing a light emitting diode display device that does not require a process such as pick & place, transfer and soldering.

In addition, the problem to be solved of the present invention, the pixel array unit including a plurality of semiconductor driving circuit, the pixels are transferred to the display panel, so the light emission is much faster than the pick-and-place process of the LED chip unit Provided is a diode manufacturing method.

In addition, the problem to be solved of the present invention, since the pixel including a plurality of light emitting diodes are manufactured using one kind of light emitting diode, it is possible to drive the plurality of light emitting diodes under the same conditions, so that the light emission is improved reliability Provided are a diode display device and a method of manufacturing the same.

The problem to be solved of the present invention is not limited to the above-mentioned problems, and other tasks not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

A display device according to an embodiment of the present invention includes a substrate; And a plurality of light emitting parts arranged in an array form on the substrate, wherein each of the plurality of light emitting parts comprises: a metal layer disposed on the substrate; A light emitting cell disposed on the metal layer and emitting light of different wavelengths; And a driving unit disposed on the metal layer and electrically driving the light emitting cell, wherein the light emitting cell comprises: a first conductive semiconductor layer disposed as a common layer on the metal layer; A plurality of active layers spaced apart from each other on one plane on the first conductive semiconductor layer and emitting light of a specific wavelength; A second conductivity type semiconductor layer disposed on each of the plurality of active layers; And a wavelength conversion layer disposed on the second conductivity type semiconductor layer.

In the method of manufacturing a display device according to an embodiment of the present invention, a light emitting structure formed on a growth substrate is divided into a plurality of separated light emitting structures corresponding to a plurality of light emitting units, and each of the separated light emitting structures is divided into a plurality of light emitting regions. Separating step of separating; A driving unit forming step of forming driving units for each of the light emitting regions on one side of the separated light emitting structure as the growth substrate; A peeling step of peeling the growth substrate from the light emitting structure and the driving part; A metal layer forming step of forming a metal layer under the light emitting structure and the driving unit; Forming a wavelength conversion layer on all or part of the plurality of light emitting regions; Dicing the light emitting structure in a pixel array unit including at least two light emitting units of the plurality of light emitting units; And a substrate bonding step of bonding the plurality of light emitting units to the display panel substrate in the pixel array unit.

According to still another aspect of the present invention, there is provided a method of manufacturing a display apparatus, the method including: dicing a plurality of light emitting units arranged in an array form on a metal layer in a pixel array unit including at least two light emitting units; And attaching the diced pixel array onto a display substrate, wherein each of the plurality of light emitting parts comprises: a light emitting cell disposed on a metal layer and emitting light having a different wavelength; And a driving unit disposed on the metal layer and electrically driving the light emitting cell, wherein the light emitting cell comprises: a first conductive semiconductor layer disposed as a common layer on the metal layer; A plurality of active layers spaced apart from each other on one plane on the first conductive semiconductor layer and emitting light of a specific wavelength; A second conductivity type semiconductor layer disposed on each of the plurality of active layers; And a wavelength conversion layer disposed on the second conductivity type semiconductor layer.

Using the display device according to the embodiment of the present invention, one pixel may be implemented as one or a plurality of light emitting cells having a size of micro units.

In addition, the use of the display device according to the embodiment of the present invention has an advantage that a large-area display device can be easily obtained.

In addition, the use of the display device according to the embodiment of the present invention has an advantage in that light emitting cells emitting light of different wavelengths in one pixel can be driven under the same conditions. Therefore, the driving circuit and the driving conditions are simple and the reliability is the same.

When using the manufacturing method of the display device according to the embodiment of the present invention, since the pixels are formed on the display substrate in units of a pixel array including a plurality of pixels, a separate chip pick and place process is not required. . Therefore, there is an advantage that the display device can be implemented regardless of the size and number of light emitting structures.

In addition, when the manufacturing method of the display device according to the embodiment of the present invention is used, since a plurality of light emitting parts are adhered to the substrate of the display in pixel array units, soldering for soldering the finished light emitting diodes to the substrate, etc. The process has no advantage.

1 is a plan view of a display device according to an embodiment of the present invention.
FIG. 2 is an enlarged view illustrating one light emitting unit 300 of the display device illustrated in FIG. 1.
3 is a cross-sectional view taken along the line AA ′ of the display device illustrated in FIG. 2.
FIG. 4 is a cross-sectional view taken along line BB ′ of the display device illustrated in FIG. 2.
FIG. 5 is a perspective view of a part of the display apparatus shown in FIG. 1. FIG.
6A to 6I are process diagrams for describing a method of manufacturing a display apparatus according to an exemplary embodiment of the present invention illustrated in FIGS. 1 to 5.

In the description of the embodiments, when described as being formed on the "top" or "bottom" of each component, the top (bottom) or the bottom (bottom) is the two components are in direct contact with each other. Or one or more other components disposed between and formed between the two components. In addition, when expressed as "up (up) or down (down)" may include the meaning of the down direction as well as the up direction based on one component.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1 is a plan view of a display device according to an embodiment of the present invention, FIG. 2 is an enlarged view of one light emitting unit 300 of the display device shown in FIG. 1, and FIG. 3 is shown in FIG. 2. 4 is a cross-sectional view of the display device taken along line AA ′, and FIG. 4 is a cross-sectional view of the display device shown in FIG. 2 taken along line B-B ′, and FIG. 5 is a perspective view of a portion of the display device shown in FIG. 1.

Referring to FIG. 1, a display apparatus according to an exemplary embodiment of the present disclosure may include a substrate 100 and a plurality of light emitting units 300 disposed on the substrate 100. The plurality of light emitters 300 may be adhered to the substrate 100 in a pixel array 400 unit.

The substrate 100 may be a material capable of transmitting all or part of light. For example, the substrate 100 may be a glass substrate, or may be a plastic substrate.

The substrate 100 may be one of a flexible film, a metal printed circuit board (PCB), and a ceramic PCB.

The substrate 100 includes an upper surface 110 and a lower surface. A plurality of light emitting parts 300 may be disposed on the top surface 110 of the substrate 100. The upper surface 110 and the lower surface of the substrate 100 may have a large area. For example, the diagonal length of the top surface 110 may be several tens of inches.

The substrate 100 may be a planar substrate or a curved substrate. When the substrate 100 is a flat substrate, the upper surface 110 of the substrate 100 may be a flat surface. Meanwhile, when the substrate 100 is a curved substrate, the upper surface 110 of the substrate 100 may include a curved surface in which all or part of the substrate 100 is curved.

The substrate 100 may be a rigid material or may be a flexible material.

The substrate 100 may be a substrate for a display panel of the display device according to an embodiment of the present invention.

The plurality of light emitting parts 300 are disposed on the substrate 100. In detail, the plurality of light emitting parts 300 may be disposed on the upper surface 110 of the substrate 100.

The plurality of light emitters 300 may be arranged in an array form on the top surface 110 of the substrate 100. The plurality of light emitting parts 300 may be arranged in predetermined rows and columns on the upper surface 110 of the substrate 100.

In FIG. 1, a first pixel array 400-1 including a plurality of light emitters 300 and a second pixel array 400-2 including a plurality of light emitters 300 are illustrated. In FIG. 1, each pixel array 400 is illustrated as including a plurality of light emitting units 300 spaced apart from each other in a horizontal direction (row), but according to an embodiment, the pixel array 400 may be arranged in a vertical direction (column). ) May include a plurality of light emitting parts 300 spaced apart from each other, or may include a plurality of light emitting parts 300 spaced apart from each other in a horizontal direction (row) and a vertical direction (column). Alternatively, according to an embodiment, each pixel array may include a plurality of light emitting parts 300 arranged in different shapes.

In FIG. 1, the plurality of light emitters 300 included in one pixel array 400-1 and 400-2 may include a common metal layer 200. The metal layer 200 of the first pixel array 400-1 and the metal layer 200 of the second pixel array 400-2 may be separated from each other.

Each of the plurality of light emitters 300 may constitute one pixel. That is, the plurality of light emitters 300 may be referred to as a plurality of pixels. A detailed structure of one pixel, that is, one light emitting unit 300 will be described with reference to FIGS. 2 to 4.

2 to 4, one light emitting unit 300 may include a light emitting cell 310 and a driving unit 350a, 350b, 350c. The light emitting unit 300 may further include a metal layer 200 positioned below the light emitting cell 310 and a metal pad 210 positioned above the light emitting cell 310.

The metal layer 200 is disposed on the substrate 100. The light emitting cells 310 are disposed on the metal layer 200 and emit light of different wavelengths. Here, the light emitting cell 310 may emit light of three or more different wavelengths.

The light emitting cell 310 has a plurality of light emitting regions 310a, 310b, 310c that emit light of different wavelengths.

The plurality of light emitting regions 310a, 310b, and 310c may include a first light emitting region 310a, a second light emitting region 310b, and a third light emitting region 310c. Here, the number of light emitting regions 310a, 310b, 310c is not limited to three as shown in the drawing. In some cases, the plurality of light emitting regions may be two or four, or five or more.

The plurality of light emitting regions 310a, 310b, and 310c may be arranged in one column on the metal layer 200. However, the present invention is not limited thereto, and the plurality of light emitting regions 310a, 310b, and 310c may be arranged on the substrate 100 in a predetermined matrix (eg, 2 * 2 matrix).

The size of each light emitting area 310a, 310b, 310c may correspond to the size of the micro light emitting diode. For example, the size of each emission region 310a, 310b, 310c may be 5 to 200 μm.

The light emitting cell 310 may emit light of various colors. Specifically, light of a red wavelength is emitted from the first light emitting area 310a included in the light emitting cell 310, light of a green wavelength is emitted from the second light emitting area 310b, and third light emitting area 310c. Light of the blue wavelength may be emitted.

The light emitting unit 300 includes a plurality of driving units 350a, 350b, and 350c. The plurality of driving units 350a, 350b, and 350c may control the light emission of the plurality of light emitting regions 310a, 310b, and 310c. The plurality of driving units 350a, 350b, and 350c may correspond one-to-one with the plurality of light emitting regions 310a, 310b, and 310c. That is, one driving unit 350a may control the driving of one light emitting region 310a. In detail, the plurality of driving units 350a, 350b, and 350c may include the first driving unit 350a for controlling the driving of the first light emitting area 310a and the second driving unit for controlling the driving of the second light emitting area 310b. And a third driver 350c for controlling the driving of the 350b and the third light emitting region 310c. Here, the number of the plurality of driving units may be two or four, may be five or more.

Each of the plurality of driving units 350a, 350b, and 350c may be a semiconductor driving circuit including a thin film transistor (TFT). The TFT may be electrically connected to the adjacent light emitting cells 310 through the metal layer 200 and the metal pad 210, and may control driving of the adjacent light emitting cells 310 according to an external control signal.

The first driver 350a to the third driver 350c may be disposed on the metal layer 200 and may be disposed adjacent to the light emitting cell 310. More specifically, the first driver 350a may be disposed on the metal layer 200 and may be disposed adjacent to one side of the first light emitting region 310a of the light emitting cell 310. The second driver 350b may be disposed on the metal layer 200 and may be disposed adjacent to one side of the second light emitting region 310b of the light emitting cell 310. The third driver 350c may be disposed on the metal layer 200, and may be disposed adjacent to one side of the third light emitting region 310c of the light emitting cell 310.

The first driving unit 350a to the third driving unit 350c may be electrically connected to the first to third light emitting regions 310a, 310b and 310c to drive the first to third light emitting regions 310a, 310b and 310c. have. More specifically, the first driver 350a may be electrically connected to the first emission region 310a through the metal layer 200 and the electrode pad 210a. The second driver 350b may be electrically connected to the second light emitting region 310b through the metal layer 200 and the electrode pad 210b. The third driver 350c may be electrically connected to the third light emitting region 310c through the metal layer 200 and the electrode pad 210c.

A detailed stacked structure of the light emitting cells 310 will be described. As shown in FIGS. 3 to 4, the light emitting cell 310 has a plane on the first conductive semiconductor layer 301 and the first conductive semiconductor layer 301 which are disposed as a common layer on the metal layer 300. A plurality of active layers 302a, 302b, and 302c spaced apart from one another and emitting light of a specific wavelength on the second conductive semiconductor layers 303a, 303b, and 303c disposed on the respective active layers 302a, 302b, and 302c. And a plurality of wavelength conversion layers 304a, 304b, and 304c disposed on each of the second conductivity type semiconductor layers 303a, 303b, and 303c. Here, the number of active layers 302a, 302b, and 302b may correspond to the number of light emitting regions 310a, 310b, and 310c. In addition, the number of the second conductive semiconductor layers 303a, 303b, and 303c may also correspond to the number of the light emitting regions 310a, 310b, and 310c.

The first conductivity type semiconductor layer 301 may be disposed on the metal layer 200. The metal layer 200 may be disposed on the top surface 110 of the substrate 100. Here, a predetermined adhesive layer (not shown) may be disposed between the metal layer 200 and the upper surface 110 of the substrate 100. Here, the adhesive layer may be any one of a conductive epoxy, a conductive silicone, a conductive adhesive, a conductive film, and a metal paste.

In the light emitting cell 310, the first conductivity type semiconductor layer 301 may be configured as one. However, the present invention is not limited thereto, and in some cases, the first conductive semiconductor layer 301 may be two or more in the light emitting cell 310, and may be configured to be smaller than the number of the active layers and / or the second conductive semiconductor layers. have.

The first conductive semiconductor layer 301 is formed of n-type Al _x In _y Ga _1-xy N (0 = x, y, x + y ≦ = 1), and is formed of a nitride semiconductor doped with n-type impurities. Can be. For example, impurities such as Si, Ge, Se, Te, or C are doped into nitride semiconductors such as GaN, AlGaN, InGaN. The first conductivity type semiconductor layer 301 may be disposed in a single layer or multiple layers.

Although not illustrated in a separate drawing, the first conductivity-type semiconductor layer 301 may further include a current spreading layer or an ohmic layer. The current spreading layer may serve to diffuse current injected through the electrode, and the ohmic layer may serve to facilitate ohmic contact with the electrode.

A plurality of active layers 302a, 302b, and 302c may be disposed on the first conductive semiconductor layer 301. The plurality of active layers 302a, 302b, and 302c may be disposed on the upper surface of the first conductivity type semiconductor layer 301 at predetermined intervals from each other. Here, the number of the active layers 302a, 302b, and 302c may correspond to the number of the light emitting regions 310a, 310b, and 310c. That is, the first active layer 302a is disposed under the first emission area 310a, the second active layer 302b is disposed under the second emission area 310b, and the first active layer 302b is disposed under the third emission area 310c. 3 active layers can be arranged.

The plurality of active layers 302a, 302b, and 302c are disposed apart from each other, but may have the same material and structure. Thus, the specific wavelengths of light emitted from the plurality of active layers 302a, 302b, 302c may be the same. For example, light of a blue wavelength may be emitted from the plurality of active layers 302a, 302b, and 302c. However, the present invention is not limited thereto, and the plurality of active layers 302a, 302b, and 302c may emit one of green wavelength light, red wavelength light, white wavelength light, and ultraviolet wavelength light.

Each active layer 302a, 302b, or 302c has electrons (or holes) injected through the first conductive semiconductor layer 301 and holes (or electrons) injected through the second conductive semiconductor layers 303a, 303b, and 303c. ) Meet each other and emit light due to a band gap difference depending on a material of the active layers 302a, 302b, and 302c.

Each active layer 302a, 302b, or 302c has a single well, a single quantum well, a multiple well, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. It may be formed of at least one.

Each active layer 302a, 302b, 302c may be implemented with a compound semiconductor. The active layer 302 may be implemented by at least one of a group II-VI and a group III-V compound semiconductor, for example.

Each of the active layers 302a, 302b, and 302c includes a plurality of well layers and a plurality of barrier layers alternately arranged, and a pair of well layers / barrier layers may be formed in 2 to 30 cycles. The period of the well layer / barrier layer is, for example, AlInGaP / AlInGaP, InGaN / GaN, GaN / AlGaN, AlGaN / AlGaN, InGaN / AlGaN, InGaN / InGaN, AlGaAs / GaAs, InGaAs / GaAs, InGaP / GaP, AlInGaP / At least one of InGaP, or a pair of InP / GaAs. The well layer may be disposed of a semiconductor material having a composition formula of InxAlyGa1-x-yP (0 <x = 1, 0 ≦ = y ≦ = 1, 0 ≦ = x + y <1). The barrier layer may be formed of a semiconductor material having a composition formula of InxAlyGa1-x-yP (0 = x ≦ = 1, 0 ≦ = y ≦ = 1, 0 ≦ = x + y <1).

Second conductive semiconductor layers 303a, 303b, and 303c may be disposed on each of the plurality of active layers 302a, 302b, and 302c. The second conductive semiconductor layers 303a, 303b, and 303c are also formed in the light emitting cell 310. One second conductive semiconductor layer 303a, 303b, or 303c may be disposed on one active layer 302a, 302b, or 302c. The plurality of second conductivity type semiconductor layers 303a, 303b, and 303c may be disposed on the top surfaces of the active layers 302a, 302b, and 302c, and may be disposed to be spaced apart from each other by a predetermined distance, like the plurality of active layers 302a, 302b, and 302c. . In each of the emission regions 310a, 310b, and 310c, one second conductive semiconductor layer and one active layer are disposed.

Each second conductive semiconductor layer 303a, 303b, or 303c is formed of p-type Al _x In _y Ga _1-xy N (0 = x, y, x + y ≦ = 1), which is doped with p-type impurity. It may be made of a semiconductor material. For example, an impurity such as magnesium (Mg), zinc (Zn), beryllium (Be), or the like is doped into a nitride semiconductor such as GaN, AlGaN, or InGaN.

Each second conductive semiconductor layer 303a, 303b, or 303c may be arranged in a single layer or multiple layers. The second conductive semiconductor layers 303a, 303b, and 303c may be formed in a superlattice structure in which at least two different layers are alternately arranged.

Although not illustrated in a separate drawing, the second conductivity-type semiconductor layers 303a, 303b, and 303c may further include a current spreading layer or an ohmic layer. The current spreading layer may serve to diffuse current injected through the electrode, and the ohmic layer may serve to facilitate ohmic contact with the electrode.

The wavelength conversion layers 304a, 304b, and 304c may be disposed on each of the plurality of second conductivity type semiconductor layers 303a, 303b, and 303c. Therefore, the wavelength conversion layers 304a, 304b, and 304c also form a large number. The number of wavelength conversion layers 304a, 304b and 304c may correspond to the number of light emitting regions 310a, 310b and 310c or may be smaller than the number of light emitting regions 310a, 310b and 310c.

Top surfaces of each of the plurality of wavelength conversion layers 304a, 304b, and 304c may correspond to the light emitting regions 310a, 310b, and 310c, respectively.

Meanwhile, the wavelength conversion layer may not be present in one of the plurality of light emitting regions 310a, 310b, and 310c. For example, when the wavelength of light emitted from the plurality of active layers 302a, 302b, and 302c is a blue wavelength, the first wavelength conversion layer 304a is red by the blue wavelength of light emitted from the first active layer 302a. It may have a red phosphor to emit light of the wavelength, the second wavelength conversion layer 304b has a green phosphor to emit light of the green wavelength by the light of the blue wavelength emitted from the second active layer 302b. Can be. However, the wavelength conversion layer may not be disposed on the third active layer 302c. Therefore, the light emitted from the third active layer 302c may be emitted as it is in the third emission region 310c.

In some cases, the wavelength conversion layer may be formed in all of the emission regions 310a, 310b, and 310c. For example, the first wavelength conversion layer 304a may have a red phosphor to emit light of a red wavelength, and the second wavelength conversion layer 304b may have a green phosphor to emit light of a green wavelength. have. The third wavelength conversion layer 304c may have a blue phosphor to emit light having a blue wavelength.

Also, in some cases, the first wavelength conversion layer 304a may have a first red phosphor to emit light of a first red wavelength, and the second wavelength conversion layer 304b may have light of a second red wavelength. The third wavelength conversion layer 304c may have a green phosphor to emit light of a green wavelength, and the additional wavelength conversion layer (not shown) may have a blue wavelength to emit light. It may have a blue phosphor to emit light.

The plurality of wavelength conversion layers 304a, 304b, and 304c may include a quantum dot phosphor or a yag phosphor.

The quantum dot phosphor may include a red quantum dot phosphor that emits light of a red wavelength, a green quantum dot phosphor that emits light of a green wavelength, and a blue quantum dot phosphor that emits light of a blue wavelength. The quantum dot phosphors included in the wavelength conversion layers 304a, 304b, and 304c may be determined according to wavelengths of light emitted from the emission regions 310a, 310b, and 310c. The same is true for yag phosphors.

2 to 4, the plurality of light emitting regions 310a, 310b, and 310c in one light emitting cell 300 have the metal layer 200 and the first conductive semiconductor layer 301 as common layers. The active layers 302a, 302b, and 302c, the second conductive semiconductor layers 303a, 303b, and 303c, and the wavelength conversion layers 304a, 304b, and 304c are separated into a plurality.

The first driving unit 350a to the third driving unit 350c may be electrically connected to the first to third light emitting regions 310a, 310b and 310c to drive the first to third light emitting regions 310a, 310b and 310c. have. More specifically, the first driver 350a is electrically connected to the first conductive semiconductor layer 301a through the metal layer 200 and electrically connected to the second conductive semiconductor layer 303a through the electrode pad 210a. Can be connected. The second driver 350b may be electrically connected to the first conductive semiconductor layer 301b through the metal layer 200, and may be electrically connected to the second conductive semiconductor layer 303b through the electrode pad 210b. The third driver 350c may be electrically connected to the first conductive semiconductor layer 301c through the metal layer 200, and may be electrically connected to the second conductive semiconductor layer 303c through the electrode pad 210c.

Each of the metal layer 200 and the metal pads 210a, 201b, and 210c is made of a metal material of any one of copper (Cu), silver (Ag), and gold (Au), and has a thickness ranging from 10 μm to 100 μm. It can be formed as.

FIG. 5 is a perspective view of a part of the display apparatus shown in FIG. 1. FIG. In detail, FIG. 5 illustrates a plurality of light emitting parts 300-1, 300-2, and 300 that are included in one column in the first pixel array 400-1 disposed on the substrate 100 in the display device of FIG. 1. -3) is a perspective view. In FIG. 5, three light emitting units 300-1, 300-2, and 300-3 are included in the first pixel array 400-1, but the present invention is not limited thereto. It may be included in the pixel array 400-1.

In this case, the metal layer 200 may be formed as a common layer for the light emitting parts 300-1, 300-2, and 300-3 included in one pixel array 400-1. When the plurality of light emitting units are bonded to the substrate 100 in a pixel array unit, the metal layer 200 is bonded to the substrate 100 instead of directly attaching the light emitting units to the substrate 100, so that a process such as soldering is not required. Can be.

6A to 6I are process diagrams for describing a method of manufacturing a display apparatus according to an exemplary embodiment of the present invention illustrated in FIGS. 1 to 5.

Referring to FIG. 6A, the light emitting structure 320 is formed on the growth substrate 10 for epitaxial growth. Here, the light emitting structure 320 may include a first conductive semiconductor layer 301, an active layer 302, and a second conductive semiconductor layer 303. Herein, the light emitting structure 320 may be referred to as an epitaxial layer or an epitaxial layer.

Specifically, the first conductive semiconductor layer 301, the active layer 302, and the second conductive semiconductor layer 303 are sequentially formed on the upper surface of the growth substrate 10. Specifically, the first conductive semiconductor layer 301, the active layer 302, and the second conductive semiconductor layer 303 are sequentially grown on the top surface of the growth substrate 10.

The growth substrate 10 may be a sapphire substrate. In addition, the growth substrate 10 may be a patterned sapphire substrate (PSS) or nano-PSS. Growing the first conductivity-type semiconductor layer 301 on the PSS or nano-PSS, compared to the growth of the first conductivity-type semiconductor layer 301 in the flat plane of the general sapphire substrate (crystal defects (due to the deflection of the defect during growth) Reduction and total internal reflection can increase the light efficiency.

Here, a buffer layer may be formed on the upper surface of the growth substrate 10 before the first conductive semiconductor layer 301 is formed on the upper surface of the growth substrate 10. After forming the buffer layer, forming the first conductive semiconductor layer 301 on the buffer layer can mitigate lattice mismatch between the growth substrate 10 and the first conductive semiconductor layer 301.

After forming the light emitting structure 320 on the growth substrate 10, as shown in Figure 6b, by etching the light emitting structure 320, a plurality of light emitting parts (300-1, 300-2, 300-3) A plurality of separated light emitting structures 320-1, 320-2, and 320-3 corresponding to the same are separated. The first conductive semiconductor layer 301, the active layer 302, and the second conductive semiconductor layer 303 are all etched to define a plurality of separate light emitting structures 320-1, 320-2, and 320-2. Can be. Accordingly, a plurality of light emitting parts 300-1, 300-2, and 300-3 may be defined.

Referring to FIG. 6B, in the light emitting structure 320, the first conductive semiconductor layer 3010, the active layer 302, and the second conductive semiconductor layer 303 may be formed of the plurality of light emitting units 300 shown in FIG. 1. The plurality of first conductivity type semiconductor layers 301, the active layers 302, and the second conductivity type semiconductor layers 303 may be formed by separating them according to the number.

In addition, each of the separated light emitting structures 320-1, 320-2, and 320-3 may be divided into a plurality of light emitting regions 310a, 310b, and 310c. Unlike defining the light emitting part, only the active layer 302 and the second conductive semiconductor layer 303 may be etched without defining the light emitting regions 310a, 310b, and 310c. (See FIG. 4). One separate light emitting structure 320-1, 320-2, and 320-3 includes the first conductive semiconductor layer 301 in common, and each of the active layers 302a, 302b, and 302c and the second conductive semiconductor. It may be divided into a plurality of light emitting regions 310a, 310b, and 310c including the layers 303a, 303b, and 303c.

As a method of separating the light emitting structure 320 into a plurality of light emitting parts 300-1, 300-2, and 300-3 and a plurality of light emitting regions 310a, 310b, and 310c, semiconductor dry etching is typically performed. There is.

Here, in the case of defining a plurality of light emitting regions 310a, 310b, 310c included in one separated light emitting structure 320-1, 320-2, 320-3, the active layer 302 and the second conductive semiconductor The layer 303 is etched but the first conductivity type semiconductor layer 301 should not be etched. A process of separating the separated light emitting structures 320, that is, the second conductive semiconductor layer 303 and the active layer 302, respectively, the plurality of second conductive semiconductor layers 303a, 303b, and 303c and the plurality of active layers 302a. In the process of separating into 302b and 302c, a predetermined scratch, for example, a trench may be formed on the first conductive semiconductor layer 301.

Each of the separated light emitting structures 320-1, 320-2, and 320-3 includes a plurality of light emitting regions 310a, 310b, and 310c.

After separating the light emitting structure 320 to form a plurality of separate light emitting structures (320-1, 320-2, 320-3) and a plurality of light emitting regions (310a, 310b, 310c), as shown in Figure 6c Likewise, a plurality of driving units 350-1, 350-2, and 350-3 are formed on the growth substrate 10. In this case, each of the driving units 350-1, 350-2, and 350-3 corresponding to each of the separated light emitting structures 320-1, 320-2, and 320-3 may include a plurality of driving units 350a, 350b, and 350c. ). The driving units 350a, 350b, and 350c corresponding to each of the emission regions 310a, 310b, and 310c may be formed.

As shown in FIG. 6C, the metal pads 210-electrically connecting the separated light emitting structures 320-1, 320-2, and 320-3 to the driving units 350-1, 350-2, and 350-3. 1, 210-2, and 210-3 may be formed on the second conductivity type semiconductor layer 303 and the driving units 350-1, 350-2, and 350-3.

After the light emitting structure 320 and the driving unit 350 are formed, the growth substrate 10 is peeled from the light emitting structure and the driving unit 350 as shown in FIG. 6D. The growth substrate 10 may be separated from the light emitting structure 300 and the driving unit 350 by using a laser lift off (LLO) method or a chemical lift-off (CLO) method. have. Here, the method of peeling off the growth substrate 10 is not limited to LLO or CLO, and the growth substrate 10 may be peeled off using other various methods. In some embodiments, equipment such as a jig (not shown) may be used to peel off the growth substrate 10.

After peeling the growth substrate 10 from the light emitting structure 320 and the driving unit 350, as shown in FIG. 6E, the metal layer 200 is formed under the light emitting structure 320 and the driving unit 350. The metal layer 200 may be formed under the light emitting structure 320 and the driver 350 by a deposition method. According to an embodiment, the metal layer 200 may be formed in any suitable manner. The metal layer 200 may be formed to a thickness of 10 ~ 100μm.

After the metal layer 200 is formed below the light emitting structure 320 and the driving unit 350, as shown in FIG. 6F, the wavelength conversion layer 304a is disposed on all or part of the plurality of light emitting regions 310a, 310b, and 310c. , 304b, 304c). Specifically, the first wavelength conversion layer 304a is formed on the first emission area 310a among the plurality of emission areas 310a, 310b, and 310c, and the second wavelength conversion layer is formed on the second emission area 310b. 304b is formed, and a third wavelength conversion layer 304c is formed on the third light emitting region 310c. The formation of the wavelength conversion layer 304 may be performed for the plurality of light emitting parts 300-1, 300-2, and 300-3.

The plurality of wavelength conversion layers 304a, 304b, and 304c may have a predetermined quantum dot. The plurality of wavelength conversion layers 304a, 304b, and 304c may be formed on the light emitting regions 310a, 310b, and 310c by printing or dispensing a phosphor solution containing quantum dots and silicon. . In addition, the plurality of wavelength conversion layers 304a, 304b, and 304c may have a predetermined YAG phosphor.

Here, the wavelength conversion layers 304a, 304b, and 304c may not be formed on any one of the plurality of light emitting regions 310a, 310b, and 310c (not shown). For example, when the wavelength of light to be emitted in the light emitting region is the wavelength of light emitted from the active layer in the light emitting region, the wavelength conversion layers 304a, 304b and 304c may not be formed on the light emitting region.

In FIGS. 6A to 6E, a process has been described with reference to a cross-sectional view of the first pixel array 400-1 for convenience. However, according to the process of the present embodiment, a large area pixel array arranged in a plurality of rows and a plurality of columns may be manufactured. Can be. 6F is a perspective view of the light emitting structure after forming the wavelength conversion layer 304 after the process steps of FIGS. 6A to 6E.

After forming the wavelength conversion layer 304, as shown in FIG. 6G, the light emitting structure 320, the wavelength conversion layer 304, the driver 350, and the metal layer 200 are covered with the protective layer 500. Encapsulation process is performed. The encapsulation process may be performed to manufacture a display device according to an exemplary embodiment of the present invention illustrated in FIGS. 1 and 5.

The protective layer 500 may encapsulate the light emitting structure 320, the wavelength conversion layer 304, the driving unit 350, and the metal layer 200 to protect them from external foreign matter or impact. Here, the protective layer 500 may be formed of an organic material or an inorganic material. The protective layer 500 may be silicon or epoxy. The designation may be silicon nitride (SiNx) or silicon oxide (SiOx).

The passivation layer 500 may be disposed between the plurality of active layers 302a, 302b, and 302c spaced apart from each other and between the plurality of second conductive semiconductor layers 303a, 303b, and 302c spaced apart from each other. have. In addition, the protective layer 500 may be disposed between the plurality of driving units 350a, 350b, and 350c. In addition, the protective layer 500 may cover the metal layer 200 and be disposed between the light emitting units 300.

After forming the protective layer 500, as shown in FIG. 6H, the light emitting structure includes a plurality of pixel arrays including a plurality of light emitting parts 300. The light emitting structure may be diced by a predetermined unit to form a plurality of pixel bars including a plurality of light emitting parts. Each of these pixel bars may be referred to as a pixel array. In FIG. 6H, the first pixel array 400-1 includes a plurality of light emitters 300 arranged in a first column, and the second pixel array 400-2 includes a plurality of light emitters 300 arranged in a second column. It is illustrated that the light emitting structure is diced to include). In FIG. 6H, the dicing direction is indicated by the dotted line and the arrow as the horizontal direction. However, the present invention is not limited thereto, and the dicing direction may be a vertical direction, and may be performed in any direction according to the embodiment. In addition, the diced unit pixel array may include any area and / or number of light emitters.

In FIG. 6H, the light emitting structure includes a first pixel array 400-1 formed in a first column and a second pixel array 400-2 formed in a second column. However, according to an exemplary embodiment, each pixel array may be predetermined. A plurality of light emitting units arranged in rows X columns of may be included. Alternatively, the light emitting unit may include a plurality of light emitting units arranged in different forms according to the embodiment.

Each pixel array 400-1 and 400-2 includes a plurality of light emitters 300 and a driver 350, and a plurality of light emitters included in each pixel array 400-1 and 400-2. 300 has a common metal layer 200. To this end, when dicing the light emitting structure 320 may be cut together to the lower metal layer. In this case, each light emitting unit 300 may have a vertical chip shape, and thus may be suitable for use as a pixel in a display panel.

After the dicing process, each of the separated pixel arrays 400-1 and 400-2 is adhered to the display panel substrate 100 in a pixel array unit. Specifically, the pixel arrays 400-1 and 400-2 are positioned on the substrate 100, and the pixel arrays 400-1 and 400-2 are mounted on the substrate 100 using, for example, an adhesive layer (not shown). It may be attached to the upper surface (110). Here, the adhesive layer may be disposed between the metal layer 200 and the upper surface 110 of the substrate 100, and may be any one of silicon, epoxy, conductive epoxy, conductive silicon, conductive adhesive, conductive film, and metal paste.

This bonding process may be performed in pixel array units. Therefore, the first pixel array 400-1 may be adhered to the substrate 100, and then the second pixel array 400-2 may be adhered to the substrate 100. Alternatively, at least two pixel arrays 400-1 and 400-2 may be attached to the substrate 200 at the same time.

In the method of manufacturing the display device according to the exemplary embodiment of the present invention illustrated in FIGS. 6A to 6I, the pixel array includes a plurality of light emitting parts 300 on the display panel substrate 100. Since each light emitting chip is formed in units, processes such as pick and place, transfer, and soldering are unnecessary for each light emitting chip. Therefore, there is an advantage that the manufacturing time of a display device having tens of thousands of pixels is greatly shortened. In addition, the first conductive semiconductor layer 301 is used as a common layer, and the materials and structures of the plurality of active layers 302a, 302b, and 302c and the plurality of second conductive semiconductor layers 303a, 303b, and 303c are different from each other. Since it is the same, it is possible to operate in the same conditions and environments, and there is an advantage that a reliable display device can be manufactured quickly.

The features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to the other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be interpreted that the contents related to such a combination and modification are included in the scope of the present invention.

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains should be provided within the scope not departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are not possible. For example, each component specifically shown in embodiment can be modified and implemented. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

10: growth substrate
200: metal layer
100: substrate
300: light emitting unit
310: light emitting cell
500: protective layer

Claims (19)

Board; And a plurality of light emitting parts arranged in an array form on the substrate.
Each of the plurality of light emitting parts may include a metal layer disposed on the substrate; A light emitting cell disposed on the metal layer and emitting light of different wavelengths; And a driving part disposed on the metal layer to electrically drive the light emitting cell.
The light emitting cell,
A first conductivity type semiconductor layer disposed on the metal layer as a common layer;
A plurality of active layers spaced apart from each other on one plane on the first conductive semiconductor layer and emitting light of a specific wavelength;
A second conductivity type semiconductor layer disposed on each of the plurality of active layers; And
It includes; a wavelength conversion layer disposed on the second conductivity type semiconductor layer,
Display device. The method of claim 1,
And at least two or more light emitting units of the plurality of light emitting units are configured to include the metal layer as a common layer. The method of claim 1,
And the substrate is any one of a glass substrate, a flexible film, a metal PCB, and a ceramic PCB. The method of claim 1,
And the plurality of active layers emit light of blue wavelength or light of ultraviolet wavelength. The method of claim 1,
The thickness of the metal layer is a display device, 10 ~ 100㎛. The method of claim 1,
The light emitting cell includes a first light emitting region emitting red light, a second light emitting region emitting green light, and a third light emitting region emitting blue light. The method of claim 6,
The size of the first light emitting area, the second light emitting area and the third light emitting area is 5 ~ 200㎛, display device. The method of claim 1,
The light emitting cell includes a first light emitting region emitting light of a first red wavelength, a second light emitting region emitting light of a second red wavelength, a third light emitting region emitting light of a green wavelength, and light of a blue wavelength. And a fourth light emitting area for emitting. The method of claim 1,
And the wavelength conversion layer is not disposed on the second conductivity type semiconductor layer in at least one of the plurality of light emitting regions. The method of claim 1,
And the wavelength conversion layer comprises a quantum dot phosphor or a YAG phosphor. Separating the light emitting structures formed on the growth substrate into a plurality of separate light emitting structures corresponding to the plurality of light emitting units, and separating each of the separated light emitting structures into a plurality of light emitting regions;
A driving unit forming step of forming driving units for each of the light emitting regions on one side of the separated light emitting structure as the growth substrate;
A peeling step of peeling the growth substrate from the light emitting structure and the driving part;
A metal layer forming step of forming a metal layer under the light emitting structure and the driving unit;
Forming a wavelength conversion layer on all or part of the plurality of light emitting regions;
Dicing the light emitting structure in a pixel array unit including at least two light emitting units of the plurality of light emitting units; And
A substrate bonding step of adhering the plurality of light emitting units to the display panel substrate in the pixel array unit;
A manufacturing method of a display device, including. The method of claim 11,
And the metal layer forming step and the dicing step are performed such that the at least two light emitting parts included in the pixel array include the metal layer as a common layer. The method of claim 11,
The peeling step, the method of manufacturing a display device to peel off the growth substrate using a laser lift off or chemical lift off method. The method of claim 11,
The light emitting structure includes a first conductive semiconductor layer, an active layer disposed on the first conductive semiconductor layer, and a second conductive semiconductor layer disposed on the active layer,
The separating step is performed by etching the second conductive semiconductor layer and the active layer to correspond to the number and arrangement of the plurality of light emitting regions. The method of claim 11,
In the forming of the wavelength conversion layer, the wavelength conversion layer may be formed on all or a part of the emission area by printing or dispensing a phosphor solution containing silicon and any one of a quantum dot phosphor and a YAG phosphor. The manufacturing method of a display apparatus to form. The method of claim 11,
The encapsulation step of encapsulating the light emitting structure, the wavelength conversion layer and the driving unit with a protective part. The method of claim 11,
And forming an electrode pattern electrically connecting the second conductive semiconductor layer in the light emitting area to a corresponding driving part of the light emitting area. Dicing a plurality of light emitting units arranged in an array form on the metal layer in a pixel array unit including at least two light emitting units; And
Adhering the diced pixel array onto a display substrate;
Each of the plurality of light emitting parts may include: a light emitting cell disposed on a metal layer and emitting light having a different wavelength; And a driving unit disposed on the metal layer to electrically drive the light emitting cell.
The light emitting cell,
A first conductivity type semiconductor layer disposed on the metal layer as a common layer;
A plurality of active layers spaced apart from each other on one plane on the first conductive semiconductor layer and emitting light having a specific wavelength;
A second conductivity type semiconductor layer disposed on each of the plurality of active layers; And
It includes; a wavelength conversion layer disposed on the second conductivity type semiconductor layer,
Method of manufacturing a display device. The method of claim 18,
And the dicing step is performed such that the at least two light emitting parts included in the pixel array include the metal layer as a common layer.

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