KR102439186B1 - Display device using semiconductor light emitting device - Google Patents

Abstract

The present invention relates to a display device, and more particularly, to a display device using a semiconductor light emitting device and a method for manufacturing the same. A display device according to the present invention includes at least one semiconductor light emitting device coupled to a substrate, the substrate having a through hole, a base body formed of an insulating material, and an annular shape formed with the semiconductor light emitting device; and a solder disposed on one surface of the base body so that the annular hollow portion overlaps the through hole, and a metal portion configured to fill the through hole.

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 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 flexible, and in the case of AMOLED, there are weaknesses in that the lifespan is short and the mass production yield is not good.

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 display using the semiconductor light emitting device can be proposed.

As such, in the case of a display using a semiconductor light emitting device, it is difficult to implement a display device having a large screen. Accordingly, recently, a manufacturing method in which a semiconductor light emitting device is coupled to a substrate by a self-assembly method has been developed.

However, since the self-assembly method depends on the surface tension of the conductive electrode and the solder of the semiconductor light emitting device, there is a disadvantage in that the assembly efficiency is lowered. In addition, a weak disadvantage in terms of reliability may occur due to a structure in which heat is concentrated. Therefore, it can be considered for a mechanism that can alleviate these disadvantages in the self-assembly method.

SUMMARY OF THE INVENTION One object of the present invention is to provide a structure capable of improving assembly efficiency in self-assembly of a semiconductor light emitting device in a display device.

Another object of the present invention is to provide a display device using a semiconductor light emitting device having a heat dissipation structure.

The present invention provides a structure in which flow is induced through a hole, and thus semiconductor light emitting devices are moved to an assembly area, thereby improving assembly rate. In addition, after bonding the semiconductor light emitting device to the substrate with solder, additional bonding is implemented by an electroplating method to realize a heat dissipation structure.

Specifically, the display device according to the present invention includes at least one semiconductor light emitting device coupled to a substrate, the substrate having a through hole, a base body formed of an insulating material, and an annular shape of the semiconductor It is coupled to the light emitting device and includes a solder disposed on one surface of the base body so that the annular hollow portion overlaps the through hole, and a metal portion configured to fill the through hole.

In an embodiment, the metal part protrudes toward the semiconductor light emitting device from the entrance of the through hole. The metal part may pass through the hollow part through the protrusion to lead to the conductive electrode of the semiconductor light emitting device.

In an embodiment, the metal part is made of a plated metal material. The metal part may include a first metal material applied to the inner wall of the through hole, and a second metal material plated on the first metal material to fill the through hole. The first metal material may include a first portion covering the conductive electrode of the semiconductor light emitting device, and a second portion formed in a direction perpendicular to the first portion and formed on an inner wall of the through hole.

In an embodiment, an anti-oxidation layer covering the metal part is formed on the other surface of the base body.

In an embodiment, a reflective layer is formed on one surface of the base body. A reflective through-hole corresponding to the through-hole may be formed in the reflective layer, and the metal part may be configured to fill the reflective through-hole. A metal layer may be formed on the reflective layer along an outer periphery of the through hole, and the solder may be laminated on the metal layer.

In an embodiment, the semiconductor light emitting device includes a conductive semiconductor layer, a conductive electrode formed on one surface of the conductive semiconductor layer, and a passivation layer surrounding at least a portion of the semiconductor light emitting device, the through The hole has a size smaller than that of the conductive electrode. The conductive electrode may include a first annular region in contact with the solder, and a second region in contact with the metal portion and formed inside the first region.

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The conventional self-assembly method was implemented by probability depending on the surface tension between the bonding metal and the conductive electrode, but in the present invention, the flow is induced through the annular solder and the through hole of the substrate, and thus the semiconductor The light emitting device may be moved toward the solder. Through this, in the present invention, the assembly efficiency of the semiconductor light emitting device can be improved in self-assembly.

In addition, in the present invention, after bonding the semiconductor light emitting device to the substrate with solder, additional bonding is implemented through an electroplating method, so that bonding reliability can be further improved. In addition, according to this structure, since the metal is filled in the through hole, heat dissipation can be more easily achieved.

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 portion A of FIG. 1 for explaining another embodiment of the present invention to which a semiconductor light emitting device and a wiring board having a new structure are applied.
11 is a cross-sectional view taken along line EE of FIG. 10/
FIG. 12A is an enlarged view of part B of FIG. 11 , and FIG. 12B is an exploded enlarged view of a semiconductor light emitting device disassembled from a wiring board.
13 is an enlarged view of part B of FIG. 11 showing another embodiment of the present invention.
14, 15 and 16 are conceptual views illustrating a method of manufacturing a display device according to 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 positioned.

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 231 and a non-conductive portion 232 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 is possible to reduce the size of a chip because electrodes can be arranged vertically.

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 device 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 realized by the semiconductor light emitting device.

In the display device using the semiconductor light emitting device of the present invention described above, the semiconductor light emitting device grown on a wafer and formed through mesa and isolation is used as an individual pixel. Since it is a method of transferring a semiconductor light emitting device grown on a wafer to a wiring board, there is a problem in that it is difficult to implement a large screen display due to the size limitation of the wafer. In order to solve this problem, a method of assembling a semiconductor light emitting device using a wiring board using a self-assembly method may be applied.

The self-assembly method is a method in which semiconductor light emitting devices are mounted on a wiring board or an assembly board in a chamber filled with a fluid. For example, the semiconductor light emitting devices and the substrate are put into a chamber filled with a fluid, and the fluid is heated so that the semiconductor light emitting devices are self-assembled on the substrate. To this end, the substrate may be provided with grooves into which the semiconductor light emitting devices are inserted. Specifically, grooves in which the semiconductor light emitting devices are seated are formed in the substrate at positions where the semiconductor light emitting devices are aligned with the wiring electrodes. The grooves have a shape corresponding to the shape of the semiconductor light emitting devices, and the semiconductor light emitting devices move randomly in the fluid and are assembled into the grooves.

In addition, in the case of realizing a large screen in the self-assembly method, the luminous efficiency can be improved by self-assembling each of the red semiconductor light emitting device, the green semiconductor light emitting device, and the blue semiconductor light emitting device without using a phosphor or a color filter. .

In the present invention, a structure for improving the assembly efficiency of semiconductor light emitting devices and a new heat dissipation structure are provided. However, in the display device to be described below, the structure for improving the assembly efficiency and the new heat dissipation structure may be implemented independently of each other.

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 and a wiring board are applied, and FIG. 11 is a cross-sectional view taken along line E-E of FIG. 12A is an enlarged view of part B of FIG. 11 , and FIG. 12B is an exploded enlarged view of a semiconductor light emitting device disassembled from a wiring board.

10, 11, 12A and 12B, a display device 1000 using a passive matrix (PM) type vertical semiconductor light emitting device as a display device 1000 using a semiconductor light emitting device is provided. exemplify 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 , an insulating layer 1060 , a plurality of semiconductor light emitting devices 1050 , and a second electrode 1040 . 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 the first electrode 1020 is positioned on the substrate 1010 and may be formed as an electrode in the form of a bar long in one direction. have. The first electrode 1020 may serve as a data electrode.

The first electrode 1020 is a lower wiring electrode and is bonded to the p-type electrode of the semiconductor light emitting device through an electric wiring, and the main element at the top of the electrode is a single component of Au, Cu, In, Sn or 2, 3, A mixture of quaternary components is possible. In this case, the electrode may have a thickness of 50 nanometers or more in order to lower the resistance.

Meanwhile, referring to the drawings, between the semiconductor light emitting devices, a plurality of second electrodes ( 1040) is located.

As illustrated, the second electrode 1040 may be positioned on the insulating layer 1060 . More specifically, an insulating material is filled between the semiconductor light emitting devices to form an insulating layer 1060 , and a second electrode 1040 serving as an upper wiring is disposed on one surface of the insulating layer 1060 .

The insulating layer 1060 is made of an insulating and flexible material such as polyimide (PI, Polyimide), PET, PEN, PDMS, PMPS, etc., and is integrally formed with the substrate 1010 to form a single wiring board. have.

As a more specific example, the insulating layer 1060 may be a PDMS & PMPS mixture (0 ≤ PDMS ≤ 100) containing a transparent resin or a white material. By the insulating layer, the chip is protected from the external environment, and further, the light extraction efficiency can be improved.

In this case, the second electrode 1040 may be electrically connected to the second conductive electrode 1152 of 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 wiring board 1010 and electrically connected to the first electrode 1020 and the second electrode 1040 .

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 .

As illustrated, the semiconductor light emitting device 1050 includes a red semiconductor light emitting device 1051 , a green semiconductor light emitting device 1052 , and a blue semiconductor light emitting device 1053 .

However, the present invention is not necessarily limited to the above structure. For example, the red semiconductor light emitting device 1051 may be replaced with a green semiconductor light emitting device 1052 or a blue semiconductor light emitting device 1053 . For example, in the semiconductor light emitting device, two blue semiconductor light emitting devices 1053 and one green semiconductor light emitting device 1052 may form one pixel, and in this case, any one of the blue semiconductor light emitting devices 1053 is A blue sub-pixel and the other one may form a red sub-pixel.

For example, a phosphor layer (not shown) may overlap the upper surface of the blue semiconductor light emitting device 1053 . The phosphor layer converts the blue light into the color of the unit pixel. The phosphor layer includes a red phosphor, and converts blue light from a blue semiconductor light emitting device into red light in a red sub-pixel. In addition, a red color filter (not shown) for filtering a wavelength range other than light corresponding to red light may be overlapped on the upper surface of the phosphor layer to improve color purity.

As another example, it is also possible to configure the display device using only the blue semiconductor light emitting device. In this case, the semiconductor light emitting device 1050 includes only the blue semiconductor light emitting device, and red and green phosphor layers (not shown) may be overlapped on the upper surface of the blue semiconductor light emitting device 1053 .

The structures of the red semiconductor light emitting device 1051 , the green semiconductor light emitting device 1052 , and the blue semiconductor light emitting device 1053 to be described below are the same and will be described with reference to FIG. 12A . In addition, the structure of the semiconductor light emitting device to be described below may be applied to, for example, a case of configuring a display device using only blue semiconductor light emitting devices or using only blue and green semiconductor light emitting devices.

The semiconductor light emitting device may be referred to as a micro LED, and has an area of 25 to 250000 micrometers square, and the thickness of the chip may be about 2 to 10 micrometers,

Referring to FIG. 12A , for example, the semiconductor light emitting device 1050 includes a first conductivity type electrode 1156 and a first conductivity type semiconductor layer 1155 on which the first conductivity type 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.

The first conductivity type semiconductor layer 1155 and the second conductivity type semiconductor layer 1153 overlap each other, and a second conductivity type electrode 1152 is disposed on the upper surface of the second conductivity type semiconductor layer 1153 , A first conductivity type electrode 1156 is disposed on a lower surface of the first conductivity type semiconductor layer 1155 . In this case, the upper surface of the second conductivity type semiconductor layer 1153 is one surface of the second conductivity type semiconductor layer 1153 furthest from the first conductivity type semiconductor layer 1155, and the first conductivity type semiconductor layer ( The lower surface of 1155 may be one surface of the first conductivity type semiconductor layer 1155 furthest from the second conductivity type semiconductor layer 1153 . As described above, the first conductivity type electrode 1156 and the second conductivity type electrode 1152 are vertically disposed with the first conductivity type semiconductor layer 1155 and the second conductivity type semiconductor layer 1153 interposed therebetween, respectively. are placed

Referring to FIG. 12 together with FIGS. 10 and 11 , the lower surface of the first conductivity type semiconductor layer 1155 may be the surface closest to the wiring board, and the upper surface of the second conductivity type semiconductor layer 1153 . may be a surface furthest from the wiring board.

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.

The p-type semiconductor layer may be P-type GaAs, and the n-type semiconductor layer may be N-type GaAs. However, in the case of the green semiconductor light emitting device and the blue semiconductor light emitting device, the p-type semiconductor layer may be P-type GaN, and the n-type semiconductor layer may be N-type GaN. Also, in this example, the p-type semiconductor layer may be P-type GaN doped with Mg on the p-electrode side, and the n-type semiconductor layer may be N-type GaN doped with Si on the n-electrode side. In this case, the above-described semiconductor light emitting devices may be semiconductor light emitting devices without an active layer. Furthermore, in the embodiment described below, the semiconductor light emitting devices are exemplified as having an active layer, but the p-type semiconductor layer is P-type GaN doped with Mg on the p-electrode side, and the n-type semiconductor layer has Si on the n-electrode side. A structure without an active layer being doped N-type GaN can be applied.

In this case, the conductive semiconductor layer has an area range of 25 to 250000 micrometers square, and a thickness of about 2 to 10 micrometers.

In this case, the lower p-type electrode may be electrically connected to the first electrode 1020 by solder or a metal part, and the upper n-type electrode may be electrically connected to the second electrode 1040 . In this case, the p-type electrode may include a plurality of metal layers made of different metals. For example, a plurality of metal layers made of Ti, Pt, Au, Ti, Cr, etc. may be stacked to form the p-type electrode.

More specifically, the p-type electrode is bonded on Mg-doped GaN, and may be made of Au, Cu, or a mixture thereof. The area may be 30 to 75% of the GaN epitaxial area, and the electrode may be disposed at the exact center of the GaN epitaxial area. The shape of the electrode is preferably a circle, but if necessary, a polygon of more than a square is also possible. Here, the area and shape of the p-type electrode refer to only a portion of the open p-type electrode that is not covered by the passivation layer. In this case, the net area of the p-type electrode is between the area of the part of the p-type electrode that is turned off and the total area of the GaN epi. In addition, in order to improve bonding strength between GaN and Au or Cu, Ti, Cr, or Pt layers may be added to the interface thereof. The overall thickness of the p-type electrode may be 100 nanometers to 5 micrometers.

In this case, the semiconductor light emitting device includes a passivation layer 1160 formed to surround side surfaces of the first conductivity type semiconductor layer 1155 and the second conductivity type semiconductor layer 1153 .

The passivation layer 1160 surrounds the side surface of the semiconductor light emitting device to stabilize characteristics of the semiconductor light emitting device, and is formed of an insulating material. As described above, since the first conductivity type semiconductor layer 1155 and the second conductivity type semiconductor layer 1153 are electrically cut off by the passivation layer 1160, P-type GaN and N of the semiconductor light emitting device -type GaN can be insulated from each other.

In this case, the passivation layer 1160 has an exposure hole 1161 to expose the first conductive type electrode 1156 . At least a portion of a solder 1071 and a metal part 1080, which will be described later, is inserted into the exposed hole 1161, through which the semiconductor light emitting device can be coupled to the wiring board. At this time, when the semiconductor light emitting device is self-assembled, the wiring board is immersed in a fluid in a state in which the solder 1071 is melted. As the solder 1071 is solidified, the solder 1071 and the conductive electrode are coupled to each other, and thereafter, the metal part 1080 is plated so that the metal part and the conductive electrode are secondarily coupled.

The lower surface of the passivation layer 1160 may protrude from the lower surface of the conductive electrode so as to limit contact of the conductive electrode of any one of the plurality of semiconductor light emitting devices with the other conductive electrode during self-assembly. have. Specifically, the passivation layer 1160 covers the lower surface (the surface furthest from the conductive semiconductor layer) of the first conductive type electrode 1156 , and the first conductive type electrode 1156 has the exposed hole 1161 . It can be a structure that does not penetrate through. According to this structure, the first conductive type electrode 1156 is covered by the passivation layer 1160 in an intaglio shape, and the solder 1071 penetrates the exposed 1161 to the first conductive type electrode 1160 . It is coupled to the electrode 1156 .

The material of the passivation layer 1160 may be SiO2 or SiNx, and covers all side surfaces of the GaN epitaxial layer and exposes the central portion of the conductive electrode. The lower surface is formed to cover all portions of the p-type electrode or GaN epitaxial layer except for the portion of the p-type electrode exposed to the outside. The passivation layer has a thickness of 50 nanometers to 5 micrometers, and the thickness of the lower surface and the thickness of the side surface may be different from each other.

Meanwhile, the red semiconductor light emitting device 1051 , the green semiconductor light emitting device 1052 , and the blue semiconductor light emitting device 1053 have a structure electrically connected to the solder 1071 and the metal part 1080 through self-assembly. .

10 to 12B , the substrate 1010 includes a base body 1011 formed of an insulating material. The base body 1011 may include polyimide (PI) to implement a flexible display device. In addition, any material that has insulating properties and is flexible may be used.

In this case, a plurality of through holes 1012 corresponding to each of the plurality of semiconductor light emitting devices may be formed in the base body 1011 . The through hole 1012 may be a hole extending from one surface to the other surface of the base body 1011 , which functions as a passage through which a fluid may flow during self-assembly of the semiconductor light emitting device.

The solder 1071 may be disposed on the base body 1011 . The solder 1071 may be formed in an annular shape to be coupled to the semiconductor light emitting device, and may be disposed on one surface of the base body 1011 such that the annular hollow portion overlaps the through hole 1012 . Through this, the solder 1071 implements a passage through which a fluid can flow together with the through hole 1012 . In this case, the first electrode 1020 is disposed on the other surface of the base body 1011 to form a lower wiring of the semiconductor light emitting device. In this case, the through hole 1012 may have a size smaller than that of the first conductive electrode 1156 of the semiconductor light emitting device.

The solder 1071 is an auxiliary electrode electrically connecting the first electrode 1020 and the semiconductor light emitting device 1050 , and is disposed to correspond to the position of the through hole 1012 . For example, the solder 1071 may have a donut shape, and may be electrically connected to the first electrode 1020 by the metal part 1080 filled in the through hole 1012 .

For example, the solder 1071 may be formed of a material having a low melting point, and may be applied to the substrate in a dot shape. More specifically, the semiconductor light emitting device 1050 is electrically and physically connected to the substrate through soldering using the solder 1071 . Soldering means bonding metals together using solder, flux, and heat. The solder material may be, for example, at least one of Sn, Ag, Cu, Pb, Al, Bi, Cd, Fe, In, Ni, Sb, Zn, Co, and Au.

Meanwhile, as illustrated, a reflective layer 1013 may be formed on one surface of the base body 1011 . The reflective layer 1013 may be formed by depositing a high reflective material on one surface of the base body 1011 to function as a reflector.

In this case, a reflective through-hole 1014 corresponding to the through-hole 1012 is formed in the reflective layer 1013 to form a passage through which the fluid flows. In addition, a metal layer 1072 may be formed on the reflective layer 1013 along the outer periphery of the through hole 1012 , and the solder 1071 may be stacked on the metal layer 1072 .

The metal layer 1072 is an under bump metallurgy (UBM) layer having a size smaller than or equal to that of the first conductive electrode 1156 of the semiconductor light emitting device, and is formed in an annular shape. The UBM layer serves as a buffer for external forces when assembling and driving a semiconductor light emitting device in the future as a place where solder is to be located. Through this, durability and reliability of the display device may be improved.

In addition, the hollow part of the solder 1071, the hollow part of the metal layer 1072, the reflective through-hole 1014, and the through-hole 1012 overlap in sequence, and through this, the flow passage of the fluid is formed during self-assembly. can be formed.

Meanwhile, the metal part 1080 is configured to fill the through hole 1012 . Furthermore, the metal part 1080 protrudes from the entrance of the through hole 1012 toward the semiconductor light emitting device, fills the reflective through hole 1014 through the protrusion, and forms a hollow portion of the metal layer 1072 and It passes through the hollow part of the solder 1071 and leads to the conductive electrode of the semiconductor light emitting device.

Since the first conductive electrode 1156 of the semiconductor light emitting device contacts the solder 1071 and the metal part 1080, respectively, it may be divided into a first region 1156a and a second region 1156b. As shown, the first area 1156a is an annular area in contact with the solder 1071 , and the second area 1156b is in contact with the metal part 1080 and the first area 1156a is in contact with the metal part 1080 . It may be a region formed on the inside of

More specifically, at least a part of the metal part 1080 is made of a plated metal material, and the through-hole 1012 and the reflective through-hole 1014 are filled through plating. For example, the metal part 1080 is formed of a first metal material 1081 applied to the inner wall of the through hole 1012 and the first metal material 1081 to fill the through hole 1012 . A plated second metal material 1082 may be provided.

The first metal material 1081 becomes a seed layer for an electroplating process, and for example, copper or the like may be formed in the through hole 1012 and a portion of the semiconductor light emitting device by sputtering. . For example, the first metal material 1081 may include a first portion 1081a covering the conductive electrode of the semiconductor light emitting device and formed in a direction perpendicular to the first portion 1081a to form the through hole 1012 . ) may be provided with a second portion (1081b) formed on the inner wall. More specifically, the first portion 1081a covers a portion surrounded by the solder in the first conductive electrode of the semiconductor light emitting device. The second portion 1081b extends from the edge of the first portion 1081a toward the substrate, and covers the hollow portion of solder, the hollow portion of the metal layer, the reflective through-hole, and inner walls of the through-hole.

The second metal material 1082 is formed as a plated material, and through electroplating, the conductive electrode region of the semiconductor light emitting device is covered with a material having high thermal and electrical conductivity, such as copper. In this case, when the first metal material 1081 and the second metal material 1082 are the same material, the first metal material 1081 and the second metal material 1082 are integrated with each other, and the first part The distinction between the 1081a and the second portion 1081b may be lost.

In this way, a passage of fluid is made using annular solder and through-holes, and the bonding process is performed in a self-assembly method through this, and then secondary metal bonding is performed through an electroplating method, thereby improving the heat dissipation effect. can

Meanwhile, the solder and metal parts described above may be deformed in various forms. Hereinafter, an example of such a modification is demonstrated.

13 is an enlarged view of part B of FIG. 11 showing another embodiment of the present invention.

In the example of FIG. 13 , the same reference numerals are assigned to the same components as those of the examples described above with reference to FIGS. 10 to 12 , and the description is replaced with the first description. Specifically, the configuration other than the solder and the metal part is the same as the configuration of the example described with reference to FIGS. 10 to 12 .

Referring to this figure, the upper surface of the solder 2071 may be a closed surface having no hollow portion. That is, the solder 2071 includes a base portion 2071a covering the conductive electrode 2156 of the semiconductor light emitting device, and an annular protrusion portion 2071b protruding from the base portion 2071a.

There is no opening in the base portion 2071a , so the solder 2071 completely covers the conductive electrode 2156 . At this time, the upper side of the solder 2071 with the base portion 2071a is fitted into the exposed hole 2161 of the passivation layer 2160 of the semiconductor light emitting device.

According to this structure, the metal part 2080 fills the inside of the annular protrusion part 2071b to cover the lower surface of the base part 2071a. Accordingly, a structure in which the primary bonding metal is bonded to the entire conductive electrode and the secondary bonding metal is bonded to the primary bonding metal may be formed.

The solder 2071 is applied in an annular shape during self-assembly of the semiconductor light emitting device, and when the conductive electrode of the semiconductor light emitting device is seated, the solder 2071 is pressed by the conductive electrode, through which the solder 2071 may have a base portion.

In addition, an oxidation prevention layer 2090 covering the metal part 2080 may be formed on the other surface of the base body 2011 of the substrate 2010 . The antioxidant layer 2090 may be deposited on the base body 2011 in various ways. In this case, the above-described first electrode is not formed on the substrate, and the lower wiring may be implemented in another way.

According to the structure described above, after bonding the semiconductor light emitting device to the substrate with solder, additional bonding is implemented by an electroplating method, so that bonding reliability can be further improved. In addition, according to this structure, since the metal is filled in the through hole, heat dissipation can be more easily achieved.

Hereinafter, a method of manufacturing a display device using a semiconductor light emitting device having the above-described structure will be described in more detail with accompanying drawings. 14, 15 and 16 are conceptual views illustrating a method of manufacturing a display device according to the present invention.

First, according to the manufacturing method, a second conductivity type semiconductor layer 1153 , an active layer 1154 , and a first conductivity type semiconductor layer 1155 are grown on a growth substrate 1200 (wafer), respectively (FIG. 14(a)). ).

After the second conductivity type semiconductor layer 1153 is grown, an active layer 1154 is grown on the second conductivity type semiconductor layer 1153 , and then a first conductivity type semiconductor is grown on the active layer 1154 . Layer 1155 is grown.

In this way, when the second conductivity type semiconductor layer 1153, the active layer 1154, and the first conductivity type semiconductor layer 1155 are sequentially grown, as shown in FIG. A layered structure is formed. In this case, an undoped semiconductor layer 1153a may be formed between the second conductivity type semiconductor layer 1153 and the growth substrate.

The growth substrate 1200 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 1200 may be formed of a material suitable for semiconductor material growth, a carrier wafer. 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.

Next, isolation is performed so that a plurality of light emitting devices form a light emitting device array on the growth substrate 1200 . That is, the first conductivity type semiconductor layer 1155 , the active layer 1154 , and the second conductivity type semiconductor layer 1153 are etched to form a plurality of semiconductor light emitting devices ( FIG. 14B ).

Next, as shown in FIG. 14C , a first conductive electrode 1156 is formed on the first conductive semiconductor layer 1155 exposed to the outside, as shown in FIG. 14D . As described above, a passivation layer 1160 formed to surround the semiconductor light emitting device is formed.

In this case, the green semiconductor light emitting device and the blue semiconductor light emitting device may be separately grown on the growth substrate so that the light emitting structures of the green semiconductor light emitting device and the blue semiconductor light emitting device are grown. In addition, the red semiconductor light emitting device may be grown on a separate growth substrate so that the light emitting structure of the red semiconductor light emitting device is grown.

Next, as shown in FIG. 15 , the semiconductor light emitting device 1050 is separated from the growth substrate, and sequentially coupled to the substrate 1010 through self-assembly in a chamber filled with a fluid.

Referring to (a) of FIG. 15 , first, semiconductor light emitting devices 1050 and a substrate 1010 are put into a chamber filled with a fluid, and the fluid is heated so that the semiconductor light emitting devices 1050 are attached to the substrate 1010 . self-assemble.

In this case, as described above, the substrate 1010 may include a base body 1011 formed of an insulating material, and a reflective layer 1013 may be formed on one surface of the base body. A through hole 1012 may be formed in the base body 1011 , and a reflection through hole 1014 may be formed in the reflective layer 1013 . In addition, a metal layer 1072 is formed on the reflective layer 1013 along the outer periphery of the through hole 1012 , and a solder 1071 is laminated on the metal layer 1072 (above, refer to (b) of FIG. 15 )). can be Each of the metal layer and the solder may be formed in an annular shape.

In this case, the hollow part of the solder 1071, the hollow part of the metal layer 1072, the reflective through-hole 1014, and the through-hole 1012 overlap in sequence, through which the fluid flows during self-assembly. A passage may be formed. In addition, a drainage device is provided so that a flow can be uniformly formed in the lower part of the container in which the chips are dispersed, and the moving in and down directions are applied to the substrate in the opposite direction. Furthermore, an external motion such as sonication may be applied to move the chip in the fluid. However, in addition to the method of dispersing the chip in the fluid, the present method can be implemented by dispersing the chip in advance on the substrate.

As described above, when the substrate on which the via hole and the primary bonding metal are formed is placed in the fluid in which the semiconductor light emitting device is dispersed and flow is generated, the movement of the semiconductor light emitting device is induced and self-assembly is performed. Since the fluid in the chamber flows through the through hole 1012 to guide the semiconductor light emitting device to the solder 1071, it is hereinafter referred to as a liquid flow induced method. At this time, acid and heat may be applied to the fluid to break the oxide film of the solder 1071 and maintain the liquid.

Referring to (b) of FIG. 15 , a semiconductor light emitting device is primarily assembled on a solder 1071 that is a primary bonding metal through a flow induction method. In this case, the solder 1071 may be bonded to the chip over a portion or the entire surface of the conductive electrode of the semiconductor light emitting device.

Referring to (c) of FIG. 15 , a PDMS & PMPS mixture (0 ≤ PDMS ≤ 100) containing a transparent resin or white material may be coated on the substrate on which the semiconductor light emitting device is assembled through the flow induction method. This is the purpose of not only protecting the chip from the plating process of the secondary bonding metal in the future and the external environment, but also improving the light extraction efficiency. The above-described insulating layer 1060 may be formed by the coated PDMS & PMPS mixture.

Next, heat dissipation and lower wiring processes may be performed. 16 (a) and (b), the step of filling the metal portion 1080, the step of sputtering a first metal material 1081 on the inner wall of the through hole 1012, the Filling the through hole 1012 by plating the second metal material 1082 on the first metal material 1081 may be included.

First, a seed layer for electroplating is formed as shown in (a) of FIG. 16 , and the seed layer is a hollow portion of the solder 1071 and a hollow portion of the metal layer 1072 using a first metal material 1081 such as copper. The portion, the reflection through hole 1013 and the inner wall of the through hole 1012 and a portion of the semiconductor light emitting device may be formed by sputtering.

Next, the electrode region of the semiconductor light emitting device is filled with a second metal material 1082, for example, a material having high thermal and electrical conductivity, such as copper, through electroplating (refer to FIG. 16(b) ). Through this plating, the above-described metal part 1080 may be implemented.

When the first metal material 1081 and the second metal material 1082 are the same material, the metal part 1080 is a single unit having no boundary between the first metal material 1081 and the second metal material 1082 . It can be a metal part.

Thereafter, a first electrode 1020 is formed on the lower surface of the base body to be connected to the metal part 1080 (refer to FIG. 16(c) ). Through this, the lower wiring is implemented.

Finally, as shown in (d) of FIG. 16 , an undoped semiconductor layer 1153a is removed to form an upper wiring to expose the second conductivity type semiconductor layer to the outside, and thereafter, the second conductivity type semiconductor layer is removed. An electrode 1152 is formed, and a second electrode 1040 serving as an upper wiring is deposited.

The second electrode 1040 is a material having low light absorption and high transmittance, and may include, for example, ITO, Ag nanowire, conductive polymer, or the like. After that, in order to improve the light extraction efficiency and protect the semiconductor light emitting device, an encapsulation resin such as silicon may be applied.

According to the manufacturing method described above, a structure in which bonding reliability is further improved and heat dissipation is easier can be applied to a display device using a semiconductor light emitting device.

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 (15)

A display device comprising at least one semiconductor light emitting device coupled to a substrate, the display device comprising:
The substrate is
a base body having a through hole and formed of an insulating material;
a solder formed in an annular shape, coupled to the semiconductor light emitting device, and disposed on one surface of the base body such that the annular hollow portion overlaps the through hole; and
and a metal part configured to fill the through hole,
The metal part protrudes toward the semiconductor light emitting device from the entrance of the through hole. delete According to claim 1,
The metal part passes through the hollow part through the protrusion and is connected to the conductive electrode of the semiconductor light emitting device. delete According to claim 1,
The metal part comprises a first metal material applied to the inner wall of the through hole, and a second metal material plated on the first metal material to fill the through hole. 6. The method of claim 5,
wherein the first metal material includes a first portion covering the conductive electrode of the semiconductor light emitting device, and a second portion formed in a direction perpendicular to the first portion and formed on an inner wall of the through hole. display device. delete According to claim 1,
A reflective layer is formed on one surface of the base body. 9. The method of claim 8,
A reflective through-hole corresponding to the through-hole is formed in the reflective layer, and the metal part fills the reflective through-hole. 9. The method of claim 8,
A metal layer is formed on the reflective layer along an outer periphery of the through hole, and the solder is laminated on the metal layer. According to claim 1,
The semiconductor light emitting device,
a conductive semiconductor layer;
a conductive electrode formed on one surface of the conductive semiconductor layer; and
and a passivation layer surrounding at least a portion of the semiconductor light emitting device,
The through hole is a display device, characterized in that made of a smaller size than the conductive electrode. 12. The method of claim 11,
The conductive electrode comprises a first annular region in contact with the solder, and a second region in contact with the metal portion and formed inside the first region. delete delete delete

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