KR102442052B1 - Display device using semiconductor light emitting device - Google Patents

Abstract

A display device according to the present invention includes a substrate on which a wiring electrode is formed, a plurality of semiconductor light emitting devices electrically connected to the wiring electrode, and a red phosphor layer that absorbs light and converts it into red light, wherein the plurality of semiconductors include: The light emitting devices include blue semiconductor light emitting devices and green semiconductor light emitting devices, and the red phosphor layer overlaps any part of the green semiconductor light emitting devices so that red light and green light are output through the green semiconductor light emitting devices. characterized by being

Description

Display device using semiconductor light emitting device {DISPLAY DEVICE USING SEMICONDUCTOR LIGHT EMITTING DEVICE}

The present invention relates to a display device, and more particularly, to a flexible display device using a semiconductor light emitting device.

Recently, in the field of display technology, display devices having excellent characteristics, such as thin and flexible, have been developed. On the other hand, currently commercialized main displays are represented by LCD (Liguid Crystal Display) and AMOLED (Active Matrix Organic Light Emitting Diodes).

However, in the case of LCD, there are problems in that the response time is not fast and it is difficult to implement flexibility, and in the case of AMOLED, the lifespan is short, the mass production yield is not good, and there are weaknesses in that the degree of flexibility is weak.

Meanwhile, a light emitting diode (Light Emitting Diode: LED) is a well-known semiconductor light emitting device that converts electric current into light. It has been used as a light source for display images of electronic devices including communication devices. Accordingly, a method for solving the above problems by implementing a flexible display using the semiconductor light emitting device may be proposed.

A structure for exciting light emitted from the semiconductor light emitting device using a phosphor layer may be applied to a flexible display using the semiconductor light emitting device. More specifically, the phosphor layer absorbs the high energy light emitted from the blue semiconductor light emitting device and emits light of a different wavelength. Since the light emitted from the blue semiconductor light emitting device has high energy, in order for the phosphor layer to have a high light absorption rate, the concentration of the phosphor contained in the phosphor layer must be at least a certain level or the thickness of the phosphor layer itself must be at least a certain level. do. However, there is a limit to increasing the concentration of the phosphor included in the phosphor layer above a certain level, and when the thickness of the phosphor layer is increased, there is a problem in that the thickness of the display device is increased.

SUMMARY OF THE INVENTION One object of the present invention is to provide a display device having improved color conversion reliability of phosphors.

Another object of the present invention is to provide a display device capable of reducing the thickness of the color conversion layer.

Another object of the present invention is to provide a display device capable of uniformly distributing light in pixels.

A display device according to the present invention includes a substrate on which a wiring electrode is formed, a plurality of semiconductor light emitting devices electrically connected to the wiring electrode, and a red phosphor layer that absorbs light and converts it into red light, wherein the plurality of semiconductors include: The light emitting devices include blue semiconductor light emitting devices and green semiconductor light emitting devices, and the red phosphor layer overlaps any part of the green semiconductor light emitting devices so that red light and green light are output through the green semiconductor light emitting devices. characterized by being

In an embodiment, the display device further includes a green phosphor layer that absorbs light and converts it into green light, and overlaps with some other of the green semiconductor light emitting devices, wherein the green light converted from the green phosphor layer and the green light converted by the green phosphor layer Wavelengths of green light emitted from the green semiconductor light emitting device may be different from each other.

In an embodiment, a wavelength of green light converted by the green phosphor layer may be longer than a wavelength of green light emitted from the green semiconductor light emitting device.

In an embodiment, the light absorptivity of the phosphor layers with respect to green light may be higher than that of the blue light of the phosphor layers.

In an embodiment, the plurality of semiconductor light emitting devices may form a plurality of pixels, and each of the plurality of pixels may include a first area in which the semiconductor light emitting device is disposed and a second area other than the first area. have.

In an embodiment, the light emitting diode may further include a scattering layer overlapping the at least a portion so that light emitted from at least some of the semiconductor light emitting devices is emitted from the second region to the outside.

In an embodiment, the scattering layers may be disposed to cover the green semiconductor light emitting device.

In an embodiment, the scattering layers may be disposed between the at least part and the phosphor layer covering the at least part.

In an embodiment, the scattering layer may be made of a porous material or TiO2.

In an embodiment, the phosphor layer may be formed of an organic phosphor.

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In the display device according to the present invention, since color conversion is performed using green light having a high light absorptivity in the phosphor layer, the phosphor layer having a low phosphor concentration can have a light absorptivity of at least a certain level, and the thickness of the phosphor layer can be reduced Accordingly, the thickness of the display device may be reduced.

In addition, in the present invention, a scattering layer disposed between the semiconductor light emitting device and the phosphor layer scatters light emitted from the semiconductor light emitting device, so that the semiconductor light emitting device is not disposed to be emitted to the outside. Accordingly, light can be uniformly emitted in the entire area of each pixel.

1 is a conceptual diagram illustrating an embodiment of a display device using a semiconductor light emitting device of the present invention.
FIG. 2 is a partially enlarged view of part A of FIG. 1 , and FIGS. 3A and 3B are cross-sectional views taken along lines BB and CC of FIG. 2 .
4 is a conceptual diagram illustrating the flip-chip type semiconductor light emitting device of FIG. 3 .
5A to 5C are conceptual views illustrating various forms of implementing colors in relation to a flip-chip type semiconductor light emitting device.
6 is a cross-sectional view illustrating a method of manufacturing a display device using a semiconductor light emitting device of the present invention.
7 is a perspective view illustrating another embodiment of a display device using the semiconductor light emitting device of the present invention.
FIG. 8 is a cross-sectional view taken along line DD of FIG. 7 ;
9 is a conceptual diagram illustrating the vertical semiconductor light emitting device of FIG. 8 .
10 is an enlarged view of part A of FIG. 1 for explaining another embodiment of the present invention to which a semiconductor light emitting device of a new structure is applied.
11A is a cross-sectional view taken along line EE of FIG. 10 .
11B is a cross-sectional view taken along line FF of FIG. 10 .
12 is a conceptual diagram illustrating the flip chip type semiconductor light emitting device of FIG. 11A .
13 and 14 are cross-sectional views taken along line FF of FIG. 10 for describing still another embodiment of the present invention.
15 and 16 are conceptual diagrams illustrating the structure of individual pixels constituting a display device.
17a and 17b are cross-sectional views taken along line FF of FIG. 10 for describing still another embodiment of the present invention.
18A to 18C and 19A to 19D are cross-sectional views illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves. In addition, in describing the embodiments disclosed in the present 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 description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical spirit disclosed in the present specification by the accompanying drawings.

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

The display device described in this specification includes a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, and a slate PC. , Tablet PC, Ultra Book, digital TV, desktop computer, and the like. However, it will be readily apparent to those skilled in the art that the configuration according to the embodiment described herein may be applied to a display capable device even in a new product form to be developed later.

1 is a conceptual diagram illustrating an embodiment of a display device using a semiconductor light emitting device of the present invention.

As illustrated, information processed by the control unit of the display apparatus 100 may be displayed using a flexible display.

The flexible display includes a display that can be bent, bent, twisted, folded, or rolled by an external force. For example, the flexible display may be a display manufactured on a thin and flexible substrate that can be bent, bent, folded, or rolled like paper while maintaining the display characteristics of a conventional flat panel display.

In a state in which the flexible display is not bent (eg, a state having an infinite radius of curvature, hereinafter referred to as a first state), the display area of the flexible display becomes a flat surface. In a state bent by an external force in the first state (for example, a state having a finite radius of curvature, hereinafter referred to as a second state), the display area may be a curved surface. As illustrated, the information displayed in the second state may be visual information output on the curved surface. Such visual information is implemented by independently controlling the light emission of sub-pixels arranged in a matrix form. The unit pixel means a minimum unit for realizing one color.

The unit pixel of the flexible display may be implemented by a semiconductor light emitting device. In the present invention, a light emitting diode (LED) is exemplified as a type of a semiconductor light emitting device that converts current into light. The light emitting diode is formed in a small size, so that it can serve as a unit pixel even in the second state.

Hereinafter, a flexible display implemented using the light emitting diode will be described in more detail with reference to the drawings.

2 is a partially enlarged view of part A of FIG. 1, FIGS. 3A and 3B are cross-sectional views taken along lines B-B and C-C of FIG. 2, and FIG. 4 is a conceptual diagram illustrating the flip-chip type semiconductor light emitting device of FIG. 3A, 5A to 5C are conceptual views illustrating various forms of implementing colors in relation to a flip-chip type semiconductor light emitting device.

Referring to FIGS. 2, 3A and 3B , the display device 100 using a passive matrix (PM) type semiconductor light emitting device is exemplified as the display device 100 using a semiconductor light emitting device. However, the examples described below are also applicable to an active matrix (AM) type semiconductor light emitting device.

The display device 100 includes a substrate 110 , a first electrode 120 , a conductive adhesive layer 130 , a second electrode 140 , and a plurality of semiconductor light emitting devices 150 .

The substrate 110 may be a flexible substrate. For example, in order to implement a flexible display device, the substrate 110 may include glass or polyimide (PI). In addition, any material such as polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) may be used as long as it has insulating properties and is flexible. In addition, the substrate 110 may be made of either a transparent material or an opaque material.

The substrate 110 may be a wiring substrate on which the first electrode 120 is disposed, and thus the first electrode 120 may be located on the substrate 110 .

As shown, the insulating layer 160 may be disposed on the substrate 110 on which the first electrode 120 is positioned, and the auxiliary electrode 170 may be positioned on the insulating layer 160 . In this case, a state in which the insulating layer 160 is laminated on the substrate 110 may be a single wiring board. More specifically, the insulating layer 160 is made of an insulating and flexible material such as polyimide (PI, Polyimide), PET, or PEN, and may be integrally formed with the substrate 110 to form a single substrate.

The auxiliary electrode 170 is an electrode that electrically connects the first electrode 120 and the semiconductor light emitting device 150 , is located on the insulating layer 160 , and is disposed to correspond to the position of the first electrode 120 . For example, the auxiliary electrode 170 may have a dot shape and may be electrically connected to the first electrode 120 by an electrode hole 171 penetrating the insulating layer 160 . The electrode hole 171 may be formed by filling the via hole with a conductive material.

Referring to the drawings, the conductive adhesive layer 130 is formed on one surface of the insulating layer 160 , but the present invention is not necessarily limited thereto. For example, a layer performing a specific function is formed between the insulating layer 160 and the conductive adhesive layer 130 , or the conductive adhesive layer 130 is disposed on the substrate 110 without the insulating layer 160 . is also possible In a structure in which the conductive adhesive layer 130 is disposed on the substrate 110 , the conductive adhesive layer 130 may serve as an insulating layer.

The conductive adhesive layer 130 may be a layer having adhesiveness and conductivity, and for this purpose, a material having conductivity and a material having adhesiveness may be mixed in the conductive adhesive layer 130 . In addition, the conductive adhesive layer 130 has ductility, thereby enabling a flexible function in the display device.

For this example, the conductive adhesive layer 130 may be an anisotropic conductive film (ACF), an anisotropic conductive paste, a solution containing conductive particles, or the like. The conductive adhesive layer 130 may be configured as a layer that allows electrical interconnection in the Z direction passing through the thickness, but has electrical insulation in the horizontal X-Y direction. Accordingly, the conductive adhesive layer 130 may be referred to as a Z-axis conductive layer (hereinafter, referred to as a 'conductive adhesive layer').

The anisotropic conductive film is a film in which an anisotropic conductive medium is mixed with an insulating base member, and when heat and pressure are applied, only a specific portion has conductivity by the anisotropic conductive medium. Hereinafter, it will be described that heat and pressure are applied to the anisotropic conductive film, but other methods are also possible in order for the anisotropic conductive film to have partial conductivity. In this method, for example, only one of the heat and pressure may be applied or UV curing may be performed.

In addition, the anisotropic conductive medium may be, for example, conductive balls or conductive particles. As shown, in this example, the anisotropic conductive film is a film in which conductive balls are mixed with an insulating base member, and when heat and pressure are applied, only a specific portion has conductivity by the conductive balls. The anisotropic conductive film may be in a state in which the core of the conductive material contains a plurality of particles covered by an insulating film made of a polymer material. . At this time, the shape of the core may be deformed to form a layer in contact with each other in the thickness direction of the film. As a more specific example, heat and pressure are applied as a whole to the anisotropic conductive film, and electrical connection in the Z-axis direction is partially formed due to a height difference of an object adhered by the anisotropic conductive film.

As another example, the anisotropic conductive film may be in a state in which an insulating core contains a plurality of particles coated with a conductive material. In this case, the conductive material is deformed (pressed) in the portion to which heat and pressure are applied, so that it has conductivity in the thickness direction of the film. As another example, a form in which the conductive material penetrates the insulating base member in the Z-axis direction to have conductivity in the thickness direction of the film is also possible. In this case, the conductive material may have a pointed end.

As shown, the anisotropic conductive film may be a fixed array anisotropic conductive film (ACF) in which conductive balls are inserted into one surface of the insulating base member. More specifically, the insulating base member is formed of a material having an adhesive property, and the conductive balls are intensively disposed on the bottom of the insulating base member, and when heat and pressure are applied from the base member, it is deformed together with the conductive balls. It has conductivity in the vertical direction.

However, the present invention is not necessarily limited thereto, and the anisotropic conductive film has a form in which conductive balls are randomly mixed in an insulating base member, or is composed of a plurality of layers and conductive balls are arranged on one layer (double- ACF) are all possible.

The anisotropic conductive paste is a combination of a paste and a conductive ball, and may be a paste in which a conductive ball is mixed with an insulating and adhesive base material. Also, a solution containing conductive particles may be a solution containing conductive particles or nano particles.

Referring back to the drawing, the second electrode 140 is spaced apart from the auxiliary electrode 170 and is positioned on the insulating layer 160 . That is, the conductive adhesive layer 130 is disposed on the insulating layer 160 in which the auxiliary electrode 170 and the second electrode 140 are located.

After the conductive adhesive layer 130 is formed in a state in which the auxiliary electrode 170 and the second electrode 140 are positioned on the insulating layer 160 , the semiconductor light emitting device 150 is connected in a flip-chip form by applying heat and pressure. In this case, the semiconductor light emitting device 150 is electrically connected to the first electrode 120 and the second electrode 140 .

Referring to FIG. 4 , the semiconductor light emitting device may be a flip chip type light emitting device.

For example, the semiconductor light emitting device includes a p-type electrode 156 , a p-type semiconductor layer 155 on which the p-type electrode 156 is formed, an active layer 154 formed on the p-type semiconductor layer 155 , an active layer ( It includes an n-type semiconductor layer 153 formed on the 154 , and an n-type electrode 152 spaced apart from the p-type electrode 156 in the horizontal direction on the n-type semiconductor layer 153 . In this case, the p-type electrode 156 may be electrically connected to the auxiliary electrode 170 and the conductive adhesive layer 130 , and the n-type electrode 152 may be electrically connected to the second electrode 140 .

Referring back to FIGS. 2 , 3A and 3B , the auxiliary electrode 170 is formed to be elongated in one direction, so that one auxiliary electrode can be electrically connected to the plurality of semiconductor light emitting devices 150 . For example, p-type electrodes of left and right semiconductor light emitting devices with respect to the auxiliary electrode may be electrically connected to one auxiliary electrode.

More specifically, the semiconductor light emitting device 150 is press-fitted into the conductive adhesive layer 130 by heat and pressure, and through this, between the p-type electrode 156 and the auxiliary electrode 170 of the semiconductor light emitting device 150 . Only a portion and a portion between the n-type electrode 152 and the second electrode 140 of the semiconductor light emitting device 150 have conductivity, and there is no press-fitting of the semiconductor light emitting device in the remaining portion, so that the semiconductor light emitting device does not have conductivity. As described above, the conductive adhesive layer 130 not only interconnects the semiconductor light emitting device 150 and the auxiliary electrode 170 and between the semiconductor light emitting device 150 and the second electrode 140 , but also forms an electrical connection.

In addition, the plurality of semiconductor light emitting devices 150 constitute a light emitting device array, and the phosphor layer 180 is formed on the light emitting device array.

The light emitting device array may include a plurality of semiconductor light emitting devices having different luminance values. Each semiconductor light emitting device 150 constitutes a unit pixel and is electrically connected to the first electrode 120 . For example, there may be a plurality of first electrodes 120 , the semiconductor light emitting devices may be arranged in, for example, several columns, and the semiconductor light emitting devices in each column may be electrically connected to any one of the plurality of first electrodes.

In addition, since the semiconductor light emitting devices are connected in a flip-chip form, semiconductor light emitting devices grown on a transparent dielectric substrate can be used. In addition, the semiconductor light emitting devices may be, for example, nitride semiconductor light emitting devices. Since the semiconductor light emitting device 150 has excellent luminance, individual unit pixels can be configured even with a small size.

As illustrated, a barrier rib 190 may be formed between the semiconductor light emitting devices 150 . In this case, the partition wall 190 may serve to separate individual unit pixels from each other, and may be integrally formed with the conductive adhesive layer 130 . For example, by inserting the semiconductor light emitting device 150 into the anisotropic conductive film, the base member of the anisotropic conductive film may form the partition wall.

In addition, when the base member of the anisotropic conductive film is black, the barrier rib 190 may have reflective properties and increase contrast even without a separate black insulator.

As another example, a reflective barrier rib may be separately provided as the barrier rib 190 . In this case, the barrier rib 190 may include a black or white insulator depending on the purpose of the display device. When the barrier ribs made of a white insulator are used, reflectivity may be increased, and when the barrier ribs made of a black insulator are used, it is possible to have reflective properties and increase contrast.

The phosphor layer 180 may be located on the outer surface of the semiconductor light emitting device 150 . For example, the semiconductor light emitting device 150 is a blue semiconductor light emitting device that emits blue (B) light, and the phosphor layer 180 performs a function of converting the blue (B) light into a color of a unit pixel. The phosphor layer 180 may be a red phosphor 181 or a green phosphor 182 constituting an individual pixel.

That is, a red phosphor 181 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 151 at a position forming a unit pixel of red color, and a position constituting a unit pixel of green color In , a green phosphor 182 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 151 . In addition, only the blue semiconductor light emitting device 151 may be used alone in the portion constituting the blue unit pixel. In this case, unit pixels of red (R), green (G), and blue (B) may form one pixel. More specifically, a phosphor of one color may be stacked along each line of the first electrode 120 . Accordingly, one line in the first electrode 120 may be an electrode for controlling one color. That is, red (R), green (G), and blue (B) may be sequentially disposed along the second electrode 140 , thereby realizing a unit pixel.

However, the present invention is not necessarily limited thereto, and instead of the phosphor, the semiconductor light emitting device 150 and the quantum dot (QD) are combined to implement unit pixels of red (R), green (G), and blue (B). have.

In addition, a black matrix 191 may be disposed between each of the phosphor layers to improve contrast. That is, the black matrix 191 may improve contrast of light and dark.

However, the present invention is not necessarily limited thereto, and other structures for implementing blue, red, and green colors may be applied.

Referring to FIG. 5A , each semiconductor light emitting device 150 mainly uses gallium nitride (GaN), and indium (In) and/or aluminum (Al) are added together to emit a variety of light including blue light. It can be implemented as a device.

In this case, the semiconductor light emitting device 150 may be a red, green, and blue semiconductor light emitting device to form a sub-pixel, respectively. For example, red, green, and blue semiconductor light emitting devices R, G, and B are alternately disposed, and unit pixels of red, green, and blue are formed by the red, green and blue semiconductor light emitting devices. The pixels form one pixel, through which a full-color display can be realized.

Referring to FIG. 5B , the semiconductor light emitting device may include a white light emitting device W in which a yellow phosphor layer is provided for each device. In this case, a red phosphor layer 181 , a green phosphor layer 182 , and a blue phosphor layer 183 may be provided on the white light emitting device W to form a unit pixel. In addition, a unit pixel may be formed on the white light emitting device W by using a color filter in which red, green, and blue are repeated.

Referring to FIG. 5C , a structure in which a red phosphor layer 181 , a green phosphor layer 182 , and a blue phosphor layer 183 are provided on the ultraviolet light emitting device UV is also possible. In this way, the semiconductor light emitting device can be used in the entire range of visible light as well as ultraviolet (UV) light, and can be extended to the form of a semiconductor light emitting device in which ultraviolet (UV) can be used as an excitation source of the upper phosphor. .

Referring back to this example, the semiconductor light emitting device 150 is positioned on the conductive adhesive layer 130 to constitute a unit pixel in the display device. Since the semiconductor light emitting device 150 has excellent luminance, individual unit pixels can be configured even with a small size. The size of the individual semiconductor light emitting device 150 may have a side length of 80 μm or less, and may be a rectangular or square device. In the case of a rectangular shape, the size may be 20X80㎛ or less.

In addition, even when a square semiconductor light emitting device 150 having a side length of 10 μm is used as a unit pixel, sufficient brightness to form a display device appears. Accordingly, for example, when the unit pixel is a rectangular pixel having one side of 600 μm and the other side of 300 μm, the distance between the semiconductor light emitting devices is relatively large. Accordingly, in this case, it is possible to implement a flexible display device having HD image quality.

The display device using the semiconductor light emitting device described above can be manufactured by a new type of manufacturing method. Hereinafter, the manufacturing method will be described with reference to FIG. 6 .

6 is a cross-sectional view illustrating a method of manufacturing a display device using a semiconductor light emitting device of the present invention.

Referring to this figure, first, a conductive adhesive layer 130 is formed on the insulating layer 160 on which the auxiliary electrode 170 and the second electrode 140 are positioned. An insulating layer 160 is laminated on the first substrate 110 to form one substrate (or wiring board), and the wiring substrate includes a first electrode 120 , an auxiliary electrode 170 , and a second electrode 140 . this is placed In this case, the first electrode 120 and the second electrode 140 may be disposed in a mutually orthogonal direction. In addition, in order to implement a flexible display device, the first substrate 110 and the insulating layer 160 may each include glass or polyimide (PI).

The conductive adhesive layer 130 may be implemented by, for example, an anisotropic conductive film, and for this purpose, the anisotropic conductive film may be applied to the substrate on which the insulating layer 160 is located.

Next, the second substrate 112 corresponding to the positions of the auxiliary electrode 170 and the second electrodes 140 and on which the plurality of semiconductor light emitting devices 150 constituting individual pixels are located is formed with the semiconductor light emitting device 150 . ) is disposed to face the auxiliary electrode 170 and the second electrode 140 .

In this case, the second substrate 112 is a growth substrate on which the semiconductor light emitting device 150 is grown, and may be a sapphire substrate or a silicon substrate.

When the semiconductor light emitting device is formed in a wafer unit, the semiconductor light emitting device can be effectively used in a display device by having an interval and a size that can form a display device.

Then, the wiring board and the second board 112 are thermocompression-bonded. For example, the wiring substrate and the second substrate 112 may be thermocompression-bonded by applying an ACF press head. The wiring substrate and the second substrate 112 are bonded by the thermocompression bonding. Due to the properties of the anisotropic conductive film having conductivity by thermocompression bonding, only a portion between the semiconductor light emitting device 150 and the auxiliary electrode 170 and the second electrode 140 has conductivity, and through this, the electrodes and the semiconductor light emission. The device 150 may be electrically connected. At this time, the semiconductor light emitting device 150 is inserted into the anisotropic conductive film, through which a barrier rib may be formed between the semiconductor light emitting devices 150 .

Then, the second substrate 112 is removed. For example, the second substrate 112 may be removed using a laser lift-off (LLO) method or a chemical lift-off (CLO) method.

Finally, the second substrate 112 is removed to expose the semiconductor light emitting devices 150 to the outside. If necessary, a transparent insulating layer (not shown) may be formed by coating silicon oxide (SiOx) or the like on the wiring board to which the semiconductor light emitting device 150 is coupled.

In addition, the method may further include forming a phosphor layer on one surface of the semiconductor light emitting device 150 . For example, the semiconductor light emitting device 150 is a blue semiconductor light emitting device that emits blue (B) light, and a red or green phosphor for converting the blue (B) light into the color of a unit pixel is the blue semiconductor light emitting device. A layer may be formed on one surface of the device.

The manufacturing method or structure of the display device using the semiconductor light emitting device described above may be modified in various forms. As an example, a vertical semiconductor light emitting device may also be applied to the display device described above. Hereinafter, a vertical structure will be described with reference to FIGS. 5 and 6 .

In addition, in the modification or embodiment described below, the same or similar reference numerals are assigned to the same or similar components as those of the preceding example, and the description is replaced with the first description.

7 is a perspective view showing another embodiment of a display device using the semiconductor light emitting device of the present invention, FIG. 8 is a cross-sectional view taken along line D-D of FIG. 7 , and FIG. 9 is a conceptual view showing the vertical semiconductor light emitting device of FIG. 8 to be.

Referring to the drawings, the display device may be a display device using a passive matrix (PM) type vertical semiconductor light emitting device.

The display device includes a substrate 210 , a first electrode 220 , a conductive adhesive layer 230 , a second electrode 240 , and a plurality of semiconductor light emitting devices 250 .

The substrate 210 is a wiring substrate on which the first electrode 220 is disposed, and may include polyimide (PI) to implement a flexible display device. In addition, any material that has insulating properties and is flexible may be used.

The first electrode 220 is positioned on the substrate 210 and may be formed as a bar-shaped electrode long in one direction. The first electrode 220 may serve as a data electrode.

The conductive adhesive layer 230 is formed on the substrate 210 on which the first electrode 220 is positioned. Like a display device to which a flip chip type light emitting device is applied, the conductive adhesive layer 230 may include an anisotropic conductive film (ACF), an anisotropic conductive paste, and a solution containing conductive particles. ), and so on. However, in this embodiment as well, a case in which the conductive adhesive layer 230 is implemented by an anisotropic conductive film is exemplified.

After the anisotropic conductive film is positioned on the substrate 210 in a state where the first electrode 220 is positioned, when the semiconductor light emitting device 250 is connected by applying heat and pressure, the semiconductor light emitting device 250 becomes the first It is electrically connected to the electrode 220 . In this case, the semiconductor light emitting device 250 is preferably disposed on the first electrode 220 .

The electrical connection is created because, as described above, the anisotropic conductive film partially has conductivity in the thickness direction when heat and pressure are applied thereto. Accordingly, the anisotropic conductive film is divided into a conductive portion and a non-conductive portion in the thickness direction.

In addition, since the anisotropic conductive film contains an adhesive component, the conductive adhesive layer 230 implements not only electrical connection but also mechanical bonding between the semiconductor light emitting device 250 and the first electrode 220 .

As described above, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230 and constitutes individual pixels in the display device through this. Since the semiconductor light emitting device 250 has excellent luminance, individual unit pixels can be configured even with a small size. The size of such an individual semiconductor light emitting device 250 may have a side length of 80 μm or less, and may be a rectangular or square device. In the case of a rectangular shape, the size may be 20X80㎛ or less.

The semiconductor light emitting device 250 may have a vertical structure.

A plurality of second electrodes 240 disposed in a direction crossing the longitudinal direction of the first electrode 220 and electrically connected to the vertical semiconductor light emitting device 250 are positioned between the vertical semiconductor light emitting devices.

Referring to FIG. 9 , the vertical semiconductor light emitting device includes a p-type electrode 256 , a p-type semiconductor layer 255 formed on the p-type electrode 256 , and an active layer 254 formed on the p-type semiconductor layer 255 . ), an n-type semiconductor layer 253 formed on the active layer 254 , and an n-type electrode 252 formed on the n-type semiconductor layer 253 . In this case, the lower p-type electrode 256 may be electrically connected to the first electrode 220 and the conductive adhesive layer 230 , and the upper n-type electrode 252 may be a second electrode 240 to be described later. ) can be electrically connected to. The vertical semiconductor light emitting device 250 has a great advantage in that it can reduce the chip size because electrodes can be arranged up and down.

Referring back to FIG. 8 , a phosphor layer 280 may be formed on one surface of the semiconductor light emitting device 250 . For example, the semiconductor light emitting device 250 is a blue semiconductor light emitting device 251 that emits blue (B) light, and a phosphor layer 280 for converting the blue (B) light into the color of a unit pixel is provided. can be In this case, the phosphor layer 280 may be a red phosphor 281 and a green phosphor 282 constituting individual pixels.

That is, a red phosphor 281 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 251 at a position constituting a unit pixel of red color, and a position constituting a unit pixel of green color In , a green phosphor 282 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 251 . In addition, only the blue semiconductor light emitting device 251 may be used alone in the portion constituting the blue unit pixel. In this case, unit pixels of red (R), green (G), and blue (B) may form one pixel.

However, the present invention is not necessarily limited thereto, and as described above in a display device to which a flip chip type light emitting device is applied, other structures for implementing blue, red, and green colors may be applied.

Referring back to this embodiment, the second electrode 240 is positioned between the semiconductor light emitting devices 250 and is electrically connected to the semiconductor light emitting devices 250 . For example, the semiconductor light emitting devices 250 may be arranged in a plurality of columns, and the second electrode 240 may be located between the columns of the semiconductor light emitting devices 250 .

Since the distance between the semiconductor light emitting devices 250 constituting individual pixels is sufficiently large, the second electrode 240 may be positioned between the semiconductor light emitting devices 250 .

The second electrode 240 may be formed as a bar-shaped electrode long in one direction, and may be disposed in a direction perpendicular to the first electrode.

Also, the second electrode 240 and the semiconductor light emitting device 250 may be electrically connected to each other by a connection electrode protruding from the second electrode 240 . More specifically, the connection electrode may be an n-type electrode of the semiconductor light emitting device 250 . For example, the n-type electrode is formed as an ohmic electrode for ohmic contact, and the second electrode covers at least a portion of the ohmic electrode by printing or deposition. Through this, the second electrode 240 and the n-type electrode of the semiconductor light emitting device 250 may be electrically connected.

As illustrated, the second electrode 240 may be positioned on the conductive adhesive layer 230 . In some cases, a transparent insulating layer (not shown) including silicon oxide (SiOx) may be formed on the substrate 210 on which the semiconductor light emitting device 250 is formed. When the second electrode 240 is positioned after the transparent insulating layer is formed, the second electrode 240 is positioned on the transparent insulating layer. In addition, the second electrode 240 may be formed to be spaced apart from the conductive adhesive layer 230 or the transparent insulating layer.

If a transparent electrode such as indium tin oxide (ITO) is used to position the second electrode 240 on the semiconductor light emitting device 250 , the ITO material has a problem of poor adhesion to the n-type semiconductor layer. have. Accordingly, the present invention has the advantage of not using a transparent electrode such as ITO by locating the second electrode 240 between the semiconductor light emitting devices 250 . Therefore, it is possible to improve light extraction efficiency by using a conductive material having good adhesion to the n-type semiconductor layer as a horizontal electrode without being limited by the selection of a transparent material.

As illustrated, a barrier rib 290 may be positioned between the semiconductor light emitting devices 250 . That is, a barrier rib 290 may be disposed between the vertical semiconductor light emitting devices 250 to isolate the semiconductor light emitting devices 250 constituting individual pixels. In this case, the partition wall 290 may serve to separate individual unit pixels from each other, and may be integrally formed with the conductive adhesive layer 230 . For example, by inserting the semiconductor light emitting device 250 into the anisotropic conductive film, the base member of the anisotropic conductive film may form the partition wall.

In addition, when the base member of the anisotropic conductive film is black, the barrier rib 290 may have reflective properties and increase contrast even without a separate black insulator.

As another example, as the barrier rib 190 , a reflective barrier rib may be separately provided. The barrier rib 290 may include a black or white insulator depending on the purpose of the display device.

If the second electrode 240 is directly positioned on the conductive adhesive layer 230 between the semiconductor light emitting devices 250 , the barrier rib 290 is formed between the vertical semiconductor light emitting device 250 and the second electrode 240 . can be located between Accordingly, individual unit pixels can be configured even with a small size using the semiconductor light emitting device 250 , and the distance between the semiconductor light emitting devices 250 is relatively large enough to connect the second electrode 240 to the semiconductor light emitting device 250 . ), and there is an effect of realizing a flexible display device having HD image quality.

Also, as illustrated, a black matrix 291 may be disposed between each phosphor in order to improve a contrast ratio. That is, the black matrix 291 may improve contrast of light and dark.

As described above, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230 and constitutes individual pixels in the display device through this. Since the semiconductor light emitting device 250 has excellent luminance, individual unit pixels can be configured even with a small size. Accordingly, a full-color display in which unit pixels of red (R), green (G), and blue (B) constitute one pixel may be implemented by the semiconductor light emitting device.

When the flip chip type is applied to the display device using the semiconductor light emitting device of the present invention described above, since the first and second electrodes are disposed on the same plane, it is difficult to implement high definition (fine pitch). Hereinafter, a display device to which a flip-chip type light emitting device is applied according to another embodiment of the present invention capable of solving such a problem will be described.

10 is an enlarged view of part A of FIG. 1 for explaining another embodiment of the present invention to which a semiconductor light emitting device of a new structure is applied, FIG. 11A is a cross-sectional view taken along line E-E of FIG. 10, and FIG. 11B is FIG. 11 is a cross-sectional view taken along line F-F, and FIG. 12 is a conceptual diagram illustrating the flip-chip type semiconductor light emitting device of FIG. 11A.

10, 11A, and 11B , the display device 1000 using a passive matrix (PM) type semiconductor light emitting device is exemplified as the display device 1000 using a semiconductor light emitting device. However, the examples described below are also applicable to an active matrix (AM) type semiconductor light emitting device.

The display apparatus 1000 includes a substrate 1010 , a first electrode 1020 , a conductive adhesive layer 1030 , a second electrode 1040 , and a plurality of semiconductor light emitting devices 1050 . Here, the first electrode 1020 and the second electrode 1040 may each include a plurality of electrode lines.

The substrate 1010 is a wiring substrate on which the first electrode 1020 is disposed, and may include polyimide (PI) to implement a flexible display device. In addition, any material that has insulating properties and is flexible may be used.

The first electrode 1020 is positioned on the substrate 1010 and may be formed as a bar-shaped electrode long in one direction. The first electrode 1020 may serve as a data electrode.

The conductive adhesive layer 1030 is formed on the substrate 1010 on which the first electrode 1020 is positioned. Like the display device to which the above-described flip chip type light emitting element is applied, the conductive adhesive layer 1030 is an anisotropic conductive film (ACF), an anisotropic conductive paste, and a solution containing conductive particles. (solution), etc. However, in this embodiment, the conductive adhesive layer 1030 may be replaced with an adhesive layer. For example, if the first electrode 1020 is not positioned on the substrate 1010 and is integrally formed with the conductive electrode of the semiconductor light emitting device, the adhesive layer may not need to be conductive.

A plurality of second electrodes 1040 disposed in a direction crossing the longitudinal direction of the first electrode 1020 and electrically connected to the semiconductor light emitting device 1050 are positioned between the semiconductor light emitting devices.

As illustrated, the second electrode 1040 may be positioned on the conductive adhesive layer 1030 . That is, the conductive adhesive layer 1030 is disposed between the wiring board and the second electrode 1040 . The second electrode 1040 may be electrically connected to the semiconductor light emitting device 1050 by contact.

With the structure described above, the plurality of semiconductor light emitting devices 1050 are coupled to the conductive adhesive layer 1030 and electrically connected to the first electrode 1020 and the second electrode 1040 .

In some cases, a transparent insulating layer (not shown) including silicon oxide (SiOx) may be formed on the substrate 1010 on which the semiconductor light emitting device 1050 is formed. When the second electrode 1040 is positioned after the transparent insulating layer is formed, the second electrode 1040 is positioned on the transparent insulating layer. In addition, the second electrode 1040 may be formed to be spaced apart from the conductive adhesive layer 1030 or the transparent insulating layer.

As shown, the plurality of semiconductor light emitting devices 1050 may form a plurality of columns in a direction parallel to a plurality of electrode lines provided in the first electrode 1020 . However, the present invention is not necessarily limited thereto. For example, the plurality of semiconductor light emitting devices 1050 may form a plurality of columns along the second electrode 1040 .

Furthermore, the display apparatus 1000 may further include a phosphor layer 1080 formed on one surface of the plurality of semiconductor light emitting devices 1050 . For example, the semiconductor light emitting device 1050 is a blue semiconductor light emitting device that emits blue (B) light, and the phosphor layer 1080 converts the blue (B) light into a color of a unit pixel. The phosphor layer 1080 may be a red phosphor 1081 or a green phosphor 1082 constituting individual pixels. That is, a red phosphor 1081 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 1051a at a position constituting a unit pixel of red color, and a position constituting a unit pixel of green color In , a green phosphor 1082 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 1051b. In addition, only the blue semiconductor light emitting device 1051c may be used alone in the portion constituting the blue unit pixel. In this case, unit pixels of red (R), green (G), and blue (B) may form one pixel. More specifically, a phosphor of one color may be stacked along each line of the first electrode 1020 . Accordingly, one line in the first electrode 1020 may be an electrode for controlling one color. That is, red (R), green (G), and blue (B) may be sequentially disposed along the second electrode 1040 , thereby realizing a unit pixel. However, the present invention is not necessarily limited thereto, and instead of a phosphor, a unit pixel emitting red (R), green (G), and blue (B) is formed by combining the semiconductor light emitting device 1050 and quantum dots (QD). can be implemented

Meanwhile, in order to improve the contrast ratio of the phosphor layer 1080, the display device may further include a black matrix 1091 disposed between the respective phosphors. The black matrix 1091 may be formed in such a way that a gap is formed between the phosphor dots, and a black material fills the gap. Through this, the black matrix 1091 may absorb external light reflection and improve contrast of light and dark. The black matrix 1091 is positioned between the respective phosphor layers along the first electrode 1020 in the direction in which the phosphor layers 1080 are stacked. In this case, a phosphor layer is not formed at a position corresponding to the blue semiconductor light emitting device 1051 , but the black matrix 1091 is formed with a space without the phosphor layer therebetween (or the blue semiconductor light emitting device 1051c is interposed therebetween). to) can be formed on both sides.

Again, looking at the semiconductor light emitting device 1050 of this example, the semiconductor light emitting device 1050 in this example has a great advantage of reducing the chip size because electrodes can be arranged up and down. However, although the electrodes are arranged vertically, the semiconductor light emitting device of the present invention may be a flip chip type light emitting device.

Referring to FIG. 12 , for example, the semiconductor light emitting device 1050 includes a first conductive electrode 1156 and a first conductive semiconductor layer 1155 on which the first conductive electrode 1156 is formed; The active layer 1154 formed on the first conductivity type semiconductor layer 1155, the second conductivity type semiconductor layer 1153 formed on the active layer 1154, and the second conductivity type semiconductor layer 1153 formed on the second conductivity type semiconductor layer 1153 A conductive electrode 1152 is included.

More specifically, the first conductivity type electrode 1156 and the first conductivity type semiconductor layer 1155 may be a p-type electrode and a p-type semiconductor layer, respectively, and the second conductivity type electrode 1152 and the second conductivity type electrode 1152 , respectively. The conductive semiconductor layer 1153 may be an n-type electrode and an n-type semiconductor layer, respectively. However, the present invention is not necessarily limited thereto, and examples in which the first conductivity type is n-type and the second conductivity type is p-type are also possible.

More specifically, the first conductivity type electrode 1156 is formed on one surface of the first conductivity type semiconductor layer 1155 , and the active layer 1154 is formed on the other surface of the first conductivity type semiconductor layer 1155 and the It is formed between one surface of the second conductivity type semiconductor layer 1153 , and the second conductivity type electrode 1152 is formed on one surface of the second conductivity type semiconductor layer 1153 .

In this case, the second conductivity type electrode is disposed on one surface of the second conductivity type semiconductor layer 1153 , and an undoped semiconductor layer 1153a is formed on the other surface of the second conductivity type semiconductor layer 1153 . ) can be formed.

12 together with FIGS. 10 to 11B , one surface of the second conductivity type semiconductor layer may be the surface closest to the wiring board, and the other surface of the second conductivity type semiconductor layer is closest to the wiring board. It can be on the far side.

In addition, the first conductive electrode 1156 and the second conductive electrode 1152 have a height difference from each other in the width direction and the vertical direction (or thickness direction) at positions spaced apart from each other along the width direction of the semiconductor light emitting device. made to have

The second conductive electrode 1152 is formed on the second conductive semiconductor layer 1153 using the height difference, but is disposed adjacent to the second electrode 1040 positioned above the semiconductor light emitting device. . For example, at least a portion of the second conductivity type electrode 1152 is in the width direction from the side surface of the second conductivity type semiconductor layer 1153 (or the side surface of the undoped semiconductor layer 1153a). protrudes along As described above, since the second conductive electrode 1152 protrudes from the side surface, the second conductive electrode 1152 may be exposed to the upper side of the semiconductor light emitting device. Through this, the second conductive electrode 1152 is disposed at a position overlapping with the second electrode 1040 disposed on the upper side of the conductive adhesive layer 1030 .

More specifically, the semiconductor light emitting device has protrusions 1152a extending from the second conductive electrode 1152 and protruding from side surfaces of the plurality of semiconductor light emitting devices. In this case, when looking at the protrusion 1152a as a reference, the first conductive electrode 1156 and the second conductive electrode 1152 are disposed at positions spaced apart along the protrusion direction of the protrusion 1152a, It can be expressed as being formed to have a height difference from each other in a direction perpendicular to the protrusion direction.

The protrusion 1152a extends laterally from one surface of the second conductivity type semiconductor layer 1153 , and is an upper surface of the second conductivity type semiconductor layer 1153 , more specifically, an undoped semiconductor layer. (1153a). The protrusion 1152a protrudes along the width direction from the side surface of the undoped semiconductor layer 1153a. Accordingly, the protrusion 1152a may be electrically connected to the second electrode 1040 on the opposite side of the first conductivity type electrode with respect to the second conductivity type semiconductor layer.

The structure including the protrusion 1152a may be a structure that can utilize the advantages of the above-described horizontal type semiconductor light emitting device and vertical type semiconductor light emitting device. Meanwhile, in the undoped semiconductor layer 1153a, microgrooves may be formed on the top surface furthest from the first conductive type electrode 1156 by roughing.

According to the display device described above, the light output from the semiconductor light emitting devices is excited using a phosphor to realize red (R) and green (G). Red (R) and green (G) may be implemented in different ways. In the present invention, a display device capable of realizing red (R) and green (G) in a method different from that of the related art is provided.

Hereinafter, a structure of a display device that implements red (R) and green (G) in a new manner will be described in detail with the accompanying drawings.

13 and 14 are cross-sectional views taken along line F-F of FIG. 10 for explaining still another embodiment of the present invention.

13 and 14 , a display device 2000 using the flip chip type semiconductor light emitting device described with reference to FIGS. 10 to 12 is exemplified as a display device using a semiconductor light emitting device. More specifically, a case in which a structure of a new phosphor layer is applied in the flip-chip type semiconductor light emitting device described with reference to FIGS. 10 to 12 is exemplified. However, the examples described below are also applicable to display devices using the other types of semiconductor light emitting devices described above.

In this example to be described below, the same or similar reference numerals are assigned to the same or similar components as those of the examples described with reference to FIGS. 10 to 12 above, and the description is replaced with the first description. For example, the display device 2000 includes a substrate 2010 , a first electrode 2020 , a conductive adhesive layer 2030 , a second electrode 2040 , and a plurality of semiconductor light emitting devices 2050 . The description is replaced by the description with reference to FIGS. 10 to 12 above. Accordingly, in this embodiment, the conductive adhesive layer 2030 is replaced with an adhesive layer, a plurality of semiconductor light emitting devices are attached to the adhesive layer disposed on the substrate 2010 , and the first electrode 2020 is formed on the substrate 2010 . It may be formed integrally with the conductive electrode of the semiconductor light emitting device instead of being located on the .

The second electrode 2040 may be positioned on the conductive adhesive layer 2030 . That is, the conductive adhesive layer 2030 is disposed between the wiring board and the second electrode 2040 . The second electrode 2040 may be electrically connected to the semiconductor light emitting device 2050 by contact.

As described above, the display apparatus 2000 includes a plurality of phosphor layers 2080 disposed to cover the plurality of semiconductor light emitting devices 2050 . Here, the plurality of semiconductor light emitting devices 2050 include a blue semiconductor light emitting device 2051a and a green semiconductor light emitting device 2051b. Specifically, the blue semiconductor light emitting device 2051a is a semiconductor light emitting device that emits blue (B) light, and the green semiconductor light emitting device 2051b is a semiconductor light emitting device that emits green (G) light.

The plurality of phosphor layers 2084 are disposed to cover the green semiconductor light emitting device so as to convert the wavelength of light emitted from the green semiconductor light emitting device 2051b. Meanwhile, the blue semiconductor light emitting device 2051a is not covered with the phosphor layer. Accordingly, the blue light emitted from the blue semiconductor light emitting device 2051a is emitted to the outside without wavelength conversion.

For example, as shown in FIG. 13 , some of the green semiconductor light emitting devices 2051b may be covered with a red phosphor layer 2081 that converts green light emitted from the green semiconductor light emitting device 2051b into red light. . Meanwhile, other green semiconductor light emitting devices other than some of the green semiconductor light emitting devices may not be covered with the phosphor layer. Accordingly, green light emitted from some green semiconductor light emitting devices 2051b is converted into red light and emitted to the outside, and green light emitted from the remaining green semiconductor light emitting devices 2051b can be emitted to the outside without wavelength conversion. have. According to the structure described with reference to FIG. 13 , a red pixel constituting the display device is formed through a green semiconductor light emitting device and a red phosphor, and each of the green and blue pixels is formed through a green semiconductor light emitting device and a blue semiconductor light emitting device.

As another example, as shown in FIG. 14 , some of the green semiconductor light emitting devices 2051b are covered with the above-described red phosphor layer 2081 , and the remaining green semiconductor light emitting devices 2051b are green semiconductor light emitting devices 2051b. It may be covered with a green phosphor layer 2082 that converts the first green light emitted from the light to second green light having a wavelength different from that of the first green light. Accordingly, a portion of the first green light emitted from the green semiconductor light emitting device 2051a is converted into red light and emitted to the outside, and the remainder is converted into second green light having a wavelength different from that of the first green light and emitted to the outside. . According to the structure described with reference to FIG. 14 , a red pixel constituting the display device is formed by a green semiconductor light emitting device and a red phosphor, a green pixel is formed through a green semiconductor light emitting device and a green phosphor, and a blue pixel is formed by a blue semiconductor light emitting device. formed through

Here, the first green light may have a shorter wavelength than the second green light. The longer the wavelength of light emitted from the green semiconductor light emitting device, the higher the ratio of indium in the multi-quantum well. For this reason, uniform growth of the layer becomes difficult. On the other hand, when the indium ratio of the green semiconductor light emitting device is increased for uniform layer growth, the wavelength of green light is shortened and visibility may be deteriorated. The green phosphor layer 2082 converts the first green light into a second green light having high visibility. Through this, it is possible to simultaneously satisfy uniform layer growth and high visibility of the semiconductor light emitting device.

Meanwhile, as shown in FIGS. 13 and 14 , the blue light emitted from the blue semiconductor light emitting device 2051a is emitted to the outside without wavelength conversion.

Meanwhile, the first and second phosphors described with reference to FIGS. 13 and 14 may be formed of organic phosphors or quantum dots. Here, the organic phosphor is an organic material that emits fluorescence. In general, the absorption rate of the organic phosphor for green light is higher than that for blue light. Accordingly, when the green semiconductor light emitting device and the organic phosphor are used, the light conversion efficiency of the phosphor layer can be improved, the thickness of the phosphor layer can be reduced, and the conversion efficiency of the phosphor layer can be increased.

Meanwhile, the plurality of semiconductor light emitting devices according to the present invention form a plurality of pixels. A single pixel includes at least one semiconductor light emitting device, and barrier ribs are formed between the pixels to prevent light from being mixed between the pixels. Meanwhile, as shown in FIG. 15 , each of the pixels 3000 may include a first region in which the semiconductor light emitting device 2050 is disposed and a second region excluding the first region.

When the pixel 3000 has the structure shown in FIG. 15 , the emission area within a single pixel may not be uniform. For example, referring to FIG. 16 , when the semiconductor light emitting device included in the pixel 3000 emits light, a region adjacent to the first region among the first region and the second region may be brighter than the remaining regions. That is, according to the structure described with reference to FIG. 15 , the bright area 3100 and the dark area 3200 are formed even in a single pixel. The present invention provides a structure capable of uniformizing a light emitting area within a pixel.

Hereinafter, a modified example capable of uniformly emitting a light emitting area within a pixel will be described in detail with accompanying drawings.

17a and 17b are cross-sectional views taken along line F-F of FIG. 10 for describing still another embodiment of the present invention.

17A and 17B , at least some of the semiconductor light emitting devices may overlap the scattering layer 2090 . The scattering layer 2090 scatters light emitted from at least some of the semiconductor light emitting devices to proceed to the second region. Accordingly, light is emitted from the entire area of the pixel 3000 . Here, the scattering layer 2090 should be made of a light-transmitting material, and to scatter light, it may be made of a porous material, TiO2, or the like.

For example, as shown in FIG. 17A , in a structure in which a part of the green semiconductor light emitting device 2051b is covered with the red phosphor layer 2081 and the remaining green semiconductor light emitting device 2051b is not covered with the phosphor layer, The scattering layer 2090 may be disposed between the red phosphor layer 2081 and the green semiconductor light emitting device 2051b. That is, the scattering layer 2090 overlaps the semiconductor light emitting device covered with the phosphor layer.

As another example, as shown in FIG. 17B , a part of the green semiconductor light emitting device 2051b is covered with the red phosphor layer 2081 , and the remaining green semiconductor light emitting device 2051b is covered with the green phosphor layer 2082 . In the structure, the scattering layer 2090 may be disposed between the red phosphor layer 2081 and the green semiconductor light emitting device and between the second fluorescent layer 2082 and the green semiconductor light emitting device, respectively. That is, the scattering layer 2090 may overlap all the semiconductor light emitting devices covered with the phosphor layer.

Meanwhile, the area of the phosphor layer may be larger than that of the semiconductor light emitting device. In this case, light emitted from the semiconductor light emitting device may be absorbed only in a partial region of the phosphor layer. Due to this, the light absorption rate of the phosphor layer may be reduced. If the scattering layer is used, the light emitted from the semiconductor light emitting device may travel to the entire area of the phosphor layer, and thus the light absorption rate of the phosphor layer may be improved.

According to the new structure described above, it is possible to provide a display device in which the thickness of the phosphor layer is reduced and light is evenly emitted over the entire pixel area. Hereinafter, a manufacturing method of forming the new phosphor layer structure described above will be described in more detail with accompanying drawings. 18A to 18C and 19A to 19D are cross-sectional views illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.

18A to 18C are views for explaining a method of manufacturing a display device using a semiconductor light emitting device of the present invention with reference to cross-sectional views taken in the direction E-E of FIG. A diagram for explaining a method of manufacturing a display device using a semiconductor light emitting device of

First, according to the manufacturing method, a step of coupling a plurality of semiconductor light emitting devices to a substrate is performed. For example, a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer are grown on a growth substrate, and each semiconductor light emitting device is generated through etching, followed by the first conductivity type electrode 2156 and the second conductivity type semiconductor layer. An electrode 2152 is formed (FIG. 18A).

The growth substrate 2101 (wafer) may be formed of a material having a light-transmitting property, for example, any one of sapphire (Al2O3), GaN, ZnO, and AlO, but is not limited thereto. In addition, the growth substrate 2101 may be formed of a carrier wafer, a material suitable for semiconductor material growth. It may be formed of a material having excellent thermal conductivity, and, including a conductive substrate or an insulating substrate, for example, a SiC substrate having higher thermal conductivity than a sapphire (Al2O3) substrate or at least one of Si, GaAs, GaP, InP, Ga2O3 Can be used.

The first conductive electrode 2156 and the first conductive semiconductor layer may be a p-type electrode and a p-type semiconductor layer, respectively, and the second conductive electrode 2152 and the second conductive semiconductor layer are each an n-type electrode. and an n-type semiconductor layer. However, the present invention is not necessarily limited thereto, and examples in which the first conductivity type is n-type and the second conductivity type is p-type are also possible.

In this case, as described above, at least a portion of the second conductivity type electrode 2152 protrudes from the side surface of the second conductivity type semiconductor layer (or the side surface of the undoped semiconductor layer 2153a). do.

Next, the flip chip type light emitting device is bonded to a wiring board using a conductive adhesive layer 2030, and the growth substrate is removed (FIG. 18B).

The wiring board is in a state in which the first electrode 2020 is formed, and the first electrode 2020 is electrically connected to the first conductive electrode 2156 by a conductive ball in the conductive adhesive layer 2030 as a lower wiring. do.

Thereafter, after removing the undoped semiconductor layer 2153a by etching, a second electrode 2040 connecting the protruding second conductivity type electrode 2152 is formed ( FIG. 18C ). The second electrode 2040 is an upper wiring and is directly connected to the second conductive electrode 2152 .

However, the present invention is not necessarily limited thereto, and the undoped semiconductor layer may be replaced with another type of absorption layer that absorbs UV laser. The absorption layer may be a buffer layer, is formed in a low-temperature atmosphere, and may be made of a material capable of alleviating a difference in lattice constant between the semiconductor layer and the growth substrate. For example, it may include materials such as GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN.

Next, a scattering layer disposed to cover some of the plurality of semiconductor light emitting devices is formed. As illustrated, first, referring to FIG. 19A , a step of applying a light-transmitting material LT to the plurality of semiconductor light emitting devices may be performed.

The light-transmitting material LT is a material having high transmittance in the visible light region, and as described above, an epoxy-based photoresist (PR), polydimethylsiloxane (PDMS), resin, or the like may be used.

After that, the light-transmitting material is etched, and the scattering material is filled in the etched portion of the light-transmitting material LT to generate the scattering layer.

More specifically, according to FIG. 19B , the light-transmitting material LT is etched, and by the etching, the light-transmitting material LT is disposed to cover between the plurality of semiconductor light emitting devices. Accordingly, a scattering layer may be formed between the light-transmitting materials.

Referring to FIG. 19C , after the light-transmitting material is etched, a step of forming a scattering layer on the light-transmitting material LT is performed. In this case, the scattering layer 2090 may be formed only in a region corresponding to the green semiconductor light emitting device 2051b to be covered with the phosphor layer.

Here, the scattering layer 2090 should be made of a light-transmitting material, and to scatter light, it may be made of a porous material, TiO2, or the like.

Thereafter, as shown in FIG. 19D , the phosphor layer is formed by filling the phosphor layer between the light-transmitting material on which the scattering layer is formed.

As an example of generating the phosphor layer, a method of sequentially coating a red phosphor and a green phosphor after coating and developing a photoresist may be used.

The display device using the semiconductor light emitting device described above is not limited to the configuration and method of the above-described embodiments, but all or part of each embodiment may be selectively combined so that various modifications may be made. may be

Claims (11)

a substrate on which wiring electrodes are formed;
a plurality of semiconductor light emitting devices electrically connected to the wiring electrode; and
a plurality of phosphor layers disposed to cover the plurality of semiconductor light emitting devices to convert wavelengths of light emitted from the plurality of semiconductor light emitting devices; and
The plurality of semiconductor light emitting devices are provided with blue semiconductor light emitting devices and green semiconductor light emitting devices,
The plurality of phosphor layers includes a red phosphor layer that absorbs light and converts it into red light, and a green phosphor layer that absorbs light and converts it into green light,
The red phosphor layer is disposed to cover some of the green semiconductor light emitting devices so that red light is output through the green semiconductor light emitting devices,
The green phosphor layer is disposed to cover some of the green semiconductor light emitting devices so that green light having a wavelength converted is output through the green semiconductor light emitting devices,
The wavelengths of the green light converted by the green phosphor layer and the green light emitted from the green semiconductor light emitting device are different from each other,
A wavelength of green light converted by the green phosphor layer is longer than a wavelength of green light emitted from the green semiconductor light emitting device. delete delete According to claim 1,
The light absorptivity of the phosphor layers with respect to green light is higher than that of the blue light of the phosphor layers. According to claim 1,
The plurality of semiconductor light emitting devices form a plurality of pixels,
Each of the plurality of pixels,
a first region in which a semiconductor light emitting device is disposed; and
and a second area excluding the first area. 6. The method of claim 5,
and a scattering layer overlapping the at least a portion so that light emitted from at least some of the semiconductor light emitting devices is emitted from the second region to the outside. 7. The method of claim 6,
The scattering layers are
The display device, characterized in that it is disposed to cover the green semiconductor light emitting device. 7. The method of claim 6,
The scattering layers are
The display device, characterized in that it is disposed between the at least part and the phosphor layer covering the at least part. 7. The method of claim 6,
The scattering layer is a display device, characterized in that made of a porous material or TiO2. According to claim 1,
The phosphor layer is a display device, characterized in that made of an organic phosphor. delete

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