KR102613757B1 - Display device using semiconductor light emitting device and method for manufacturing - Google Patents

Abstract

The present invention relates to a display device, and particularly to a display device using a semiconductor light emitting device. A display device according to the present invention includes a substrate on which wiring electrodes are formed, a plurality of semiconductor light emitting devices electrically connected to the wiring electrodes, an adhesive layer disposed between the plurality of semiconductor light emitting devices and the wiring electrodes, and a reflective layer including a resin laminated on the adhesive layer to fill the space between the plurality of semiconductor light emitting devices, and reflective particles mixed with the resin.

Description

Display device using semiconductor light emitting device and manufacturing method thereof {DISPLAY DEVICE USING SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING}

The present invention relates to a display device and a manufacturing method thereof, and particularly to a display device using a semiconductor light-emitting device.

Recently, in the field of display technology, display devices with excellent characteristics such as thin film and flexible have been developed. In contrast, currently commercialized major displays are represented by LCD (Liguid Crystal Display) and AMOLED (Active Matrix Organic Light Emitting Diodes). However, in the case of LCD, there are problems such as a slow response time and difficulty in implementing flexibility, and in the case of AMOLED, there are vulnerabilities such as short lifespan, poor mass production yield, and weak flexibility.

Meanwhile, 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, green LEDs of the GaP:N series have been used since then. It has been used as a light source for display images in electronic devices, including communication devices. Accordingly, a method to solve the above problems can be proposed by implementing a flexible display using the semiconductor light emitting device.

A flexible display using the semiconductor light-emitting device may have a need to improve the luminous efficiency of the semiconductor light-emitting device. To solve this need, a method of updating the structure of the semiconductor light-emitting device may be used, but this method has the disadvantage of complicating the manufacture of the semiconductor light-emitting device. Alternatively, a structure that improves the reflective performance of the conductive adhesive layer can be used, but it is difficult to implement in a large-area display. Accordingly, the present invention presents a mechanism for improving luminous efficiency in a display device that has a simple structure but can be applied to a large area.

One object of the present invention is to provide a structure that improves luminance in a display device and a method of manufacturing the same.

Another object of the present invention is to provide a display device and a manufacturing method thereof that are manufactured on a wafer of semiconductor light emitting devices to alleviate light loss on the side of the semiconductor light emitting devices.

The display device according to the present invention increases the brightness of the display device by forming a reflective layer on the wafer.

As a specific example, the display device includes a substrate on which wiring electrodes are formed, a plurality of semiconductor light-emitting devices electrically connected to the wiring electrodes, an adhesive layer disposed between the plurality of semiconductor light-emitting devices and the wiring electrodes, and a reflective layer including a resin laminated on the adhesive layer to fill the space between the plurality of semiconductor light emitting devices, and reflective particles mixed with the resin.

In an embodiment, the wiring electrode formed on the substrate is a first wiring electrode connected to the first electrode of the plurality of semiconductor light-emitting devices, and a second wiring electrode is on one surface of the reflective layer and electrically connects the plurality of semiconductor light-emitting devices. The wiring electrode may be formed along one direction.

Pixels of different colors may be arranged along one direction, and the reflective layer may be formed between pixels of different colors.

Additionally, the display device according to the present invention improves the adhesion of the adhesive layer by using an area without a reflective layer. Specifically, areas without the reflective layer may be sequentially arranged at preset intervals along a direction perpendicular to the one direction. The area without the reflective layer may be formed at a location that does not overlap the second wiring electrode. The area without the reflective layer may be formed at a location that overlaps the first wiring electrode. The adhesive layer may be filled in areas without the reflective layer.

In an embodiment, the reflective layer may have a content of the reflective particles of 10 to 50% wt. The reflective particles are rutile TiO2 and may have a diameter of 10 to 2000 nanometers.

The reflective particles may include white pigment. The resin may include at least one of acrylic, epoxy, polyimide, a polymer mixed coating, or photoresist.

In addition, the present invention includes the steps of sequentially growing an n-type semiconductor layer, an active layer, and a p-type semiconductor layer on a substrate, and etching the p-type semiconductor layer and the active layer to form a plurality of semiconductor light emitting devices on the substrate. and forming an n-wiring electrode extending in one direction from the n-type semiconductor layer to electrically connect the plurality of semiconductor light-emitting devices; forming a reflective layer covering the plurality of semiconductor light-emitting devices; and A step of forming a p wiring electrode electrically connected to the p-type semiconductor layer after removing at least a portion thereof, wherein the reflective layer includes a resin that fills the space between the plurality of semiconductor light emitting devices, and a reflective layer mixed with the resin. A method of manufacturing a display device characterized by having particles is presented. In this case, the reflective layer may be etched so as not to cover at least a portion of the n-wire electrode so that a region without the reflective layer is formed.

In the display device according to the present invention, side light emission in the pixel direction of the semiconductor light emitting device can be reflected using a reflective layer that can be manufactured on a semiconductor wafer. In particular, by changing the optical path due to reflection, light emitted from the side of the semiconductor light-emitting devices is guided upward. In particular, in small-sized semiconductor light-emitting devices, the ratio of light emitted from the side increases, and thus the brightness of the display device can be greatly improved. In addition, since it is manufactured on a semiconductor wafer, it has the advantage of being applicable to large areas and being easy to manufacture compared to the case of using a conductive adhesive layer.

In addition, the present invention has a color mixing prevention function by blocking light in the pixel direction, and can provide a more robust adhesive structure when bonded to an adhesive layer by using an area without a reflective layer.

1 is a conceptual diagram showing an embodiment of a display device using a semiconductor light-emitting device of the present invention.
FIG. 2 is a partial 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.
FIG. 4 is a conceptual diagram showing the flip chip type semiconductor light emitting device of FIG. 3.
FIGS. 5A to 5C are conceptual diagrams showing various forms of implementing color in relation to a flip chip type semiconductor light emitting device.
Figure 6 is a cross-sectional view showing a method of manufacturing a display device using the semiconductor light emitting device of the present invention.
Figure 7 is a perspective view showing another embodiment of a display device using the semiconductor light-emitting device of the invention.
Figure 8 is a cross-sectional view taken along line DD in Figure 7.
FIG. 9 is a conceptual diagram showing the vertical semiconductor light emitting device of FIG. 8.
FIG. 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 of a new structure is applied.
Figure 11a is a cross-sectional view taken along line EE in Figure 10.
Figure 11b is a cross-sectional view taken along line FF in Figure 11.
FIG. 12 is a conceptual diagram showing the flip chip type semiconductor light emitting device of FIG. 11A.
Figure 13 is an enlarged view of portion A of Figure 1 for explaining another embodiment of the present invention.
Figure 14 is a cross-sectional view taken along GG in Figure 13.
Figure 15 is a cross-sectional view taken along line HH in Figure 13, and Figures 16a and 16b are cross-sectional views taken along line H1-H1 and H2-H2 in Figure 13.
FIG. 16C is a plan view showing an area without a reflective layer in FIG. 13.
FIGS. 17 and 18 are conceptual diagrams for explaining the process of manufacturing the semiconductor light emitting device shown in FIGS. 13 to 16C.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, it should be noted that the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical idea disclosed in this specification by the attached drawings.

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

Display devices described in this specification include mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation, and slate PCs. , Tablet PC, Ultra Book, digital TV, desktop computer, etc. However, those skilled in the art will easily understand that the configuration according to the embodiments described in this specification can be applied to devices capable of displaying, even if they are new product types that are developed in the future.

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

According to the illustration, information processed by the control unit of the display device 100 may be displayed using a flexible display.

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

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

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

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

According to the illustrations of FIGS. 2, 3A, and 3B, a display device 100 using a passive matrix (PM) type semiconductor light emitting device is illustrated. However, the examples described below are also applicable to active matrix (AM) type semiconductor light emitting devices.

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 that has insulating properties and is flexible, such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate), can be used. Additionally, the substrate 110 may be made of either a transparent or 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 located on the substrate 110.

According to the illustration, 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 located in the insulating layer 160. In this case, the insulating layer 160 is stacked on the substrate 110 to form a single wiring board. More specifically, the insulating layer 160 is made of an insulating and flexible material such as polyimide (PI), PET, or PEN, and can be integrated with the substrate 110 to form one substrate.

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

Referring to these drawings, a conductive adhesive layer 130 is formed on one surface of the insulating layer 160, but the present invention is not necessarily limited thereto. For example, a structure in which a layer performing a specific function is formed between the insulating layer 160 and the conductive adhesive layer 130, or 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 function as an insulating layer.

The conductive adhesive layer 130 may be a layer having adhesiveness and conductivity. For this purpose, a conductive material and an adhesive material may be mixed in the conductive adhesive layer 130. Additionally, the conductive adhesive layer 130 is flexible, 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, etc. The conductive adhesive layer 130 may be configured as a layer that allows electrical interconnection in the Z direction penetrating the thickness, but has electrical insulation in the horizontal X-Y direction. Therefore, the conductive adhesive layer 130 may be called a Z-axis conductive layer (however, hereinafter referred to as '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 due to the anisotropic conductive medium. Hereinafter, it will be explained that heat and pressure are applied to the anisotropic conductive film, but other methods are also possible to make the anisotropic conductive film partially conductive. This method can be, for example, application of either heat or pressure alone, UV curing, etc.

Additionally, the anisotropic conductive medium may be, for example, conductive balls or conductive particles. According to the figure, 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 due to the conductive balls. An anisotropic conductive film may contain a plurality of particles in which the core of a conductive material is covered by an insulating film made of polymer. In this case, the area where heat and pressure are applied becomes conductive due to the core as the insulating film is destroyed. . At this time, the shape of the core can be modified to form layers that contact each other in the thickness direction of the film. As a more specific example, heat and pressure are applied entirely to the anisotropic conductive film, and an electrical connection in the Z-axis direction is partially formed due to a height difference between the objects adhered by the anisotropic conductive film.

As another example, an anisotropic conductive film may contain a plurality of particles coated with a conductive material in an insulating core. In this case, the conductive material is deformed (pressed) in the area where heat and pressure are applied and becomes conductive in the direction of the thickness of the film. As another example, it is possible for the conductive material to penetrate the insulating base member in the Z-axis direction and be conductive in the thickness direction of the film. In this case, the conductive material may have a pointed end.

According to the figure, the anisotropic conductive film may be a fixed array anisotropic conductive film (fixed array ACF) in which a conductive ball is inserted into one surface of an insulating base member. More specifically, the insulating base member is made of an adhesive material, and the conductive balls are concentrated on the bottom of the insulating base member, and are deformed together with the conductive balls when heat and pressure are applied to the base member. It becomes conductive in the vertical direction.

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

Anisotropic conductive paste is a combination of paste and conductive balls, and can be a paste in which conductive balls are mixed with an insulating and adhesive base material. Additionally, solutions containing conductive particles may be solutions containing conductive particles or nano particles.

Referring to the drawing again, the second electrode 140 is located in the insulating layer 160 and spaced apart from the auxiliary electrode 170. That is, the conductive adhesive layer 130 is disposed on the insulating layer 160 where 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. When enabled, 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 ( 154) includes an n-type semiconductor layer 153 formed on the n-type semiconductor layer 153 and an n-type electrode 152 disposed horizontally spaced 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 again to FIGS. 2, 3A, and 3B, the auxiliary electrode 170 is formed long in one direction, so that one auxiliary electrode can be electrically connected to a plurality of semiconductor light emitting devices 150. For example, p-type electrodes of semiconductor light emitting devices on the left and right around the auxiliary electrode may be electrically connected to one auxiliary electrode.

More specifically, the semiconductor light-emitting device 150 is press-fitted into the conductive adhesive layer 130 by heat and pressure, and through this, the gap between the p-type electrode 156 and the auxiliary electrode 170 of the semiconductor light-emitting device 150 is formed. Only the portion between the n-type electrode 152 and the second electrode 140 of the semiconductor light-emitting device 150 is conductive, and the remaining portion does not have conductivity because the semiconductor light-emitting device is not press-fitted. In this way, the conductive adhesive layer 130 not only bonds the semiconductor light-emitting device 150 and the auxiliary electrode 170 and the semiconductor light-emitting device 150 and the second electrode 140 to each other, but also forms an electrical connection.

Additionally, 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.

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

Additionally, 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. Additionally, 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 formed even in small sizes.

According to the illustration, 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 formed integrally with the conductive adhesive layer 130. For example, the base member of the anisotropic conductive film may form the partition wall by inserting the semiconductor light emitting device 150 into the anisotropic conductive film.

Additionally, if the base member of the anisotropic conductive film is black, the partition wall 190 can have reflective characteristics and increase contrast even without a separate black insulator.

As another example, a reflective partition may be separately provided as the partition wall 190. In this case, the partition 190 may include a black or white insulator depending on the purpose of the display device. When using a partition made of a white insulator, it can have the effect of increasing reflectivity, and when using a partition made of a black insulator, it can have reflective characteristics and increase contrast at the same time.

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 functions to convert 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, at a position forming a red unit pixel, a red phosphor 181 capable of converting blue light into red (R) light can be stacked on the blue semiconductor light emitting device 151, and at a position forming a 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. Additionally, only the blue semiconductor light emitting device 151 may be used alone in the portion forming the blue unit pixel. In this case, red (R), green (G), and blue (B) unit pixels may 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 can be an electrode that controls one color. That is, red (R), green (G), and blue (B) can be arranged in order along the second electrode 140, and through this, a unit pixel can be implemented.

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

Additionally, a black matrix 191 may be disposed between each phosphor layer to improve contrast. In other words, this black matrix 191 can improve contrast between light and dark.

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

Referring to FIG. 5A, each semiconductor light emitting device 150 is mainly made of gallium nitride (GaN), and indium (In) and/or aluminum (Al) are added together to emit high output light that emits various lights, 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 unit pixel (sub-pixel). For example, red, green, and blue semiconductor light emitting devices (R, G, B) are arranged alternately, and unit pixels of red, green, and blue are generated by the red, green, and blue semiconductor light emitting devices. They form one pixel, and through this, 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, a red phosphor layer 181, a green phosphor layer 182, and a blue phosphor layer 183 may be provided on the white light emitting device (W) to form a unit pixel. Additionally, a unit pixel can be formed on the white light emitting device (W) using a color filter that repeats red, green, and blue.

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 an ultraviolet light emitting device (UV) is also possible. In this way, semiconductor light-emitting devices can be used in all areas, not only visible light but also ultraviolet (UV) light, and can be expanded to the form of a semiconductor light-emitting device in which ultraviolet light (UV) can be used as an excitation source for the upper phosphor. .

Looking at this example again, the semiconductor light emitting device 150 is located on the conductive adhesive layer 130 and constitutes a unit pixel in the display device. Since the semiconductor light emitting device 150 has excellent luminance, an individual unit pixel can be formed even in a small size. The size of such an 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 if a square semiconductor light emitting device 150 with a side length of 10 μm is used as a unit pixel, sufficient brightness to form a display device appears. Therefore, taking as an example the case where the size of a unit pixel is a rectangular pixel with one side of 600 μm and the other side of 300 μm, the distance between the semiconductor light emitting devices becomes relatively large enough. Therefore, in this case, it is possible to implement a flexible display device with HD image quality.

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

Figure 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 figure, first, a conductive adhesive layer 130 is formed on the insulating layer 160 where the auxiliary electrode 170 and the second electrode 140 are located. The insulating layer 160 is stacked on the first substrate 110 to form one substrate (or wiring board), and the wiring board includes a first electrode 120, an auxiliary electrode 170, and a second electrode 140. This is placed. In this case, the first electrode 120 and the second electrode 140 may be arranged in directions orthogonal to each other. Additionally, 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. For this purpose, the anisotropic conductive film may be applied to the substrate on which the insulating layer 160 is located.

Next, the second substrate 112, which corresponds to the positions of the auxiliary electrode 170 and the second electrode 140 and on which a plurality of semiconductor light-emitting devices 150 constituting individual pixels are located, is placed on the semiconductor light-emitting device 150. ) is arranged 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 a wafer unit, it can be effectively used in a display device by having a gap and size that can form a display device.

Next, the wiring board and the second board 112 are heat-compressed. For example, the wiring board and the second board 112 can be heat-compressed using an ACF press head. The wiring board and the second board 112 are bonded by the thermal compression. Due to the characteristics of the anisotropic conductive film that becomes conductive by thermocompression, only the portion between the semiconductor light-emitting device 150 and the auxiliary electrode 170 and the second electrode 140 becomes conductive, and through this, the electrodes and the semiconductor light are emitted. Element 150 may be electrically connected. At this time, the semiconductor light-emitting device 150 is inserted into the anisotropic conductive film, and a partition wall can be formed between the semiconductor light-emitting devices 150 through this.

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

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

Additionally, the 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 phosphor or green phosphor for converting the blue (B) light into the color of a unit pixel emits the blue semiconductor light. A layer can be formed on one side of the device.

The manufacturing method or structure of the display device using the semiconductor light emitting device described above can be modified into various forms. As an example, a vertical semiconductor light emitting device may also be applied to the display device described above. Hereinafter, the 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 numbers are assigned to the same or similar components as the previous example, and the description is replaced with the first description.

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

Referring to these 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 is insulating and flexible can be used.

The first electrode 220 is located on the substrate 210 and may be formed as a bar-shaped electrode that is long in one direction. The first electrode 220 may be configured to function as a data electrode.

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

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

As described above, the electrical connection is created because the anisotropic conductive film becomes partially conductive in the thickness direction when heat and pressure are applied. Therefore, the anisotropic conductive film is divided into a conductive portion 231 and a non-conductive portion 232 in the thickness direction.

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

In this way, the semiconductor light emitting device 250 is located on the conductive adhesive layer 230, and thereby constitutes an individual pixel in the display device. Since the semiconductor light emitting device 250 has excellent brightness, individual unit pixels can be formed even in small sizes. The size of such an individual semiconductor light emitting device 250 may have a side length of 80 μm or less and may be a rectangular or square device. In the case of a rectangle, the size may be 20X80㎛ or less.

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

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

Referring to FIG. 9, this 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 to the first electrode 220 and the conductive adhesive layer 230, and the n-type electrode 252 located at the top may be connected to the second electrode 240, which will be described later. ) can be electrically connected to. This vertical semiconductor light emitting device 250 has a great advantage in that it can reduce the chip size because electrodes can be arranged up and down.

Referring again 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 is provided with a phosphor layer 280 to convert this blue (B) light into the color of a unit pixel. It 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 can be stacked on the blue semiconductor light emitting device 251, and at a position forming a 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. Additionally, only the blue semiconductor light emitting device 251 may be used alone in the portion forming the blue unit pixel. In this case, red (R), green (G), and blue (B) unit pixels may form one pixel.

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

Looking at this embodiment again, the second electrode 240 is located 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 forming individual pixels is sufficiently large, the second electrode 240 can 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 arranged in a direction perpendicular to the first electrode.

Additionally, 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 deposition. Through this, the second electrode 240 and the n-type electrode of the semiconductor light emitting device 250 can be electrically connected.

According to the illustration, the second electrode 240 may be positioned on the conductive adhesive layer 230. In some cases, 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 placed after the transparent insulating layer is formed, the second electrode 240 is located on the transparent insulating layer. Additionally, 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 a problem of poor adhesion to the n-type semiconductor layer. there is. Accordingly, the present invention has the advantage of not having to use a transparent electrode such as ITO by placing the second electrode 240 between the semiconductor light emitting devices 250. Therefore, light extraction efficiency can be improved by using a conductive material with good adhesion to the n-type semiconductor layer as a horizontal electrode without being restricted by the selection of a transparent material.

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

Additionally, if the base member of the anisotropic conductive film is black, the partition 290 can have reflective characteristics and increase contrast even without a separate black insulator.

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

If the second electrode 240 is located directly on the conductive adhesive layer 230 between the semiconductor light emitting devices 250, the partition wall 290 is located between the vertical semiconductor light emitting devices 250 and the second electrode 240. It can be located in between. Therefore, an individual unit pixel can be formed even in a small size using the semiconductor light-emitting device 250, and the distance between the semiconductor light-emitting devices 250 is relatively large enough to connect the second electrode 240 to the semiconductor light-emitting device 250. ), and has the effect of implementing a flexible display device with HD image quality.

Additionally, according to the illustration, a black matrix 291 may be disposed between each phosphor to improve contrast. In other words, this black matrix 291 can improve contrast between light and dark.

As described above, the semiconductor light emitting device 250 is located on the conductive adhesive layer 230 and constitutes an individual pixel in the display device. Since the semiconductor light emitting device 250 has excellent luminance, individual unit pixels can be formed even in small sizes. Therefore, a full-color display in which red (R), green (G), and blue (B) unit pixels form one pixel can be implemented using a semiconductor light-emitting device.

When the flip chip type display device using the semiconductor light emitting device of the present invention described above is applied, there is a problem in that it is difficult to implement high definition (fine pitch) because the first and second electrodes are arranged on the same plane. Hereinafter, a display device using a flip chip type light emitting device according to another embodiment of the present invention that can solve this problem will be described.

FIG. 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 of a new structure is applied, FIG. 11A is a cross-sectional view taken along line E-E of FIG. 10, and FIG. 11B is a FIG. It is a cross-sectional view taken along line F-F of 11, and FIG. 12 is a conceptual diagram showing the flip chip type semiconductor light emitting device of FIG. 11A.

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

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

The substrate 1010 is a wiring 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 is insulating and flexible can be used.

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

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

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

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

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

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

As shown, the plurality of semiconductor light emitting devices 1050 may form a plurality of rows in a direction parallel to the plurality of electrode lines provided on the first electrode 1020. However, the present invention is not necessarily limited thereto. For example, a plurality of semiconductor light emitting devices 1050 may form a plurality of rows 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 that emits blue (B) light, and the phosphor layer 1080 functions to convert the blue (B) light into the color of a unit pixel. The phosphor layer 1080 may be a red phosphor 1081 or a green phosphor 1082 constituting an individual pixel. That is, a red phosphor 1081 capable of converting blue light into red (R) light can be stacked on the blue semiconductor light emitting device 1051a at a position forming a red unit pixel, and a position forming a green unit pixel. In , a green phosphor 1082 capable of converting blue light into green (G) light may be stacked on the blue semiconductor light emitting device 1051b. Additionally, only the blue semiconductor light emitting device 1051c can be used alone in the portion forming the blue unit pixel. In this case, red (R), green (G), and blue (B) unit pixels may form one pixel. More specifically, phosphors of one color may be stacked along each line of the first electrode 1020. Accordingly, one line in the first electrode 1020 can be an electrode that controls one color. That is, red (R), green (G), and blue (B) can be arranged in order along the second electrode 1040, and through this, a unit pixel can be implemented. However, the present invention is not necessarily limited to this, and instead of the phosphor, a semiconductor light emitting device 1050 and quantum dot (QD) are combined to create a unit pixel that emits red (R), green (G), and blue (B). It 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 each phosphor layer. The black matrix 1091 may be formed to create a gap between phosphor dots and fill the gap with a black material. Through this, the black matrix 1091 can absorb external light reflection and improve the contrast of light and dark at the same time. This black matrix 1091 is located between each phosphor layer 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 is sandwiched between the spaces without the phosphor layer (or with the blue semiconductor light-emitting device 1051c between them). ) can be formed on both sides.

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

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

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

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

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

Referring to FIG. 12 together with FIGS. 10 to 11B, one side of the second conductive semiconductor layer may be the side closest to the wiring board, and the other side of the second conductive semiconductor layer may be closest to the wiring board. It can be far away.

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

Using the height difference, the second conductive electrode 1152 is formed on the second conductive semiconductor layer 1153, but is disposed adjacent to the second electrode 1040 located on the upper side of the semiconductor light emitting device. . For example, at least a portion of the second conductive electrode 1152 extends from the side of the second conductive semiconductor layer 1153 (or the side of the undoped semiconductor layer 1153a) in the width direction. It protrudes along. In this way, since the second conductive electrode 1152 protrudes from the side, the second conductive electrode 1152 may be exposed to the upper side of the semiconductor light emitting device. Through this, the second conductive electrode 1152 is disposed in a position overlapping with the second electrode 1040 disposed on the upper side of the conductive adhesive layer 1030.

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

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

The structure provided with the protrusion 1152a can be a structure that can utilize the advantages of the horizontal semiconductor light emitting device and the vertical semiconductor light emitting device described above. Meanwhile, fine grooves may be formed on the upper surface of the undoped semiconductor layer 1153a furthest from the first conductive electrode 1156 by roughing.

According to the display device described above, the size of the semiconductor light emitting element is small, so it is difficult to increase the luminance of the display device. This is because the area of the upper surface from which light is emitted from the semiconductor light emitting device is small, so there is a limit to the increase in luminance. Additionally, semiconductor light emitting devices have a structure that emits light from the side, and therefore, light leakage to other pixels may occur. In order to prevent light from leaking to the sides, methods such as modifying the conductive adhesive or modifying the semiconductor light emitting device may be considered, but these methods have the disadvantage of complicating the manufacturing of the display device. The present invention proposes a new mechanism to solve this problem. Hereinafter, a display device using a new mechanism and its manufacturing method will be described.

Hereinafter, the structure of the display device of the present invention will be examined in detail with the attached drawings. FIG. 13 is an enlarged view of portion A of FIG. 1 for explaining another embodiment of the present invention, FIG. 14 is a cross-sectional view taken along line G-G of FIG. 13, and FIG. 15 is a cross-sectional view taken along line H-H of FIG. 13. 16A and 16B are cross-sectional views taken along lines H1-H1 and H2-H2 of FIG. 13, and FIG. 16C is a plan view showing a region without a reflective layer in FIG. 13.

According to the illustrations of FIGS. 13, 14, 15, 16A, 16B, and 16C, the luminance is increased in the flip chip type semiconductor light emitting device described with reference to FIGS. 10 to 12 as a display device using a semiconductor light emitting device. This example illustrates a case where a mechanism is added. In this case, the arrows shown in Figure 14 indicate the light path that increases luminance. However, the examples described below are also applicable to display devices using other types of semiconductor light-emitting devices described above.

In this example described below, the same or similar reference numerals are assigned to components that are the same or similar to each component of the example previously described with reference to FIGS. 10 to 12, and the description is replaced with the first description. For example, the display device 2000 includes a substrate 2010, a first electrode 2020, a conductive adhesive layer 2030, a second electrode 2040, and a plurality of semiconductor light emitting devices 2050, The description is replaced with the description referring to FIGS. 10 to 12 above. However, in this embodiment, the conductive adhesive layer 2030 may be provided as an example of an adhesive layer. For example, the conductive adhesive layer 2030 is replaced with a layer that has only adhesive properties without conductivity, and a plurality of semiconductor light emitting devices are attached to the adhesive layer disposed on the substrate 2010. In this case, the first electrode 2020 may not be located on the substrate 2010, but may be formed integrally with the conductive electrode of the semiconductor light emitting device.

The semiconductor light emitting device 2050 includes a first conductive electrode 2156, a first conductive semiconductor layer 2155 on which the first conductive electrode 2156 is formed, and a first conductive semiconductor layer 2155 on which the first conductive electrode 2156 is formed. It includes an active layer 2154 formed on the active layer 2154, a second conductive semiconductor layer 2153 formed on the active layer 2154, and a second conductive electrode 2152 formed on the second conductive semiconductor layer 2153, The description of these is replaced with the description referring to FIG. 12 above.

In addition, as described above with reference to FIG. 12, a protrusion 2152a extends laterally from one surface of the second conductive semiconductor layer 2153 and extends to the upper surface of the second conductive semiconductor layer 2153. Specifically, it extends to the undoped semiconductor layer 2153a. Accordingly, the protrusion 2152a may be electrically connected to the second electrode 2040 on the opposite side of the first conductive electrode based on the second conductive semiconductor layer. Additionally, in this case, a passivation layer 2158 may be provided and formed to surround the outer surface of the semiconductor light emitting device.

Additionally, the display device 2000 may further include a phosphor layer 2080 formed on one surface of the plurality of semiconductor light emitting devices 2050. For example, the semiconductor light-emitting device 2050 is a blue semiconductor light-emitting device that emits blue (B) light, and the phosphor layer 2080 functions to convert the blue (B) light into the color of a unit pixel. In this case, the light output from the semiconductor light emitting devices 2050 is excited using a phosphor to implement red (R) and green (G) colors. Meanwhile, the phosphor layer 2080 can be replaced with a color filter or quantum dot. In addition, the black matrices 191, 291, and 1091 described above (see FIGS. 3B, 8, and 11B) serve as partition walls to prevent color mixing between phosphors.

Meanwhile, according to the illustration, the color filter 20CF is arranged to cover the phosphor layer 2080. More specifically, the color filter 20CF and the phosphor layer 2080 may be combined by adhesion. In this case, the color filter 20CF is configured to selectively transmit light to implement red, green, and blue colors. The color filter 20CF includes a plurality of filtering units that filter red, green, and blue wavelengths, and may have a structure in which the plurality of filtering units 20CF1, 20CF2, and 20CF3 are repeatedly arranged. At this time, a red filtering unit 20CF1 and a green filtering unit 20CF2 for filtering red and green are disposed on the upper side of the red phosphor layer 2080a and the green phosphor layer 2080b, respectively, and in the part forming the blue pixel, A blue filtering unit 20CF3 may be disposed. Black matrices 20BM1, 20BM2, and 20BM3 may be disposed between the plurality of filtering units 20CF1, 20CF2, and 20CF3. In this case, the phosphor layer 2080 is combined with the color filter 20CF to implement red, green, and blue unit pixels.

As another example, all phosphor layers may be filled with yellow phosphor, not red or green, and a color filter (CF) that repeats red, green, and blue may be arranged to cover the phosphor layer 2080.

Referring to these drawings, the conductive adhesive layer 2030 attaches the semiconductor light emitting devices 2050 to the substrate 2010 (wiring board) and electrically connects the substrate 2010 and the semiconductor light emitting devices 2050. Connect. In this case, the conductive adhesive layer 2030 may be an anisotropic conductive film.

As described above, the first electrode 2020 may not be located on the substrate 2010, but may be deposited on a conductive electrode of a semiconductor light emitting device. For example, the first electrode 2020 is electrically connected to the wiring 2020a of the substrate 2010, and thus can be a wiring electrode. The first electrode 2020 is electrically connected to the wiring 2020a of the substrate 2010 through the anisotropic conductive medium 2034 of the conductive adhesive layer 2030, and is driven as a data electrode for transmitting data signals. You can.

The wiring 2020a formed on the substrate 2010 is a first wiring electrode connected to the first electrode 2020 of the plurality of semiconductor light-emitting devices, and the conductive adhesive layer is connected to the plurality of semiconductor light-emitting devices and the first electrode 2020a. It is disposed between the wiring electrodes.

According to FIGS. 15 and 16A, a reflective layer 2060 may be laminated on the conductive adhesive layer 2030. For example, the reflective layer 2060 may include resin 2061 and reflective particles 2062. The resin 2061 is laminated on the conductive adhesive layer 2030 to fill the space between the plurality of semiconductor light emitting devices, and the reflective particles 2062 can be mixed with the resin 2061.

A second wiring electrode that electrically connects the plurality of semiconductor light emitting devices may be formed along one direction on one surface of the reflective layer 2060.

More specifically, as shown in Figure 16b, the second electrode 2040 is located on the reflective layer 2060 and may be the second wiring electrode. The second electrode extends toward neighboring semiconductor light emitting devices to connect a plurality of semiconductor light emitting devices to each other, and thus functions as an upper wiring.

In this case, the reflective layer 2060 is disposed between the wiring board and the second electrode 2040. The second electrode 2040 can be electrically connected to the semiconductor light emitting device 2050 by contacting it, and can be driven as a scan electrode that transmits a scan signal. However, the present invention is not necessarily limited to this, and it is possible for the first electrode 2020 to be a scan electrode and the second electrode 2040 to be a data electrode.

The first conductive electrode 2156 and the second conductive electrode 2152 may overlap in a thickness direction perpendicular to the one direction with the reflective layer interposed therebetween. In this way, since the first conductive electrode 2156 and the second conductive electrode 2152 are spaced apart by the reflective layer, the n-type electrode and the p-type electrode of the semiconductor light emitting device can be insulated.

Meanwhile, in the semiconductor light emitting device having the above structure, the first electrode and the second electrode extend toward adjacent semiconductor light emitting devices so as to be electrically connected to the adjacent semiconductor light emitting devices.

In this example, reflective particles 2062 are incorporated into the reflective layer 2060 to reflect light emitted from the semiconductor light emitting devices 2050. In this case, the reflective particles 2062 may include at least one of titanium oxide, alumina, magnesium oxide, antimony oxide, zirconium oxide, and silica. Meanwhile, the reflective particles 2062 may be white pigment.

As a more specific example, the reflective particle 2062 is rutile TiO2 and may have a diameter of 10 to 2000 nanometers. At sizes of 2000 nanometers or less, TiO2 has excellent scattering in the blue wavelength band, and rutile TiO2 has the advantage of forming photo-litho or patterns.

The resin 2061 may include at least one of acrylic, epoxy, polyimide, a polymer mixed coating, or photoresist. In this example, the resin 2061 is made of photoresist, and the reflective layer 2060 may have a content of the reflective particles 2062 of 10 to 50% wt compared to the photoresist.

Meanwhile, the resin 2061 may be formed of the same material as the insulating base member of the conductive adhesive layer 2030. In this case, the resin 2061 and the conductive adhesive layer 2030 can be integrated by cementation.

Since reflective particles 2061 are added only to the reflective layer 2060, there is no need to mix reflective particles with the conductive adhesive layer, thereby improving adhesiveness and providing a reflective effect only to the layer in direct contact with the side of the semiconductor light emitting device, thereby increasing luminance. Improvement effects can occur.

Meanwhile, the reflective particle 2061 may serve to reflect light reflected from the phosphor layer 2080 and heading toward the inside of the display device back to the phosphor layer 2080. In this case, the white pigment of the reflective layer is reflected from the phosphor layer 2080 and may mainly serve to re-reflect light directed to the inside of the display device.

Meanwhile, the reflective layer is laminated on a conductive adhesive layer and fills the space between the semiconductor light emitting devices, so it can be formed on a semiconductor wafer. This will be explained in more detail in the manufacturing method described later.

In addition, in the present invention, the reflective layer is formed in a structure that can serve as an anchor, and a mechanism is provided to provide a more robust adhesive structure when combined with the adhesive layer.

For example, as shown in FIGS. 16B and 16C, the areas 2063 without the reflective layer may be sequentially arranged at preset intervals along a direction perpendicular to one direction in which the second wiring electrode is formed. That is, the area 2063 without the reflective layer may be formed at a location that does not overlap the second wiring electrode and a location that overlaps the first wiring electrode.

In this case, the first conductive semiconductor layer 2155 and the first conductive electrode 2156 may be a 'p-type semiconductor layer' and a 'p-type electrode', respectively, and the second conductive semiconductor layer (2153) and the second conductive electrode 2152 may be an 'n-type semiconductor layer' and an 'n-type electrode', respectively. Accordingly, the reflective layer 2060 is formed between the bottom of the p common electrode and the n electrode, and does not exist on the top of the n common electrode.

As shown, the conductive adhesive layer may be filled in the area 2063 without the reflective layer. Accordingly, the reflective layer 2060 is provided with a plurality of grooves, and these form a region 2063 without a reflective layer. Additionally, since the plurality of grooves are filled with the conductive adhesive layer, the conductive adhesive layer may be formed as a structure having a plurality of protrusions. Since the plurality of protrusions are coupled to the plurality of grooves like anchors, adhesive force can be increased.

Additionally, as shown in Figure 15, pixels of different colors are arranged along one direction, and the reflective layer may be formed to fill the space between the pixels of different colors. A red filtering unit 20CF1, a green filtering unit 20CF2, and a blue filtering unit 20CF3 may be sequentially arranged along the second wiring electrode. That is, the structure may be such that a red phosphor layer or a green phosphor layer extends along the first wiring electrode. According to this structure, it has a color mixing prevention function by blocking light in the pixel direction, and can provide a more robust adhesive structure when combined with an adhesive layer by using an area without a reflective layer.

Hereinafter, a manufacturing method for forming a display device including a semiconductor light-emitting device having the structure shown in FIGS. 13 to 16 will be examined in more detail with the accompanying drawings. FIGS. 17 and 18 are conceptual diagrams for explaining the process of manufacturing the semiconductor light emitting device shown in FIGS. 13 to 16.

First, according to the manufacturing method, an n-type semiconductor layer 2153, an active layer 2154, and a p-type semiconductor layer 2155 are each grown on the growth substrate 2059 (FIG. 17(a)).

When the n-type semiconductor layer 2153 is grown, an active layer 2154 is grown on the n-type semiconductor layer 2153, and then a p-type semiconductor layer 2155 is grown on the active layer 2154. I order it. In this way, when the n-type semiconductor layer 2153, the active layer 2154, and the p-type semiconductor layer 2155 are grown sequentially, a stacked structure of a micro semiconductor light emitting device is formed, as shown in (a) of FIG. 17. do.

The growth substrate 2059 (wafer) may be formed of a material having light-transmissive properties, for example, sapphire (Al2O3), GaN, ZnO, or AlO, but is not limited thereto. Additionally, the growth substrate 2059 may be formed of a carrier wafer, a material suitable for growing semiconductor materials. It can be formed of a material with excellent thermal conductivity, including a conductive substrate or an insulating substrate, for example, a SiC substrate with greater thermal conductivity than a sapphire (Al2O3) substrate, or at least one of Si, GaAs, GaP, InP, and Ga2O3. You can use it.

Next, at least a portion of the active layer 2154 and the p-type semiconductor layer 2155 are removed so that at least a portion of the n-type semiconductor layer 2153 is exposed (FIG. 17(b)).

In this case, a portion of the active layer 2154 and the p-type semiconductor layer 2155 is removed in the vertical direction, and the n-type semiconductor layer 2153 is exposed to the outside. Through this, isolation is performed so that a plurality of light-emitting devices form a light-emitting device array. That is, the p-type semiconductor layer 2155 and the active layer 2154 are etched to form a plurality of micro semiconductor light emitting devices.

Next, to implement a flip chip type light emitting device, an n-type electrode 2152 having a height difference in the thickness direction between the n-type semiconductor layer 2153 and the p-type semiconductor layer 2155 and Each p-type electrode 2156 is formed (Figure 17(c)).

The n-type electrode 2152 and the p-type electrode 2156 may be formed by a deposition method such as sputtering, but the present invention is not necessarily limited thereto.

Next, with the n-type electrode 2152 and the p-type electrode 2156 formed, a resin mixed with reflective particles is applied to form a reflective layer 2060 (FIG. 18(a)).

A plurality of semiconductor light-emitting devices forming a light-emitting device array may be arranged to be spaced apart from adjacent light-emitting devices with a certain space between them. As shown, the space between the spaced apart semiconductor light-emitting devices may be filled with a reflective layer 2060. there is. That is, the reflective layer 2060 may be disposed between semiconductor light-emitting devices to function as a partition.

Here, the reflective layer 2060 may be applied to cover all semiconductor light emitting devices formed on the growth substrate 2059.

Next, at least a portion of the reflective layer 2060 is etched to expose the p-type electrode 2156 (FIG. 18(b)). After at least a portion of the reflective layer 2060 is removed, a first electrode 2020 is formed, which is electrically connected to the p-type electrode 2156 (FIG. 18(c)). The first electrode 2020 is formed on one surface of the p-type electrode and may be formed of an electrode line extending in a row direction intersecting the column direction in which the second electrode 2040 is disposed in the light emitting device array. As shown, the first electrode 2020 electrically connects a plurality of light emitting devices included in each row and may be a p wiring electrode. In this way, the first electrode 2020 that electrically connects a plurality of semiconductor light emitting devices arranged along the row direction can serve as a data electrode in the display device 2000 of the present invention.

In this case, the reflective layer can also be removed from the area where the second electrode 2040 is disposed. Through this, an area without a reflective layer is formed, and the area without a reflective layer may be extended along the column direction in which the second electrode 2040 is disposed. Additionally, areas without the reflective layer may be sequentially arranged along the row direction.

Finally, as shown in (d) of FIG. 18, the semiconductor light emitting device is bonded to the wiring board using a conductive adhesive layer while removing the growth substrate 2059.

During the bonding, the wiring electrode 2020a of the wiring board and the p-type electrode 2020 of the semiconductor light emitting device are electrically connected, so that the wiring electrode of the wiring board can become a p common electrode. Additionally, the conductive adhesive layer may be filled in the area 2063 without the reflective layer (see FIGS. 16B and 16C) to increase adhesive strength.

After the bonding process, a second electrode 2040 (see FIG. 16B) extending in one direction from the n-type semiconductor layer and electrically connecting the plurality of semiconductor light emitting devices may be connected to the n-type electrode 2152. In this case, the second electrode may be an n common electrode, and as described above, areas without the reflective layer may be formed sequentially along the second electrode.

According to the manufacturing process described above, the reflective layer is formed on a semiconductor wafer, and therefore has the advantage of being applicable to a large area and being easy to manufacture compared to the case of using a conductive adhesive layer.

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

Claims (13)

A substrate on which wiring electrodes are formed;
a plurality of semiconductor light emitting devices electrically connected to the wiring electrode;
an adhesive layer disposed between the plurality of semiconductor light emitting devices and the wiring electrode; and
A resin laminated on the adhesive layer to fill the space between the plurality of semiconductor light emitting devices, and a reflective layer including reflective particles mixed with the resin,
The reflective layer includes a plurality of grooves formed by a plurality of reflective layer-free areas,
The adhesive layer is,
A display device characterized in that it is formed in a structure having a plurality of protrusions filled in the plurality of regions without a reflective layer and coupled to a plurality of grooves of the reflective layer formed by the plurality of regions without a reflective layer. According to paragraph 1,
The wiring electrode formed on the substrate is a first wiring electrode connected to the first electrode of the plurality of semiconductor light emitting devices,
A display device, wherein a second wiring electrode is formed along one direction on one surface of the reflective layer to electrically connect the plurality of semiconductor light emitting devices. According to paragraph 2,
Areas without the reflective layer are sequentially arranged at preset intervals along a direction perpendicular to the one direction,
A display device, wherein the area without the reflective layer is formed at a location that does not overlap the second wiring electrode. According to paragraph 3,
A display device, wherein the area without the reflective layer is formed at a location that overlaps the first wiring electrode. According to paragraph 2,
A display device, wherein pixels of different colors are arranged along the one direction, and the reflective layer is formed between the pixels of different colors. According to paragraph 1,
A display device, wherein the reflective layer has a content of the reflective particles of 10 to 50% wt. According to clause 6,
The reflective particles are rutile TiO2 and have a diameter of 10 to 2000 nanometers,
A display device wherein the reflective particles include white pigment. According to paragraph 1,
A display device characterized in that the resin includes at least one of acrylic, epoxy, polyimide, a polymer mixed coating, or photoresist. sequentially growing an n-type semiconductor layer, an active layer, and a p-type semiconductor layer on a substrate;
etching the p-type semiconductor layer and the active layer to form a plurality of semiconductor light emitting devices on the substrate;
forming an n wiring electrode extending in one direction from the n-type semiconductor layer to electrically connect the plurality of semiconductor light emitting devices;
forming a reflective layer covering the plurality of semiconductor light emitting devices;
removing at least a portion of the reflective layer; and,
Comprising the step of bonding the plurality of semiconductor light emitting devices on the substrate through an adhesive layer to form a p wiring electrode electrically connected to the p-type semiconductor layer,
The step of removing at least a portion of the reflective layer includes:
Further comprising forming a plurality of areas without a reflective layer by removing a portion of the reflective layer where a specific electrode is disposed,
The step of joining the plurality of semiconductor light emitting devices is,
A method of manufacturing a display device, comprising filling the areas without a reflection layer with the adhesive layer to form an adhesive layer having a structure having a plurality of protrusions coupled to the areas without the reflection layer. According to clause 9,
A method of manufacturing a display device, wherein the reflective layer is etched so as not to cover at least a portion of the n-wire electrode so that a region without the reflective layer is formed. delete delete delete

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