KR20190057681A - Display device using semiconductor light emitting device and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a display device and a method of manufacturing the same, and more particularly, to a display device whose brightness is adjusted according to an external light amount. According to the present invention, the display device comprises: a wiring board having a plurality of first electrode lines; a plurality of first semiconductor light emitting elements disposed on the wiring board and electrically connected to one of the first electrode lines; a plurality of second semiconductor light emitting elements emitting light of a wavelength range different from that of the first semiconductor light emitting devices, electrically connected to another one of the first electrode lines and absorbing light to generate a current; and, a transparent electrode line disposed on the second semiconductor light emitting elements so that the current generated from the second semiconductor light emitting elements flows, wherein an amount of light emitted from the second semiconductor light emitting devices varies depending on an amount of the current flowing along the transparent electrode line.

Description

TECHNICAL FIELD [0001] The present invention relates to a display device using a semiconductor light emitting device, and a method of manufacturing the same. [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a method of manufacturing the same, and more particularly, to a display device whose brightness is adjusted according to an external light amount.

In recent years, display devices having excellent characteristics such as a thin shape and a flexible shape in the field of display technology have been developed. On the other hand, major displays that are commercialized today are represented by LCD (Liguid Crystal Display) and AMOLED (Active Matrix Organic Light Emitting Diodes).

However, in the case of an LCD, there is a problem that the reaction time is not fast and the implementation of the flexible is difficult. In the case of the AMOLED, there is a weak point that the life span is short and the mass production yield is not good.

Light emitting diodes (LEDs) are well-known semiconductor light emitting devices that convert current into light. In 1962, red LEDs using GaAsP compound semiconductors were commercialized, Has been used as a light source for a display image of an electronic device including a communication device. Accordingly, a method of solving the above problems by implementing a display using the semiconductor light emitting device can be presented.

On the other hand, attempts to utilize a display using a semiconductor light emitting element in a mobile terminal have continued. The mobile terminal may be used in various environments. Specifically, the mobile terminal can be used not only in an environment where external light is large but also in an environment where there is little external light. For user's convenience, it is necessary to adjust the brightness of the display according to the intensity of external light. In recent years, there is an increasing demand for a user interface that can automatically adjust the display brightness according to external light quantity.

It is an object of the present invention to provide a display device capable of adjusting the brightness of a display according to an external light quantity without using a separate photo-detecting sensor.

A display device according to the present invention includes a wiring board having a plurality of first electrode lines, a plurality of first semiconductor light emitting elements arranged on the wiring board, the plurality of first semiconductor light emitting elements being electrically connected to one of the first electrode lines, A plurality of second semiconductor light emitting devices for emitting light of a different wavelength band from the first semiconductor light emitting devices, electrically connected to the other of the first electrode lines and absorbing light to generate current, And a transparent electrode line disposed on the semiconductor light emitting elements and adapted to allow a current generated from the second semiconductor light emitting elements to flow, wherein an amount of light emitted from the second semiconductor light emitting elements is greater than an amount of the transparent electrode line And varies depending on the amount of current flowing along.

In one embodiment, the second semiconductor light emitting devices may emit light when a voltage is applied between the first electrode line and the transparent electrode line.

In one embodiment, the magnitude of the voltage applied between the first electrode line and the transparent electrode line may vary depending on the amount of current flowing along the transparent electrode line.

In one embodiment, the thickness of the second semiconductor light emitting device may be less than the thickness of the first semiconductor light emitting device.

In one embodiment, the light emitting device may further include a light transmitting layer disposed on the second semiconductor light emitting devices and formed to a height at which the first semiconductor light emitting devices are formed.

In one embodiment, a part of the transparent electrode line may be disposed between the light-transmitting layer and the second semiconductor light-emitting element.

In one embodiment, the semiconductor light emitting device further includes a plurality of second electrode lines electrically connected to the first semiconductor light emitting device on the first semiconductor light emitting device, wherein the second electrode lines and the transparent electrode lines are different from each other Material.

In one embodiment, a portion of the transparent electrode line may be disposed on a different plane than the second electrode line.

In one embodiment, the light emitting device may further include a lens unit disposed to cover the first and second semiconductor light emitting devices.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor light emitting device, comprising: coupling a plurality of first semiconductor light emitting elements to a part of first electrode lines formed on a substrate; And a second semiconductor light emitting element that emits light and generates a current by injecting light into the first semiconductor light emitting element, arranging a transparent electrode line on the second semiconductor light emitting element, Applying a light-transmissive material, etching a portion of each of the light-transmitting material and the first semiconductor light-emitting devices, exposing the portion to the outside, and forming a second electrode line in the portion exposed to the outside The method comprising the steps of:

According to the present invention, in adjusting the brightness of the display device according to the external light amount, a separate sensor for sensing the external light amount is not required.

Further, according to the present invention, since the light emitting element itself generates a signal in accordance with the amount of external light, the external light amount can be accurately reflected to the brightness of the light emitting element.

1 is a conceptual diagram showing an embodiment of a display device using the 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 line BB and CC of Fig.
4 is a conceptual diagram showing a flip chip type semiconductor light emitting device of FIG.
FIGS. 5A to 5C are conceptual diagrams showing various forms of implementing a color 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 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 line DD of FIG.
9 is a conceptual diagram showing a vertical semiconductor light emitting device of FIG.
10 to 12 are sectional views of a display device using the semiconductor light emitting device of the present invention.
13 is a conceptual diagram showing the electrode arrangement of a display device using a semiconductor light emitting element.
14 is a conceptual diagram showing a semiconductor light emitting device having a novel structure.
15A to 15G are cross-sectional views illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.
16A and 16B are conceptual diagrams showing a modification of the display device of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix " module " and " part " for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. In addition, it should be noted that the attached drawings are only 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 attached drawings.

It is also to be understood that when an element such as a layer, region or substrate is referred to as being present on another element "on," it is understood that it may be directly on the other element or there may be an intermediate element 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 device, a slate PC, , A Tablet PC, an Ultra Book, a digital TV, a desktop computer, and the like. However, it will be readily apparent to those skilled in the art that the configuration according to the embodiments described herein may be applied to a device capable of being displayed, even in the form of a new product to be developed in the future.

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

According to the illustrated example, the information processed in the control unit of the display device 100 may be displayed using a flexible display.

The flexible display includes a display that can be bent, twistable, collapsible, and curlable, which can be bent by an external force. For example, a flexible display can be a display made on a thin, flexible substrate that can be bent, bent, folded or rolled like paper while maintaining the display characteristics of conventional flat panel displays.

In a state where 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 is flat. In the first state, the display area may be a curved surface in a state of being bent by an external force (for example, a state having a finite radius of curvature, hereinafter referred to as a second state). As shown in the figure, the information displayed in the second state may be time information output on the curved surface. Such visual information is realized by independently controlling the emission of a sub-pixel 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 exemplified as one type of semiconductor light emitting device for converting a 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 detail with reference to the drawings.

FIG. 2 is a partial enlarged view of a portion A of FIG. 1, FIGS. 3 A and 3B are cross-sectional views taken along lines BB and CC of FIG. 2, FIG. 4 is a conceptual view of a flip chip type semiconductor light emitting device of FIG. FIGS. 5A to 5C are conceptual diagrams showing various forms of implementing a color in relation to a flip chip type semiconductor light emitting device.

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

The display device 100 includes a first 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 first substrate 110 may be a flexible substrate. For example, to implement a flexible display device, the first substrate 110 may include glass or polyimide (PI). In addition, any insulating material such as PEN (polyethylene naphthalate) and PET (polyethylene terephthalate) may be used as long as it is insulating and flexible. In addition, the first substrate 110 may be formed of a transparent material or an opaque material.

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

The insulating layer 160 may be disposed on the first 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 laminated on the first substrate 110 may be a single wiring substrate. More specifically, the insulating layer 160 may be formed of an insulating material such as polyimide (PI), polyimide, PET, or PEN, and may be formed integrally with the first substrate 110, have.

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

Referring to these drawings, the 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 for performing a specific function may be formed between the insulating layer 160 and the conductive adhesive layer 130, or a conductive adhesive layer 130 may be disposed on the first substrate 110 without the insulating layer 160 . In the structure in which the conductive adhesive layer 130 is disposed on the first 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. To this end, the conductive adhesive layer 130 may be mixed with a substance having conductivity and a substance having adhesiveness. Also, the conductive adhesive layer 130 has ductility, thereby enabling the flexible function in the display device.

As 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 may be formed as a layer having electrical insulation in the horizontal X-Y direction while permitting electrical interconnection in the Z direction passing through the thickness. 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. When heat and pressure are applied, only a specific part of the anisotropic conductive film has conductivity due to the anisotropic conductive medium. Hereinafter, the anisotropic conductive film is described as being subjected to heat and pressure, but other methods may be used to partially conduct the anisotropic conductive film. In this method, for example, either the heat or the pressure may be applied, or UV curing may be performed.

In addition, the anisotropic conduction medium can be, for example, a conductive ball or a conductive particle. According to the example, in the present example, the anisotropic conductive film is a film in which conductive balls are mixed with an insulating base member. When heat and pressure are applied, only specific portions are conductive by the conductive balls. The anisotropic conductive film may be a state in which a plurality of particles coated with an insulating film made of a polymer material are contained in the core of the conductive material. In this case, the insulating film is broken by heat and pressure, . 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 the electrical connection in the Z-axis direction is partially formed by the height difference of the mating member adhered by the anisotropic conductive film.

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

According to the present invention, 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 a material having adhesiveness, and the conductive ball is concentrated on the bottom portion of the insulating base member, and is deformed together with the conductive ball when heat and pressure are applied to the base member So that they have conductivity in the vertical direction.

However, the present invention is not limited thereto. The anisotropic conductive film may be formed by randomly mixing conductive balls into an insulating base member or by forming a plurality of layers in which a conductive ball is placed in a double- ACF) are all available.

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. In addition, solutions containing conductive particles can be solutions in the form of conductive particles or nanoparticles.

Referring again to FIG. 5, the second electrode 140 is located in the insulating layer 160, away 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 disposed.

After the conductive adhesive layer 130 is formed in a state where the auxiliary electrode 170 and the second electrode 140 are positioned in the insulating layer 160, the semiconductor light emitting device 150 is connected to the semiconductor light emitting device 150 in a flip chip form 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 semiconductor layer 155 in which a p-type electrode 156, a p-type electrode 156 are formed, an active layer 154 formed on the p-type semiconductor layer 155, And an n-type electrode 152 disposed on the n-type semiconductor layer 153 and the p-type electrode 156 on the n-type semiconductor layer 153 and 154 in the horizontal direction. In this case, the p-type electrode 156 may be electrically connected to the auxiliary electrode 170 by the conductive adhesive layer 130, and the n-type electrode 152 may be electrically connected to the second electrode 140.

Referring again to FIGS. 2, 3A and 3B, the auxiliary electrode 170 is elongated in one direction, and one auxiliary electrode may be electrically connected to the plurality of semiconductor light emitting devices 150. For example, the p-type electrodes of the right and left semiconductor light emitting elements may be electrically connected to one auxiliary electrode around the auxiliary electrode.

More specifically, the semiconductor light emitting device 150 is inserted into the conductive adhesive layer 130 by heat and pressure, and the semiconductor light emitting device 150 is inserted into the conductive adhesive layer 130 through the p- And only the portion between the n-type electrode 152 and the second electrode 140 of the semiconductor light emitting device 150 has conductivity and the semiconductor light emitting device does not have a conductive property because the semiconductor light emitting device is not press- The conductive adhesive layer 130 not only couples the semiconductor light emitting device 150 and the auxiliary electrode 170 and 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 element array, and the phosphor layer 180 is formed in the light emitting element array.

The light emitting element array may include a plurality of semiconductor light emitting elements having different brightness values. Each of the semiconductor light emitting devices 150 constitutes a unit pixel and is electrically connected to the first electrode 120. For example, the first electrodes 120 may be a plurality of semiconductor light emitting devices, and the semiconductor light emitting devices may be electrically connected to any one of the plurality of first electrodes.

Also, since the semiconductor light emitting devices are connected in a flip chip form, the semiconductor light emitting devices grown on the transparent dielectric substrate can be used. The semiconductor light emitting devices may be, for example, a nitride semiconductor light emitting device. Since the semiconductor light emitting device 150 has excellent brightness, individual unit pixels can be formed with a small size.

According to the structure, the barrier ribs 190 may be formed between the semiconductor light emitting devices 150. In this case, the barrier ribs 190 may separate the 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 can form the partition.

Also, if the base member of the anisotropic conductive film is black, the barrier 190 may have a reflection characteristic and a contrast may be increased without a separate black insulator.

As another example, the barrier ribs 190 may be provided separately from the reflective barrier ribs. In this case, the barrier rib 190 may include a black or white insulation depending on the purpose of the display device. When a barrier of a white insulator is used, an effect of enhancing reflectivity may be obtained. When a barrier of a black insulator is used, a contrast characteristic may be increased while having a reflection characteristic.

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 converts the blue (B) light into the 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 can be laminated on the blue semiconductor light emitting element 151 at a position forming a red unit pixel, A green phosphor 182 capable of converting blue light into green (G) light may be laminated on the blue semiconductor light emitting element 151. [ In addition, only the blue semiconductor light emitting element 151 can be used alone in a portion constituting a blue unit pixel. In this case, the unit pixels of red (R), green (G), and blue (B) can form one pixel. More specifically, phosphors 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. In other words, red (R), green (G), and blue (B) may be arranged in order along the second electrode 140, thereby realizing a unit pixel.

(R), green (G), and blue (B) unit pixels may be implemented by combining the semiconductor light emitting device 150 and the quantum dot QD instead of the fluorescent material. 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 can improve the contrast of light and dark.

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

5A, each of the semiconductor light emitting devices 150 includes gallium nitride (GaN), indium (In) and / or aluminum (Al) are added together to form a high output light Device.

In this case, the semiconductor light emitting device 150 may be a red, green, and blue semiconductor light emitting device to form a unit pixel (sub-pixel), respectively. For example, red, green, and blue semiconductor light emitting elements R, G, and B are alternately arranged, and red, green, and blue unit pixels Form a single 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 having a yellow phosphor layer for each individual 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 element W to form a unit pixel. Further, a unit pixel can be formed by using a color filter in which red, green, and blue are repeated on the white light emitting element W.

Referring to FIG. 5C, a red phosphor layer 181, a green phosphor layer 182, and a blue phosphor layer 183 may be provided on the ultraviolet light emitting element UV. As described above, the semiconductor light emitting device can be used not only for visible light but also for ultraviolet (UV), and can be extended to a form of a semiconductor light emitting device in which ultraviolet (UV) can be used as an excitation source of the upper phosphor .

The semiconductor light emitting device 150 is disposed on the conductive adhesive layer 130 and constitutes a unit pixel in the display device. Since the semiconductor light emitting device 150 has excellent brightness, individual unit pixels can be formed with a small size. The size of the individual semiconductor light emitting device 150 may be 80 mu m or less on one side and may be a rectangular or square device. In the case of a rectangle, the size may be 20 X 80 μm or less.

Also, even if a square semiconductor light emitting device 150 having a length of 10 m on one side is used as a unit pixel, sufficient brightness for forming a display device appears. Accordingly, when the unit pixel is a rectangular pixel having a side of 600 mu m and the other side of 300 mu m as an example, the distance of the semiconductor light emitting element becomes relatively large. Accordingly, in such a case, it becomes possible to implement a flexible display device having HD picture quality.

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

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

The conductive adhesive layer 130 is formed on the insulating layer 160 on which the auxiliary electrode 170 and the second electrode 140 are disposed. A first electrode 120, an auxiliary electrode 170, and a second electrode 140 are formed on the wiring substrate, and the insulating layer 160 is formed on the first substrate 110 to form a single substrate (or a wiring substrate) . In this case, the first electrode 120 and the second electrode 140 may be arranged in mutually orthogonal directions. In addition, the first substrate 110 and the insulating layer 160 may include glass or polyimide (PI), respectively, in order to implement a flexible display device.

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

A second substrate 112 corresponding to the positions of the auxiliary electrode 170 and the second electrodes 140 and having a plurality of semiconductor light emitting elements 150 constituting individual pixels is disposed on the semiconductor light emitting element 150 Is disposed so as to face the auxiliary electrode 170 and the second electrode 140.

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

When the semiconductor light emitting device is formed in units of wafers, the semiconductor light emitting device can be effectively used in a display device by having an interval and a size at which a display device can be formed.

Then, the wiring substrate and the second substrate 112 are thermally bonded. For example, the wiring board and the second substrate 112 may be thermocompression-bonded using an ACF press head. The wiring substrate and the second substrate 112 are bonded by the thermocompression bonding. Only the portion between the semiconductor light emitting device 150 and the auxiliary electrode 170 and the second electrode 140 has conductivity due to the characteristics of the anisotropic conductive film having conductivity by thermocompression, The device 150 may be electrically connected. At this time, the semiconductor light emitting device 150 is inserted into the anisotropic conductive film, and partition walls 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 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 a wiring substrate on which the semiconductor light emitting device 150 is coupled with silicon oxide (SiOx) or the like.

Further, 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 phosphor or a green phosphor for converting the blue (B) A layer can be formed on one surface of the device.

The manufacturing method and structure of the display device using the semiconductor light emitting device described above can be modified into various forms. For example, a vertical semiconductor light emitting device may be applied to the display device described above. Hereinafter, the vertical structure will be described with reference to Figs. 5 and 6. Fig.

In the modifications or embodiments described below, the same or similar reference numerals are given to the same or similar components as those of the previous example, and the description is replaced with the first explanation.

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

Referring to these drawings, the display device may be a display device using a passive matrix (PM) 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. The substrate 210 may include polyimide (PI) to implement a flexible display device. In addition, any insulating and flexible material may be used.

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

A conductive adhesive layer 230 is formed on the substrate 210 on which the first electrode 220 is located. The conductive adhesive layer 230 may be formed of an anisotropic conductive film (ACF), an anisotropic conductive paste, a solution containing a conductive particle, or the like, as in a display device using a flip chip type light emitting device. ) And the like. However, the present embodiment also exemplifies the case where the conductive adhesive layer 230 is realized by the anisotropic conductive film.

If the semiconductor light emitting device 250 is connected to the semiconductor light emitting device 250 by applying heat and pressure after the anisotropic conductive film is positioned in a state where the first electrode 220 is positioned on the substrate 210, And is electrically connected to the electrode 220. In this case, the semiconductor light emitting device 250 may be disposed on the first electrode 220.

As described above, the electrical connection is generated because heat and pressure are applied to the anisotropic conductive film to partially conduct in the thickness direction. Therefore, in the anisotropic conductive film, it is divided into a portion 231 having conductivity in the thickness direction and a portion 232 having no conductivity.

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

Thus, the semiconductor light emitting device 250 is positioned on the conductive adhesive layer 230, thereby forming individual pixels in the display device. Since the semiconductor light emitting device 250 has excellent brightness, individual unit pixels can be formed with a small size. The size of the individual semiconductor light emitting device 250 may be 80 μm or less on one side and may be a rectangular or square device. In the case of a rectangle, the size may be 20 X 80 μm or less.

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

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

9, the vertical type semiconductor light emitting device includes a p-type electrode 256, a p-type semiconductor layer 255 formed on the p-type electrode 256, 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 to the first electrode 220 by the conductive adhesive layer 230, and the n-type electrode 252 located at the top may be electrically connected to the second electrode 240 As shown in FIG. Since the vertical semiconductor light emitting device 250 can arrange the electrodes up and down, it has a great advantage that the chip size can be reduced.

Referring to FIG. 8 again, a phosphor layer 280 may be formed on one side 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) . 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 can be laminated on the blue semiconductor light emitting element 251 at a position forming a red unit pixel, A green phosphor 282 capable of converting blue light into green (G) light may be laminated on the blue semiconductor light emitting element 251. In addition, only the blue semiconductor light emitting element 251 can be used alone in a portion constituting a blue unit pixel. In this case, the unit pixels of red (R), green (G), and blue (B) can form one pixel.

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

The second electrode 240 is located between the semiconductor light emitting devices 250 and electrically connected to the semiconductor light emitting devices 250. For example, the semiconductor light emitting devices 250 may be disposed in a plurality of rows, and the second electrode 240 may be disposed between the columns of the semiconductor light emitting devices 250.

The second electrode 240 may be positioned between the semiconductor light emitting devices 250 because the distance between the semiconductor light emitting devices 250 forming the individual pixels is sufficiently large.

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.

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 part of the ohmic electrode by printing or vapor deposition. Accordingly, the second electrode 240 and the n-type electrode of the semiconductor light emitting device 250 can be electrically connected.

According to the example, the second electrode 240 may be disposed on the conductive adhesive layer 230. A transparent insulating layer (not shown) containing 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 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 for positioning the second electrode 240 on the semiconductor light emitting device 250, the problem that the ITO material has poor adhesion with the n-type semiconductor layer have. Accordingly, the present invention has an advantage in that the second electrode 240 is positioned between the semiconductor light emitting devices 250, so that a transparent electrode such as ITO is not used. Therefore, the light extraction efficiency can be improved by using a conductive material having good adhesiveness with the n-type semiconductor layer as a horizontal electrode without being bound by transparent material selection.

According to the structure, the barrier ribs 290 may be positioned between the semiconductor light emitting devices 250. That is, the barrier ribs 290 may be disposed between the vertical semiconductor light emitting devices 250 to isolate the semiconductor light emitting devices 250 forming the individual pixels. In this case, the barrier ribs 290 may separate the individual unit pixels from each other, and may be formed integrally 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 can form the partition.

Also, if the base member of the anisotropic conductive film is black, the barrier ribs 290 may have a reflection characteristic and a contrast may be increased without a separate black insulator.

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

If the second electrode 240 is directly disposed on the conductive adhesive layer 230 between the semiconductor light emitting devices 250, the barrier ribs 290 may be formed between the vertical semiconductor light emitting device 250 and the second electrode 240 As shown in FIG. Therefore, individual unit pixels can be formed with a small size by using the semiconductor light emitting device 250, and the distance between the semiconductor light emitting device 250 can be relatively large enough so that the second electrode 240 can be electrically connected to the semiconductor light emitting device 250 ), And it is possible to realize a flexible display device having HD picture quality.

In addition, according to the present invention, a black matrix 291 may be disposed between the respective phosphors to improve the contrast. That is, this black matrix 291 can improve the contrast of light and dark.

As described above, the semiconductor light emitting device 250 is disposed on the conductive adhesive layer 230, thereby forming individual pixels in the display device. Since the semiconductor light emitting device 250 has excellent brightness, individual unit pixels can be formed with a small size. Therefore, a full color display in which red (R), green (G), and blue (B) unit pixels form one pixel can be realized by the semiconductor light emitting device.

The display device of the present invention described above can be configured to adjust the brightness of a specific device according to the amount of external light. For example, the display device of the present invention can increase the brightness of the red (R) element during the daytime in which the external light amount is high and decrease the brightness of the red (R) element in the nighttime when the external light amount is small. Conventionally, a separate sensor is used to sense the external light quantity in order to adjust the brightness of the device according to the external light quantity. Such a sensor has to be disposed separately in the display device, which increases the size of the display device. Further, since the position of the sensor for measuring the external light amount is different from the position of the light emitting element, there is a problem that the brightness of the individual element is difficult to accurately adjust according to the external light amount.

The present invention provides a semiconductor light emitting device having a novel structure capable of solving such a problem. Hereinafter, a display device to which a semiconductor light emitting device having a novel structure in which a phosphor and a semiconductor light emitting device are integrated and a method of manufacturing the same will be described.

FIGS. 10 to 12 are cross-sectional views of a display device using the semiconductor light emitting device of the present invention, and FIG. 13 is a conceptual diagram showing electrode arrangement of a display device using a semiconductor light emitting device.

Referring to FIG. 10, the display device of the present invention includes two different types of semiconductor light emitting devices. Specifically, the display device of the present invention includes a wiring board having a plurality of first electrode lines, a plurality of first semiconductor light emitting elements disposed on the wiring board and electrically connected to one of the first electrode lines, A second semiconductor light emitting device 250 for emitting light of a different wavelength band than the first semiconductor light emitting devices 250, a plurality of second semiconductors 250 electrically connected to the other one of the first electrode lines, And a transparent electrode line 340 disposed on the second semiconductor light emitting devices 350 and adapted to allow current generated from the second semiconductor light emitting devices 350 to flow.

In this specification, when the semiconductor light emitting device is arranged on the wiring board, the direction in which the time information is output is defined as the upper side, and the coupling relation of the surfaces of the semiconductor layers described above is defined based on this. For example, a first electrode line is disposed below the first and second semiconductor light emitting elements, and a transparent electrode line is disposed above the second semiconductor light emitting element.

Each of the first electrode lines may be disposed on the wiring substrate in parallel with each other. Some of the first electrode lines are electrically connected to the first semiconductor light emitting element and the other part is electrically connected to the second semiconductor light emitting element. The description of the first electrode line is omitted in the description of the first electrode 220 described with reference to FIG.

The first semiconductor light emitting element may be a flip chip type or a vertical type semiconductor light emitting element described in FIGS. As described with reference to FIGS. 5A to 5C, there are various ways in which the semiconductor light emitting device realizes color. Hereinafter, an embodiment in which the vertical semiconductor light emitting devices are individually colored will be described. However, the present invention is not limited thereto.

When a display is implemented using a vertical type semiconductor light emitting element, the electrode can be arranged as shown in Fig. Specifically, a portion 220 of the first electrode lines is electrically connected to the first semiconductor light emitting device 250 under the first semiconductor light emitting device 250, and another portion 320 of the first electrode lines And is electrically connected to the second semiconductor light emitting device 350 under the second semiconductor light emitting device 350. Meanwhile, the second electrode line 240 is electrically connected to the first semiconductor light emitting device 250 on the first semiconductor light emitting device 250. The transparent electrode line 340 is electrically connected to the second semiconductor light emitting device 350 on the second semiconductor light emitting device 350.

Here, the second electrode line 240 may be made of opaque metal to increase the amount of current flowing through the semiconductor light emitting device. Meanwhile, the transparent electrode line 340 may be made of a light-transmitting material to increase the light detection sensitivity and the light amount of the second semiconductor light emitting device 350.

If the thicknesses of the first semiconductor light emitting device 250 and the second semiconductor light emitting device 350 are different from each other, a portion of the transparent electrode line 340 may be disposed on a different plane from the second electrode line 240 have.

Each of the first semiconductor light emitting elements may emit red (R), green (G), or blue (B) light. For example, the display device of the present invention may include a semiconductor light emitting device that emits green (G) light and a semiconductor light emitting device that emits blue (B) light.

Meanwhile, the second semiconductor light emitting device may emit light of any one of red (R), green (G), and blue (B) light, like the first semiconductor light emitting device. In addition, the second semiconductor light emitting device absorbs light to generate a current. At this time, the amount of current generated in the second semiconductor light emitting device can be increased in proportion to the amount of light absorbed.

As described above, the voltage is applied between the first electrode line electrically connected to the second semiconductor light emitting device and the transparent electrode line, so that the current flows to the second semiconductor light emitting device, Absorbs light and generates current.

A current generated in the second semiconductor light emitting device flows along the first electrode line and the transparent electrode line and an amount of current can be sensed in a control unit electrically connected to the first electrode line and the transparent electrode line.

The control unit controls the magnitude of the voltage applied to each semiconductor light emitting device, and controls the light emission amount and the light amount of the individual light emitting devices. Here, the controller may sense the amount of current generated in the second semiconductor light emitting device, and determine the magnitude of the voltage applied to the second semiconductor light emitting device according to the sensed current amount.

Specifically, the amount of light emitted from the second semiconductor light emitting device varies depending on the magnitude of a voltage applied between the first electrode line and the transparent electrode line. The controller may determine a magnitude of a voltage applied between the first electrode line and the transparent electrode line according to the sensed current amount.

For example, the controller may control a magnitude of a voltage applied to the second semiconductor light emitting device in proportion to an amount of current generated in the second semiconductor light emitting device. In such a case, the display device of the present invention can realize a display that becomes brighter as the external light amount increases.

11 and 12, the display device of the present invention includes a first semiconductor light emitting device that emits green (G) light and a second semiconductor light emitting device that emits blue (B) light, And a second semiconductor light emitting element for emitting light. In addition, the display device of the present invention can increase the amount of current applied to the second semiconductor light emitting device in proportion to the current generated in the second semiconductor light emitting device.

As shown in FIG. 11, the amount of light emitted from the second semiconductor light emitting device 350 can be increased during the daytime when the amount of light absorbed by the second semiconductor light emitting device is large. 12, the amount of light emitted from the second semiconductor light emitting device 350 may be increased during the nighttime when the amount of light absorbed by the second semiconductor light emitting device 350 is small. As described above, the display device of the present invention can adjust the amount of red (R) light according to the amount of external light. Accordingly, the present invention can adjust the color temperature (CCT) and the color rendering index (CRI) according to the amount of external light.

On the other hand, when the display device performs the functions according to Figs. 11 and 12, a separate sensor for sensing the amount of external light is not required. Further, according to the present invention, since the light emitting element itself generates a signal in accordance with the amount of external light, the external light amount can be accurately reflected to the brightness of the light emitting element.

Meanwhile, the second semiconductor light emitting device has a new structure not described in the above-mentioned drawings. Hereinafter, the structure of the display device including the second semiconductor light emitting element and the second semiconductor light emitting element will be described in detail.

14 is a conceptual diagram showing a semiconductor light emitting device having a novel structure.

The second semiconductor light emitting device includes an electron injection layer 351, an active layer 352, a hole transporting layer 353, and a hole injection layer 354.

The electron injection layer 351 serves to supply electrons to the active layer 352 and the hole transport layer 353 and the hole injection layer 354 serve to inject holes into the active layer 352.

Meanwhile, the active layer 352 may be formed of a double-heterojunction nanorod (DHNR). Heterojunction nanorods have a structure in which the quantum dots of the core and shell structure are attached to the ends of the nanorods like dumbbells. Dumbbell shape quantum dots have asymmetric energy differences, unlike symmetrical spherical core shell quantum dots. For example, the nanorods may be made of CdS, the core bonded to the ends of nanorods may be made of CdSe, and the shells may be made of ZnSe.

In this case, the heterojunction nanorods may have both excellent light emission characteristics and optical detection characteristics. When the active layer 352 is composed of the above-described heterojunction nanorods, the active layer 352 can perform both the light emitting function and the light detecting function. Specifically, when a voltage is applied to the active layer 352, current flows to the active layer 352, and the active layer 352 emits light. Alternatively, when the active layer 352 absorbs light, a current is generated.

Meanwhile, the electron injection layer 351 and the hole injection layer 354 are connected to different electrode lines. For example, the electron injection layer 351 may be connected to the first electrode line, and the hole injection layer 354 may be connected to the transparent electrode line.

Light emitted from the second semiconductor light emitting device may be emitted to the outside through the hole transport layer 353 and the hole injection layer 354. Light emitted from the active layer 352 may be transmitted through the hole transport layer 353 and the hole injection layer 354. Therefore, in order to improve brightness and photo-sensing precision of the second semiconductor light emitting device, it is preferable that the electrode electrically connected to the hole injection layer 354 is made of a light-transmitting material.

On the other hand, the structures of the first semiconductor light emitting element and the second semiconductor light emitting element may be different from each other. In particular, the thicknesses of the first semiconductor light emitting element and the second semiconductor light emitting element may be different. As described with reference to FIG. 10, the first and second semiconductor light emitting devices are disposed on the same plane. When the thickness of the semiconductor light emitting device is different, it is difficult to arrange additional structures on the display.

10, the display device of the present invention is disposed on the second semiconductor light emitting elements 350 and is formed to a height at which the first semiconductor light emitting elements 250 are formed And may further include a light transmitting layer 330. In this case, a part of the transparent electrode line 340 may be disposed between the light transmitting layer 330 and the second semiconductor light emitting device 350.

According to the above-described structure, even if the thicknesses of the first and second semiconductor light emitting elements are different, the two kinds of semiconductor light emitting elements can be arranged on the same plane.

Hereinafter, a method of manufacturing a display device according to the present invention will be described.

15A to 15G are cross-sectional views illustrating a method of manufacturing a display device using the semiconductor light emitting device of the present invention.

First, a plurality of first semiconductor light emitting devices are coupled to a portion of the first electrode lines formed on the substrate.

15A, a plurality of recessed portions are formed on a substrate, and a first electrode line 420 is formed on the bottom surface of the recessed portion. A first electrode line formed on a bottom surface of a part of the recessed portions is electrically connected to a first semiconductor light emitting device.

Here, the substrate may include glass or polyimide (PI). In addition, any insulating material such as PEN (polyethylene naphthalate) and PET (polyethylene terephthalate) may be used as long as it is insulating and flexible. Further, the substrate may be either a transparent material or an opaque material. Meanwhile, the first electrode line may be formed of an opaque metal.

Meanwhile, as shown in FIG. 15B, the bonding metal 470 may be disposed on the first electrode line electrically connected to the first semiconductor light emitting device. The bonding metal 470 fixes the first semiconductor light emitting device to the first electrode line and electrically connects the first semiconductor light emitting device and the first electrode line.

Thereafter, as shown in FIG. 15C, a step of forming the reflective layer 460 on the substrate may proceed. The reflective layer 460 may include at least one of PDMS and PMPS, and may include a filler having a particle diameter of several nanometers. The reflective layer 460 reflects light directed toward the underside of the semiconductor light emitting device to improve light extraction efficiency.

Meanwhile, the reflective layer 460 may be formed on the bonding metal 420. In this case, it is difficult for the semiconductor light emitting device and the electrode line to be electrically connected to each other. In order to solve this problem, as shown in FIG. 15D, a PR coating 490 is formed on a region other than the region where the semiconductor light emitting device is coupled, and the bonding metal 470 is exposed to the outside through a photo-litho process. Then, the first semiconductor light emitting device 250 is bonded to the bonding metal 470. After that, PR coating can be removed by F-based dry etching.

The first semiconductor light emitting devices that emit light of different colors by repeating the above-described PR coating, photo-litho, and dry etching can be disposed at desired positions.

Next, a step of combining a plurality of second semiconductor light emitting elements, which emit light of a different wavelength band from the first semiconductor light emitting elements and absorb light, to generate a current, is performed on another part of the first electrode lines .

The step of bonding the second semiconductor light emitting device to the first electrode line may be performed by repeating the above-described PR coating, photo-litho, and dry etching. However, as shown in FIG. 15E, the second semiconductor light emitting device can be directly coupled to the first electrode line without a bonding metal.

Next, as shown in FIG. 15F, the step of arranging the transparent electrode line 440 on the second semiconductor light emitting element is proceeded. The transparent electrode line 440 may be formed before the second electrode line. In order to form an ohmic contact between the first semiconductor light emitting device and the second electrode line, the conductive semiconductor layer of the first semiconductor light emitting device must be exposed to the outside through etching. Alternatively, the second semiconductor light emitting device may form an ohmic contact with the transparent electrode line immediately without such etching.

Next, as shown in FIG. 15G, after the transparent electrode line 440 is formed, a step of applying a light-transmissive material 430 covering the first and second semiconductor light-emitting elements and the step of coating the light- Etching a portion of each of the devices to expose the portion to the outside.

The light-transmitting material covering the first semiconductor light emitting device 250 and a part of the first semiconductor light emitting device 250 are removed through the etching process. Accordingly, the first semiconductor light emitting device 250 and the second electrode line can form an ohmic contact. At this time, the light-transmitting material 430 may remain on the side surface of the first semiconductor light emitting device 250.

The light-transmissive material 430 covering the second semiconductor light emitting device 350 prevents the second semiconductor light emitting device 350 and the transparent electrode line 440 from being damaged during the etching process. The light-transmitting material covering the second semiconductor light-emitting device may remain after the etching process. Such a light-transmitting material solves the problem caused by the difference in thickness of the first and second semiconductor light-emitting devices.

Finally, a step of forming a second electrode line is performed on a part of the first semiconductor light emitting device exposed to the outside by etching.

On the other hand, as shown in FIGS. 16A and 16B, a lens unit 490 made of a light-transmitting material may be disposed on the upper side of the display device manufactured according to the above-described method. The lens portion 490 enhances the optical pick-up efficiency of the semiconductor light emitting device. In an exemplary embodiment, the lens unit 490 may include at least one of a PDMS and a PMPS.

As described above, according to the present invention, in adjusting the brightness of the display device according to the external light amount, a separate sensor for sensing the external light amount is not required. Further, according to the present invention, since the light emitting element itself generates a signal in accordance with the amount of external light, the external light amount can be accurately reflected to the brightness of the light emitting element.

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

Claims (10)

A wiring board having a plurality of first electrode lines;
A plurality of first semiconductor light emitting elements disposed on the wiring board and electrically connected to one of the first electrode lines;
A plurality of second semiconductor light emitting devices emitting light of a different wavelength band than the first semiconductor light emitting devices, electrically connected to the other of the first electrode lines and absorbing light to generate current; And
And a transparent electrode line disposed on the second semiconductor light emitting elements so that a current generated in the second semiconductor light emitting elements flows,
Wherein a light amount of light emitted from the second semiconductor light emitting elements varies depending on an amount of current flowing along the transparent electrode line. The method according to claim 1,
Wherein the second semiconductor light emitting elements emit light when a voltage is applied between the first electrode line and the transparent electrode line. 3. The method of claim 2,
Wherein a magnitude of a voltage applied between the first electrode line and the transparent electrode line varies depending on an amount of current flowing along the transparent electrode line. The method according to claim 1,
Wherein a thickness of the second semiconductor light emitting device is smaller than a thickness of the first semiconductor light emitting device. 5. The method of claim 4,
And a light transmitting layer disposed on the second semiconductor light emitting elements and formed to a height at which the first semiconductor light emitting elements are formed. 6. The method of claim 5,
And a part of the transparent electrode line is disposed between the light transmitting layer and the second semiconductor light emitting element. 6. The method of claim 5,
Further comprising a plurality of second electrode lines electrically connected to the first semiconductor light emitting device on the first semiconductor light emitting device,
Wherein the second electrode lines and the transparent electrode lines are made of different materials. 8. The method of claim 7,
And a part of the transparent electrode line is arranged on a different plane from the second electrode line. The method according to claim 1,
Further comprising a lens unit arranged to cover the first and second semiconductor light emitting elements. The method comprising: coupling a plurality of first semiconductor light emitting elements to a portion of first electrode lines formed on a substrate;
Coupling a plurality of second semiconductor light emitting devices that emit light in a different wavelength band from the first semiconductor light emitting devices and absorb light to generate currents in another portion of the first electrode lines;
Disposing a transparent electrode line on the second semiconductor light emitting device;
Applying a light-transmissive material covering the first and second semiconductor light emitting elements;
Etching the portion of each of the light-transmitting material and the first semiconductor light emitting elements to expose the portion to the outside; And
And forming a second electrode line on the portion exposed to the outside.

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