KR102205693B1 - 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. A display device according to the present invention includes a substrate including a plurality of metal pads, and a plurality of semiconductor light emitting devices electrically connected to the metal pads through self-assembly. Each of the semiconductor light emitting devices includes a conductive type semiconductor layer, a conductive type electrode formed on one surface of the conductive type semiconductor layer, and a passivation layer surrounding the semiconductor light emitting device and having a through hole so that the conductive type electrode is exposed. Including, one end of the semiconductor light emitting device is divided into a first portion exposed to the conductive electrode and a second portion exposed to the passivation layer, the maximum width of the metal pad is the width of the second portion to the It is characterized in that it is set in a range of twice the width.

Description

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

The present invention relates to a display device and a method of manufacturing the same, and more particularly, to a flexible display device using a semiconductor light emitting device.

In recent years, in the field of display technology, a display device having excellent characteristics such as thin and flexible has been developed. In contrast, major displays currently commercially available are represented by LCD (Liguid Crystal Display) and AMOLED (Active Matrix Organic Light Emitting Diodes).

However, in the case of LCD, there is a problem that the reaction time is not fast and it is difficult to implement the flexible, and in the case of AMOLED, there is a vulnerability that the lifespan is short, the mass production yield is not good, and the degree of flexibility is weak.

On the other hand, Light Emitting Diode (LED) is a well-known semiconductor light-emitting device that converts current into light. Starting with the commercialization of red LEDs using GaAsP compound semiconductors in 1962, information along with GaP:N series green LEDs It has been used as a light source for display images in electronic devices including communication devices. Accordingly, a method for solving the above problem may be proposed by implementing a flexible display using the semiconductor light emitting device.

However, in the case of a flexible display using a semiconductor light emitting device, it is difficult to implement a large-screen display device. Therefore, in recent years, a manufacturing method in which a semiconductor light emitting device is bonded to a substrate by self-assembly has been developed. In this case, defects may occur during assembly of the semiconductor light emitting device, and thus, in the present invention, a mechanism capable of reducing such defects is proposed.

An object of the present invention is to provide a structure for improving the reliability of assembly when self-assembling a semiconductor light emitting device in a display device.

Another object of the present invention is to provide a display device that can be assembled one-to-one with a self-assembled region and a semiconductor light emitting device.

A display device according to the present invention includes a substrate including a plurality of metal pads, and a plurality of semiconductor light emitting devices electrically connected to the metal pads through self-assembly. Each of the semiconductor light emitting devices includes a conductive type semiconductor layer, a conductive type electrode formed on one surface of the conductive type semiconductor layer, and a passivation layer surrounding the semiconductor light emitting device and having a through hole so that the conductive type electrode is exposed. Includes. One end of the semiconductor light emitting devices is divided into a first portion to which the conductive electrode is exposed and a second portion to which the passivation layer is exposed, and a maximum width of the metal pad is a width of the second portion to twice the width It can be set in the range of.

In an embodiment, the passivation layer includes a side portion covering a side surface of the semiconductor light emitting device and an extension portion extending from the side portion to cover the one end portion, and a width of the second portion may be a minimum width of the extension portion.

The width of the second portion may be a distance between an outer circumference and an inner circumference of the extension portion or a distance from a portion protruding through the through hole of the conductive electrode to the side portion.

In an embodiment, the substrate includes a lower wiring made of a conductive material and an insulating layer covering the lower wiring, and the metal pads are connected to the lower wiring and penetrated through the insulating layer to be exposed to the outside. Is placed.

In an embodiment, the maximum width of the metal pad may be a diameter or a diagonal distance of a portion where the metal pad is exposed to the outside. A portion of the metal pad exposed to the outside may have a shape in which the one end portion is reduced to 25 to 75%. The first portion may be formed in the same shape as a portion where the metal pad is exposed to the outside.

In an embodiment, a portion of the metal pad exposed to the outside may be disposed at the center of the one end.

In the display device according to the present invention, since the minimum distance (X) of the area without the conductive electrode of the semiconductor light emitting device (X) ≤ the maximum distance of the metal pad of the substrate (Y) ≤ 2X, one self-assembled area Only semiconductor light emitting devices can be assembled. Through this, it is possible to secure a production yield by improving assembly reliability in the self-assembly process.

In addition, through this, when a plurality of semiconductor light emitting devices are coupled to one metal pad, a mechanism in which electrical connection between the conductive electrode and the conductive pad is not possible may be implemented.

1 is a conceptual diagram showing an embodiment of a display device using a semiconductor light emitting device of the present invention.
2 is a partially enlarged view of portion 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 diagrams illustrating various forms of implementing colors in relation to a flip chip type semiconductor light emitting device.
6 is a cross-sectional view showing a method of manufacturing a display device using the semiconductor light emitting device of the present invention.
7 is a perspective view showing another embodiment of a display device using the semiconductor light emitting device of the present invention.
8 is a cross-sectional view taken along the 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 having a new structure and a wiring board are applied.
11 is a cross-sectional view taken along the line EE of FIG. 10.
12A and 12B are plan views of the semiconductor light emitting device and wiring board of FIG. 10, and FIG. 13 is an enlarged view illustrating the semiconductor light emitting device of the new structure of FIG. 10.
14 is a cross-sectional view of a portion corresponding to line EE of FIG. 10 in a display device according to another exemplary embodiment of the present invention, and FIG. 15 is a conceptual diagram illustrating a flip chip type semiconductor light emitting device of FIG. 14.
16A and 16B, 17A, 17B, and 18 are plan views of a semiconductor light emitting device and a wiring board in display devices according to another exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but identical or similar elements are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used interchangeably in consideration of only the ease of preparation of the specification, and do not have meanings or roles that are distinguished from each other by themselves. In addition, in describing the embodiments disclosed in the present specification, when it is determined that a detailed description of related known technologies may obscure the subject matter of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are for easy understanding of the embodiments disclosed in the present specification and should not be construed as limiting the technical idea disclosed in the present specification by the accompanying drawings.

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

Display devices described herein include 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, etc. However, it will be readily apparent to those skilled in the art that the configuration according to the embodiment described in the present specification may be applied to a display capable device even in a new product type to be developed later.

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

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

Flexible displays include displays that can be bent, bent, twistable, foldable, and rollable by external force. For example, the flexible display may be a display manufactured on a thin and flexible substrate that can be bent, bent, foldable 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 (for example, 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 that is 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 a curved surface. This visual information is implemented by independently controlling light emission of sub-pixels arranged in a matrix form. The unit pixel means a minimum unit for implementing 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 illustrated as a kind of semiconductor light emitting device that converts current into light. The light emitting diode is formed in a small size, and through this, 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.

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

2, 3A and 3B, a display device 100 using a passive matrix (PM) type semiconductor light emitting device is illustrated as a display device 100 using a semiconductor light emitting device. However, the example described below is 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) and polyethylene terephthalate (PET) may be used as long as it has insulation and is flexible. In addition, the substrate 110 may be a transparent material or an opaque material.

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

As illustrated, the insulating layer 160 may be disposed on the substrate 110 on which the first electrode 120 is located, and the auxiliary electrode 170 may be disposed on the insulating layer 160. In this case, a state in which the insulating layer 160 is stacked 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), PET, and PEN, and may be formed integrally 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, and is positioned on the insulating layer 160 and is disposed corresponding to the position of the first electrode 120. For example, the auxiliary electrode 170 has a dot shape and may be electrically connected to the first electrode 120 through an electrode hole 171 penetrating through the insulating layer 160. The electrode hole 171 may be formed by filling a via hole with a conductive material.

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

As such an 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 allows electrical interconnection in the Z direction passing through the thickness, but may be configured as a layer having electrical insulation in the horizontal X-Y direction. Therefore, the conductive adhesive layer 130 may be referred to as a Z-axis conductive layer (however, 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 becomes conductive 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 partially have conductivity. This method may be, for example, only one of the above heat and pressure is applied or UV curing or the like.

In addition, the anisotropic conductive medium may be, for example, conductive balls or conductive particles. As shown in the drawing, 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 becomes conductive by the conductive balls. In the anisotropic conductive film, a core of a conductive material may contain a plurality of particles covered by an insulating film made of a polymer material, and in this case, a portion to which heat and pressure is applied is destroyed by the insulating film and becomes conductive by the core. . 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 to the anisotropic conductive film as a whole, and an electrical connection in the Z-axis direction is partially formed due to a height difference of a counterpart adhered by the anisotropic conductive film.

As another example, the anisotropic conductive film may contain a plurality of particles coated with a conductive material in an insulating core. In this case, the part to which heat and pressure are applied is deformed (pressed together) to have 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 and has conductivity in the thickness direction of the film is also possible. In this case, the conductive material may have a pointed end.

As illustrated, the anisotropic conductive film may be a fixed array anisotropic conductive film (ACF) in which conductive balls are inserted into one surface of an insulating base member. More specifically, the insulating base member is formed of an adhesive material, and the conductive ball is 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 ball. Accordingly, 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 consists of a plurality of layers, and a form in which conductive balls are disposed in one layer (double- ACF) etc. are all possible.

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

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

After forming the conductive adhesive layer 130 with the auxiliary electrode 170 and the second electrode 140 positioned on the insulating layer 160, the semiconductor light emitting device 150 is connected in a flip chip form by applying heat and pressure. Then, 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, and an active layer ( And an n-type semiconductor layer 153 formed on 154) and an n-type electrode 152 disposed horizontally apart from the p-type electrode 156 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 may be electrically connected to the plurality of semiconductor light emitting devices 150. For example, p-type electrodes of the left and right semiconductor light emitting devices with the auxiliary electrode at the center may be electrically connected to one auxiliary electrode.

More specifically, the semiconductor light emitting device 150 is pressed 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 the remaining portion does not have conductivity because there is no press-fitting of the semiconductor light emitting device. In this way, the conductive adhesive layer 130 not only mutually couples 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 a phosphor layer 180 is formed in the light emitting device array.

The light emitting device array may include a plurality of semiconductor light emitting devices having different self-luminance values. Each semiconductor light emitting device 150 constitutes a unit pixel and is electrically connected to the first electrode 120. For example, the first electrode 120 may be plural, the semiconductor light emitting elements are arranged in rows, for example, and the semiconductor light emitting elements of each row 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. Further, 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 with a small size.

As illustrated, a partition wall 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, when the semiconductor light emitting device 150 is inserted 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 partition wall 190 may have reflective properties and increase contrast even without a separate black insulator.

As another example, a reflective partition wall may be separately provided as the partition wall 190. In this case, the partition wall 190 may include a black or white insulator depending on the purpose of the display device. When a partition wall of a white insulator is used, it is possible to increase reflectivity, and when a partition wall of a black insulator is used, it is possible to increase the contrast while having reflective characteristics.

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 emitting 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 individual pixels.

That is, at a position forming a red unit pixel, a red phosphor 181 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 151, and a position forming the green unit pixel 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. Also, only the blue semiconductor light emitting device 151 may be used alone in a 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 of the first electrode 120 may be an electrode that controls one color. That is, along the second electrode 140, red (R), green (G), and blue (B) may be sequentially disposed, and a unit pixel may be implemented through this.

However, the present invention is not necessarily limited thereto, and unit pixels of red (R), green (G), and blue (B) can be implemented by combining the semiconductor light emitting device 150 and the quantum dot (QD) instead of the phosphor. have.

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

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. 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, B) are alternately arranged, and unit pixels of red, green, and blue by red, green, and blue semiconductor light emitting devices They form one pixel, through which a full color display can be implemented.

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 individual device. In this case, in order to form a unit pixel, 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. In addition, a unit pixel may be formed by using a color filter in which red, green, and blue are repeated on the white light emitting device W.

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 not only for visible light but also for ultraviolet (UV) light, and the ultraviolet (UV) can be extended in the form of a semiconductor light emitting device that can be used as an excitation source of the upper phosphor. .

Looking again at 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 with a small size. 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 rectangle, the size may be 20X80㎛ or less.

In addition, even when the 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 is exhibited. Accordingly, for example, when the size of 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 elements is relatively large enough. Therefore, 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 showing a method of manufacturing a display device using the semiconductor light emitting device of the present invention.

Referring to this drawing, 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 stacked on the first substrate 110 to form one substrate (or wiring board), and the first electrode 120, the auxiliary electrode 170, and the second electrode 140 are formed on the wiring board. 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, an anisotropic conductive film may be applied to a substrate on which the insulating layer 160 is positioned.

Next, the second substrate 112 corresponding to the positions of the auxiliary electrodes 170 and the second electrodes 140 and on which the plurality of semiconductor light emitting elements 150 constituting individual pixels are positioned is formed. ) 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 spire substrate or a silicon substrate.

When the semiconductor light emitting device is formed in units of a wafer, it can be effectively used in a display device by having a gap and a size capable of forming a display device.

Then, the wiring board and the second board 112 are thermally compressed. For example, the wiring board and the second board 112 may be thermocompressed by applying an ACF press head. The wiring board and the second board 112 are bonded by the thermal compression bonding. Due to the property of the anisotropic conductive film having conductivity by thermocompression bonding, only the portion between the semiconductor light emitting device 150 and the auxiliary electrode 170 and the second electrode 140 has conductivity, through which electrodes and semiconductor light emission The device 150 may be electrically connected. In this case, the semiconductor light emitting device 150 is inserted into the anisotropic conductive film, and a partition wall may be formed between the semiconductor light emitting devices 150 through this.

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

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 bonded.

In addition, a step of forming a phosphor layer on one surface of the semiconductor light emitting device 150 may be further included. 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 used to emit the blue semiconductor light. A layer can be formed on one side of the device.

The manufacturing method or structure of a 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 modified examples or embodiments described below, the same or similar reference numerals are assigned to the same or similar configurations as the previous 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 DD of FIG. 7, and FIG. 9 is a conceptual diagram showing the vertical semiconductor light emitting device of FIG. 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 board 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 insulation and is flexible may be used.

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

The conductive adhesive layer 230 is formed on the substrate 210 on which the first electrode 220 is located. Like a display device to which a flip chip type light emitting element is applied, the conductive adhesive layer 230 is a solution containing an anisotropic conductive film (ACF), an anisotropic conductive paste, and conductive particles. ), etc. However, also in this embodiment, the case in which the conductive adhesive layer 230 is implemented by the anisotropic conductive film is illustrated.

After the anisotropic conductive film is positioned on the substrate 210 with the first electrode 220 positioned, the semiconductor light emitting element 250 is connected by applying heat and pressure to the semiconductor light emitting element 250. It is electrically connected to the electrode 220. In this case, the semiconductor light emitting device 250 is preferably disposed to be positioned on the first electrode 220.

As described above, the electrical connection is created because the anisotropic conductive film partially has conductivity in the thickness direction when heat and pressure are applied. Accordingly, the anisotropic conductive film is divided into a portion 231 having conductivity and a portion 232 having no conductivity in the thickness direction.

In addition, since the anisotropic conductive film contains an adhesive component, the conductive adhesive layer 230 implements electrical connection as well as mechanical coupling between the semiconductor light emitting device 250 and the first electrode 220.

In this way, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230, thereby configuring individual pixels in the display device. Since the semiconductor light emitting device 250 has excellent luminance, individual unit pixels can be configured with a small size. The 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 rectangle, the size may be 20X80㎛ or less.

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

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

Referring to FIG. 9, such a 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 p-type electrode 256 located at the bottom may be electrically connected by the first electrode 220 and the conductive adhesive layer 230, and the n-type electrode 252 located at the top is a second electrode 240 to be described later. ) And can be electrically connected. The vertical semiconductor light emitting device 250 has a great advantage of reducing a chip size since 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 a 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, at a position forming a red unit pixel, a red phosphor 281 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 251, and a position forming the green unit pixel 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 a 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 other structures for implementing blue, red, and green colors may be applied as described above in a display device to which a flip chip type light emitting device is 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 rows, and the second electrode 240 may be located between the rows 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 long bar-shaped electrode in one direction, and may be disposed in a direction perpendicular to the first electrode.

In addition, the second electrode 240 and the semiconductor light emitting device 250 may be electrically connected 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 vapor 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) or the like 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 ITO (Indium Tin Oxide) is used to place the second electrode 240 on the semiconductor light emitting device 250, the ITO material has poor adhesion to the n-type semiconductor layer. have. Accordingly, according to the present invention, by placing the second electrode 240 between the semiconductor light emitting devices 250, there is an advantage in that a transparent electrode such as ITO is not required. Accordingly, the light extraction efficiency can be improved by using the n-type semiconductor layer and a conductive material having good adhesion as a horizontal electrode without being restricted by the selection of a transparent material.

As illustrated, a partition wall 290 may be positioned between the semiconductor light emitting devices 250. That is, a partition wall 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, if the base member of the anisotropic conductive film is black, the partition wall 290 may have reflective properties and a contrast ratio may be increased even without a separate black insulator.

As another example, as the partition wall 190, a reflective partition wall may be separately provided. The partition wall 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 elements 250, the partition wall 290 is between the vertical semiconductor light emitting element 250 and the second electrode 240. It can be located between. Accordingly, individual unit pixels can be configured with a small size using the semiconductor light emitting device 250, and the distance between the semiconductor light emitting device 250 is relatively large enough, so that the second electrode 240 is connected to the semiconductor light emitting device 250. ), there is an effect of implementing a flexible display device having HD image quality.

Further, according to the illustration, a black matrix 291 may be disposed between each phosphor to improve contrast. That is, the black matrix 291 can improve contrast of light and dark.

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

In the display device using the semiconductor light emitting device of the present invention described above, a semiconductor light emitting device grown on a wafer and formed through mesa and isolation is used as individual pixels. Since a semiconductor light emitting device grown on a wafer is transferred 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 into a wiring board in a self-assembly method may be applied.

In the self-assembly method, 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 placed in a chamber filled with a fluid, and the fluid is heated so that the semiconductor light emitting devices are self-assembled to the substrate. To this end, grooves into which the semiconductor light emitting devices are inserted may be provided in the substrate. Specifically, grooves in which the semiconductor light emitting devices are mounted are formed in the substrate at a position where the semiconductor light emitting devices are aligned with the wiring electrode. The grooves are formed in a shape corresponding to the shape of the semiconductor light emitting devices, and the semiconductor light emitting devices move randomly in the fluid and then are assembled into the grooves.

Meanwhile, in this self-assembly method, defects may occur during assembly of the semiconductor light emitting device, and the present invention proposes a semiconductor light emitting device and a wiring board having a new structure capable of reducing such defects. Hereinafter, this will be described in more detail with reference to the drawings.

FIG. 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 and a wiring board of a new structure are applied, and FIG. 11 is a cross-sectional view taken along the line EE of FIG. 10, and FIG. 12A And FIG. 12B is a plan view of the semiconductor light emitting device and the wiring board of FIG. 10, and FIG. 13 is an enlarged view illustrating the semiconductor light emitting device of the new structure of FIG. 10.

10, 11, 12A, 12B, and 13, as a display device 1000 using a semiconductor light emitting device, a display device using a vertical semiconductor light emitting device of a passive matrix (PM) method ( 1000) is illustrated. However, the example described below is applicable to an active matrix (AM) type semiconductor light emitting device.

The display device 1000 includes a substrate 1010, a first electrode 1020, a second electrode 1040, a plurality of semiconductor light emitting devices 1050, an insulating layer 1060, and metal pads 1070. Here, the first electrode 1020 and the second electrode 1040 may each include a plurality of electrode lines.

The substrate 1010 is a wiring board 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 insulation and is flexible may be used.

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

As illustrated, the insulating layer 1060 may be disposed on the substrate 1010 on which the first electrode 1020 is located, and the metal pads 1070 may be disposed on the insulating layer 1060. More specifically, the first electrode 1020 may be disposed on one surface of the substrate 1010, and an insulating layer 1060 covering the first electrode 1020 may be formed on the one surface. In this case, a state in which the insulating layer 1060 is stacked on the substrate 1010 may be a single wiring board. In addition, the first electrode 1020 may be a lower wiring made of a conductive material.

More specifically, the insulating layer 1060 is made of an insulating and flexible material such as polyimide (PI), PET, and PEN, and is formed integrally with the substrate 1010 while covering the lower wiring. A wiring board can be formed.

The metal pads 1070 are auxiliary electrodes that electrically connect the first electrode 120 and the semiconductor light emitting device 1050, and are positioned on the insulating layer 1060 and are disposed to correspond to the positions of the first electrode 1020 do. For example, the metal pads 1070 have a dot shape and may be electrically connected to the first electrode 1020 through an electrode hole 1071 penetrating the insulating layer 1060. That is, the metal pads 1070 may be connected to the lower wiring and disposed to penetrate the insulating layer 1060 to be exposed to the outside.

As illustrated, the semiconductor light emitting device 1050 has a shape fitted to the metal pads 1070.

Referring to FIG. 13, for example, the semiconductor light emitting device 1050 includes a first conductive type electrode 1156, a first conductive type semiconductor layer 1155 on which the first conductive type electrode 1156 is formed, The active layer 1154 formed on the first conductive type semiconductor layer 1155, the second conductive type semiconductor layer 1153 formed on the active layer 1154, and a second conductive type semiconductor layer 1153 formed on the second conductive type semiconductor layer 1153 And a conductive type electrode 1152.

The first conductive type semiconductor layer 1155 and the second conductive type semiconductor layer 1153 overlap each other, and a second conductive type electrode 1152 is disposed on an upper surface of the second conductive type semiconductor layer 1153, and the A first conductive type electrode 1156 is disposed on the lower surface of the first conductive type semiconductor layer 1155. In this case, the top surface of the second conductive type semiconductor layer 1153 is one surface of the second conductive type semiconductor layer 1153 furthest from the first conductive type semiconductor layer 1155, and the first conductive type semiconductor layer ( The lower surface of 1155 may be one surface of the first conductive type semiconductor layer 1155 farthest from the second conductive type semiconductor layer 1153. In this way, the first conductive type electrode 1156 and the second conductive type electrode 1152 are respectively upper and lower with the first conductive type semiconductor layer 1155 and the second conductive type semiconductor layer 1153 interposed therebetween. Is placed.

Referring to FIG. 13 together with FIGS. 10, 11, 12A, and 12B, the lower surface of the first conductive type semiconductor layer 1155 may be a surface closest to the wiring board, and the second conductive type The upper surface of the semiconductor layer may be a surface farthest from the wiring board.

More specifically, the first conductive type electrode 1156 and the first conductive type semiconductor layer 1155 may be a p-type electrode and a p-type semiconductor layer, respectively, and the second conductive type electrode 1152 and the second The conductivity-type 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 an example in which the first conductivity type is n-type and the second conductivity type is p-type is also possible.

In this case, the p-type electrode located at the top may be electrically connected to the first electrode 1020 and the conductive adhesive layer 1030, and the n-type electrode located at the bottom 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.

As another example, the n-type electrode and the second electrode 1040 may be integrally formed. That is, when the second conductive type electrode 1152 is deposited on one surface of the second conductive type semiconductor layer 1153, it is formed in the same line shape as the second electrode to electrically connect neighboring semiconductor light emitting devices. .

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

The passivation layer 1160 surrounds a 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 conductive semiconductor layer 1155 and the second conductive semiconductor layer 1153 are electrically disconnected by the passivation layer 1160, the P-type GaN and N of the semiconductor light emitting device are -type GaN can be insulated from each other.

Meanwhile, referring to FIGS. 10 to 12B, a plurality of semiconductor light emitting devices are disposed in a direction crossing the length direction of the first electrode 1020 and electrically connected to the semiconductor light emitting device 1050. The two electrodes 1040 are located.

As illustrated, the second electrode 1040 may be positioned on the flat layer 1030. The planarization layer 1030 is disposed between the insulating layer 1060 of the wiring board and the second electrode 1040. More specifically, an insulating material is filled between the semiconductor light emitting devices to form a flat layer, and a second electrode 1040 serving as an upper wiring is disposed on one surface of the flat layer 1030. In this case, the second electrode 1040 may be electrically connected by contact with the second conductive type electrode 1152 of the semiconductor light emitting device 1050.

According to the structure described above, the plurality of semiconductor light emitting devices 1050 are coupled to the wiring board 1010 and are electrically connected to the first electrode 1020 and the second electrode 1040.

As illustrated, a 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 device 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 emitting blue (B) light, and the phosphor layer 1080 performs a function of converting 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, at a position forming a red unit pixel, a red phosphor 1081 capable of converting blue light into red (R) light may be stacked on the blue semiconductor light emitting device 1051a, and a position forming the green unit pixel In, a green phosphor 1082 capable of converting blue light to green (G) light may be stacked on the blue semiconductor light emitting device 1051b. Also, only the blue semiconductor light emitting device 1051c may be used alone in a 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 that controls one color. That is, along the second electrode 1040, red (R), green (G), and blue (B) may be sequentially disposed, and a unit pixel may be implemented through this. However, the present invention is not necessarily limited thereto, and a unit pixel that emits red (R), green (G) and blue (B) by combining the semiconductor light emitting device 1050 and the quantum dot (QD) instead of the phosphor Can be implemented.

Meanwhile, in order to improve the contrast of the phosphor layer 1080, the display device may further include a black matrix 1091 disposed between the phosphors. The black matrix 1091 may be formed in such a manner that a gap is formed between phosphor dots and a black material fills the gap. Through this, the black matrix 1091 may absorb external light reflection and improve contrast of contrast. 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, the phosphor layer is not formed at the position corresponding to the blue semiconductor light emitting device 1051, but the black matrix 1091 has a space without the phosphor layer therebetween (or the blue semiconductor light emitting device 1051c). Put on) can be formed on both sides respectively.

A display device including a semiconductor light emitting device may be implemented by self-assembly by the structure described above.

In this case, the passivation layer 1160 includes a through hole 1161 so that the first conductive electrode 1156 is exposed. The metal pad 1070 is inserted into the through hole 1161, through which the semiconductor light emitting device may be coupled to the wiring board. In this case, the metal pad 1070 may include an alloy made of a combination of at least two or more of Bi, In, Pb, Sn, and Ag. At this time, when the semiconductor light emitting device is self-assembled, the wiring board is immersed in the fluid while the metal pad 1070 is melted, and the metal pad 1070 and the metal pad 1070 are solidified while the metal pad 1070 is solidified. Conductive electrodes are coupled to each other.

The semiconductor light emitting device and the metal pad of the present example have a mechanism capable of securing assembly reliability during self-assembly.

For example, one end of the semiconductor light emitting devices may be divided into a first part 1055 to which the conductive electrode is exposed and a second part 1056 to which the passivation layer 1160 is exposed. In this example, the one end portion corresponds to a lower surface of the semiconductor light emitting devices, and may be a surface closest to the wiring board and a peripheral portion thereof.

As shown in the drawing, since the first conductive electrode 1156 is exposed by the through hole 1161 of the passivation layer 1160, the first part 1055 is a part corresponding to the through hole 1161 Can be The second portion 1056 is a region from the outer periphery of the through hole 1161 to the outer periphery of the passivation layer 1160 on the lower surfaces of the semiconductor light emitting devices, and the first conductive electrode 1156 at the one end This can be an unexposed area.

In this case, the maximum width (Y) of the metal pad 1070 is between the width (X) and the width of the second portion so as to limit contact of a plurality of conductive-type electrodes with one of the metal pads 1070. It can be set in a double range. More specifically, the width of the second portion 1056 may be the minimum distance of a region of the semiconductor light emitting device without a conductive electrode. Accordingly, X and Y are set in the range of X ≤ Y ≤ 2X, and through this, only one semiconductor light emitting device can be assembled in one self-assembled area.

In this case, the minimum distance (X) of the area without the metal pad in the semiconductor light emitting device is the minimum distance of the portion covered by the passivation layer 1160 from the end of the light emitting device when the passivation layer 1160 is formed over the conductive electrode. Can be.

As a more specific example, the passivation layer 1160 includes a side portion 1162 covering a side surface of the semiconductor light emitting device and an extension portion 1163 extending from the side portion 1162 to cover the one end, and the second portion The width of 1055 may be the minimum width of the extension part 1163. At this time, the extension portion 1163 is formed in a hollow shape and has an outer periphery and an inner periphery, and the width of the second portion 1056 is a distance between the outer periphery and the inner periphery.

As an example, the size of the semiconductor light emitting device is made of a size smaller than 100 micrometers X 100 micrometers, and the shape is circular, triangular, square and It can be a polygonal shape.

In this embodiment, a circular conductive electrode is presented. As illustrated, a portion of the metal pad 1070 exposed to the outside may be disposed at the center of the one end. For example, when the second portion 1056 has a shape of a hollow park as in this example, the one end portion and the first portion 1055 may be formed in a circular shape. In this case, a portion of the metal pad 1070 exposed to the outside may have a shape in which the one end portion is reduced to 25 to 75%.

Accordingly, the first portion 1055 has the same shape as the portion where the metal pad 1070 is exposed to the outside. In conclusion, a portion of the metal pad 1070 exposed to the outside may be circular, and a maximum width of the metal pad 1070 may be a diameter of a portion exposed to the outside of the metal pad 1070.

As shown in FIGS. 12A and 12B, since the maximum width of the metal pad 1070 is less than or equal to twice that of the second portion 1056, when two semiconductor light emitting devices cover the metal pad 1070 Only the second part 1056 comes into contact with the metal pad 1070.

Therefore, it may be limited that the conductive electrodes of the two semiconductor light emitting devices contact one metal pad. That is, when the diameter of the circular metal pad 1070 is a structure in which two second portions 1056, which are hollow cones, overlap, all of them are covered, so that two electrical connections cannot be made to one metal pad.

As described above, in the display device according to the present exemplary embodiment, when assembling the semiconductor light emitting device to the substrate in a self-assembled manner, only one semiconductor light emitting device may be assembled in one self-assembled region.

Meanwhile, the display device using the semiconductor light emitting device described above may be modified in various forms. Hereinafter, such modified examples will be described.

14 is a cross-sectional view of a portion corresponding to line E-E of FIG. 10 in a display device according to another exemplary embodiment of the present invention, and FIG. 15 is a conceptual diagram illustrating the flip chip type semiconductor light emitting device of FIG. 14.

As illustrated, a display device 2000 using a passive matrix (PM) type vertical semiconductor light emitting device is illustrated as a display device 2000 using a semiconductor light emitting device. However, this example can be applied to an active matrix (AM) type semiconductor light emitting device.

In this example described below, the same or similar reference numerals are assigned to each of the configurations of the examples described with reference to FIGS. 10 to 13 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 flat layer 2030, a second electrode 2040, a plurality of semiconductor light emitting devices 2050, an insulating layer 2060, and Metal pads 2070 are included, and a description thereof will be replaced with a description with reference to FIGS. 10 to 13 above. In addition, the display device of the present exemplary embodiment may include a phosphor layer 2080 or a black matrix 2091, and descriptions thereof will be replaced with descriptions with reference to FIGS. 10 to 13.

Referring to the drawings, for example, the semiconductor light emitting device 2050 includes a first conductive type electrode 2156, a first conductive type semiconductor layer 2155 on which the first conductive type electrode 2156 is formed, An active layer 2154 formed on the first conductive type semiconductor layer 2155, a second conductive type semiconductor layer 2153 formed on the active layer 2154, and a second conductive type semiconductor layer 2153 formed on the second conductive type semiconductor layer 2153. And a conductive type electrode 2152. In addition, the semiconductor light emitting device may include a passivation layer 2160. In this case, except for the first conductive type electrode 2156 and the passivation layer 2160, the first conductive type semiconductor layer 2155, the active layer 2154, the second conductive type semiconductor layer 2153, and the The two-conductive electrode 2152 may have the same structure as the above-described example, and a description thereof will be replaced with a description of the example with reference to FIGS.

Meanwhile, the semiconductor light emitting device includes a passivation layer 2160 formed to surround side surfaces of the first conductive type semiconductor layer 2155 and the second conductive type semiconductor layer 2153. The passivation layer 2160 covers a side surface of the semiconductor light emitting device to stabilize characteristics of the semiconductor light emitting device, and is formed of an insulating material.

In this case, the passivation layer 2160 includes a through hole 2161 so that the first conductive electrode 2156 is exposed. The first conductive electrode 2156 passes through the through hole 2161 and protrudes to be exposed to the outside. In this case, the first conductive electrode 2156 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.

For example, one end of the semiconductor light emitting devices may be divided into a first portion 2055 to which the conductive electrode 2156 is exposed and a second portion 2056 to which the passivation layer 2160 is exposed. In this example, the one end portion corresponds to a lower surface of the semiconductor light emitting devices, and may be a surface closest to the wiring board and a peripheral portion thereof.

As shown in the drawing, since the first conductive type electrode 2161 is derived by the through hole 2161 of the passivation layer 2160, the first part 2055 is formed of the first conductive type electrode 2161. It can be the part that corresponds to the bottom. In addition, the second portion 2055 is a region from the end of the first conductive type electrode 2161 to the outer circumference of the passivation layer 2160, and is formed by the first conductive type electrode 2161 at the one end. It can be an uncovered area.

The maximum width (Y) of the metal pad 2070 is in the range of 2 times the width (X) of the second portion 2056 to limit contact of a plurality of conductive electrodes with one of the metal pads. Can be set in In this case, the width of the second portion 2056 may be the shortest distance from the end of the first conductive electrode 2161 to the outer periphery of the passivation layer 2160.

As a more specific example, the passivation layer 2160 includes a side portion 2162 covering a side surface of the semiconductor light emitting device and an extension portion 2163 extending from the side portion 2162 to cover the one end, and the second portion The minimum width of 2056 may be the minimum width of the exposed portion of the extension part 2163. In this case, the width of the second portion 2056 may be a distance from the protruding portion of the conductive electrode from the extension portion 2163 to the side portion 2162.

Also in this example, X and Y are set in the range of X ≤ Y ≤ 2X, and through this, the condition that only one semiconductor light emitting device is assembled in one self-assembled region is satisfied.

On the other hand, the shape of the conductive electrode or metal pads of the present invention can be modified in various forms. Hereinafter, such a modified example will be described with reference to the drawings.

16A and 16B, 17A, 17B, and 18 are plan views of a semiconductor light emitting device and a wiring board in display devices according to still another embodiment of the present invention.

In the embodiment with reference to FIGS. 16A and 16B, a rectangular conductive electrode is presented. As illustrated, a portion of the metal pad exposed to the outside may be disposed at the center of one end of the semiconductor light emitting device. In addition, a portion of the metal pad exposed to the outside may have a shape in which the one end portion is reduced to 25 to 75%. As in this example, when the second portion 3056 of the one end has a shape of a hollow square, the one end and the first portion 3055 may be formed in a square shape. In this case, the maximum width of the metal pad may be a diagonal distance of a portion where the metal pad is exposed to the outside.

Therefore, in this example, the diagonal distance of the portion where the metal pad is exposed to the outside is the maximum width (Y) of the metal pad, and is set in the range of the width (X) of the second portion 3056 to twice the width. Can be.

As another example, in the embodiment with reference to FIGS. 17A and 17B, a triangular conductive electrode is presented. As in this example, when the second portion 4056 of the one end has a hollow triangle shape, the one end and the first portion 4055 may be formed in a triangle. In this case, the maximum width of the metal pad may be a distance of one side of a portion where the metal pad is exposed to the outside.

Therefore, in this example, the distance of one side of the portion where the metal pad is exposed to the outside is the maximum width (Y) of the metal pad, and the width (X) of the second portion 4056 of the semiconductor light emitting device is 2 to 2 Can be set in the ship's range.

As another example, as shown in FIG. 18, the lower end of the semiconductor light emitting device is made of any one of a circle, an equilateral triangle, a square, a rectangle, and an ellipse, and the conductive electrode may be formed of any one of a circle, an equilateral triangle, a square, a rectangle and an ellipse Do. A portion of the metal pad exposed to the outside has a shape corresponding to the conductive electrode. In this case, the width X of the second portion of the semiconductor light emitting device may be a minimum distance among distances between the conductive electrode and the outer periphery of the lower end of the semiconductor light emitting device.

As described above, the assembly area of the wiring board corresponding to the lower end of the semiconductor light emitting device has the same shape as the area where the conductive electrode of the semiconductor light emitting device is exposed, and its size is set as X ≤ Y ≤ 2X, so that one self-assembly. Only one semiconductor light emitting device can be assembled in the region. Through this, when a plurality of semiconductor light emitting devices are coupled to one metal pad, a mechanism in which electrical connection between the conductive electrode and the conductive pad is not possible may be implemented.

The display device using the semiconductor light emitting device described above is not limited to the configuration and method of the above-described embodiments, and the above embodiments are configured by selectively combining all or part of each of the embodiments so that various modifications can be made. May be.

Claims (14)

A substrate having a plurality of metal pads; And
Including a plurality of semiconductor light emitting devices electrically connected to the metal pads through self-assembly,
Each of the semiconductor light emitting devices,
A conductive semiconductor layer;
A conductive type electrode formed on one surface of the conductive type semiconductor layer; And
Comprising a passivation layer surrounding the semiconductor light emitting device and having a through hole so that the conductive electrode is exposed,
One end of the semiconductor light emitting devices is divided into a first portion to which the conductive type electrode is exposed and a second portion to which the passivation layer is exposed,
The display device, characterized in that the maximum width of the metal pad is set within a range of the width of the second portion to twice the width. The method of claim 1,
The passivation layer includes a side portion covering a side surface of the semiconductor light emitting device and an extension portion extending from the side portion to cover the one end portion,
The width of the second portion is a display device, characterized in that the minimum width of the extension portion. The method of claim 2,
The extension portion is formed in a hollow shape and has an outer periphery and an inner periphery, and the width of the second portion is a distance between the outer periphery and the inner periphery. The method of claim 2,
The conductive type electrode protrudes through the through hole, and the width of the second portion is a distance from the protruding portion of the conductive type electrode to the side surface. The method of claim 1,
The substrate,
A lower wiring made of a conductive material; And an insulating layer covering the lower wiring,
The metal pads are connected to the lower wiring and are disposed to penetrate the insulating layer and to be exposed to the outside. The method of claim 5,
The maximum width of the metal pad is,
When the portion of the metal pad exposed to the outside is circular, the diameter of the portion exposed to the outside of the metal pad,
When the part exposed to the outside of the metal pad is a square, the diagonal distance of the part exposed to the outside of the metal pad or
When a portion of the metal pad exposed to the outside is a triangle, the distance of one side of the portion of the metal pad exposed to the outside. The method of claim 6,
The display device, wherein the portion of the metal pad exposed to the outside has a shape in which the one end portion is reduced to 25 to 75%. The method of claim 7,
The first portion is a display device, characterized in that the metal pad is formed in the same shape as a portion exposed to the outside. The method of claim 6,
A display device, wherein a portion of the metal pad exposed to the outside is disposed at the center of the one end. The method of claim 1,
The display device according to claim 1, wherein the metal pad includes an alloy composed of a combination of at least two or more of Bi, In, Pb, Sn, and Ag. The method of claim 10,
The display device, wherein the conductive type electrode includes a plurality of metal layers made of different metals. The method of claim 1,
The semiconductor light emitting device has an n-type electrode and a p-type electrode,
The display device, wherein the conductive type electrode electrically connected to the metal pads is a p-type electrode. The method of claim 12,
An insulating material is filled between the semiconductor light emitting devices to form a flat layer, and an upper wiring electrically connected to the n-type electrode is disposed in the flat layer. The method of claim 1,
The display apparatus according to claim 1, wherein a maximum width of the metal pad is set in a range of a width of the second portion to twice the width of the second portion, and thus a plurality of conductive electrodes are limited in contact with one of the metal pads.

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