WO2024080391A1

WO2024080391A1 - Display device comprising semiconductor light-emitting element

Info

Publication number: WO2024080391A1
Application number: PCT/KR2022/015276
Authority: WO
Inventors: 최진혁
Original assignee: 엘지전자 주식회사; 엘지디스플레이 주식회사
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2024-04-18

Abstract

An embodiment relates to a display device comprising a semiconductor light-emitting element. A display device comprising a semiconductor light-emitting element according to an embodiment may comprise: a substrate; a first electrode and a second electrode which are disposed spaced apart from each other on the substrate; a first insulation layer disposed on the first and second electrodes; an assembly partition wall which includes a predetermined assembly hole and is disposed on the first insulation layer; a semiconductor light-emitting element disposed within the assembly hole; side surface wiring electrically connected to a side surface of the semiconductor light-emitting element; and a second panel electrode electrically connected to the upper side of the semiconductor light-emitting element. The semiconductor light-emitting element may include a light-emitting structure and a heat transfer insulation layer disposed outside the light-emitting structure.

Description

Display device including semiconductor light emitting device

The embodiment relates to a display device including a semiconductor light emitting device.

Large-area displays include liquid crystal displays (LCDs), OLED displays, and Micro-LED displays.

A micro-LED display is a display that uses micro-LED, a semiconductor light emitting device with a diameter or cross-sectional area of 100㎛ or less, as a display element.

Because micro-LED displays use micro-LED, a semiconductor light-emitting device, as a display device, they have excellent performance in many characteristics such as contrast ratio, response speed, color gamut, viewing angle, brightness, resolution, lifespan, luminous efficiency, and luminance.

In particular, the micro-LED display has the advantage of being able to freely adjust the size and resolution and implement a flexible display because the screen can be separated and combined in a modular manner.

However, because large micro-LED displays require more than millions of micro-LEDs, there is a technical problem that makes it difficult to quickly and accurately transfer micro-LEDs to the display panel.

Transfer technologies that have been recently developed include the pick and place process, laser lift-off method, or self-assembly method.

Among these, the self-assembly method is a method in which the semiconductor light-emitting device finds its assembly position within the fluid on its own, and is an advantageous method for implementing a large-screen display device.

Recently, a micro-LED structure suitable for self-assembly has been proposed in US Patent No. 9,825,202, etc., but research on technology for manufacturing displays through self-assembly of micro-LEDs is still insufficient.

In particular, in the case of rapidly transferring millions of semiconductor light emitting devices to a large display in the prior art, the transfer speed can be improved, but the transfer error rate can increase, which lowers the transfer yield. There is a technical problem.

In related technologies, a self-assembly transfer process using dielectrophoresis (DEP) is being attempted, but there is a problem with a low self-assembly rate due to non-uniformity of the DEP force.

Meanwhile, according to undisclosed internal technology, DEP Force is required for self-assembly, but due to the difficulty in uniformly controlling the DEP Force, when assembling using self-assembly, a phenomenon occurs in which the semiconductor light emitting device is tilted to an incorrect position within the assembly hall. There is a problem.

Additionally, due to this phenomenon of tilting of the semiconductor light emitting device, there is a problem that the electrical contact characteristics deteriorate in the subsequent electrical contact process and the lighting rate decreases.

Therefore, according to undisclosed internal technology, DEP Force is required for self-assembly, but when DEP Force is used, it faces a technical contradiction in that the electrical contact characteristics are deteriorated due to the tilting phenomenon of the semiconductor light emitting device.

Meanwhile, internal technology is researching side wiring technology that connects the panel wiring to the side of the light emitting device chip after self-assembly using DEP force. However, in the side wiring process of the internal technology, there is a problem of disconnection of the wiring at the bottom edge of the light emitting device chip.

In addition, in internal technology, when the electrode process of the panel stage is performed after assembly using DEP force, the power to the assembly electrode is cut off, and if there is no DEP force, the fixing force between the semiconductor light emitting device and the dielectric layer on the assembly electrode is weak, and the semiconductor light emitting device assembled in the assembly hole is emitted. There is a problem of elements being separated.

One of the technical challenges of the embodiment is to solve the problem of a decrease in the lighting rate due to a decrease in electrical contact characteristics between the electrodes of the self-assembled light emitting device and the predetermined panel electrode.

In addition, one of the technical challenges of the embodiment is the problem of disconnection of the side wiring at the bottom edge of the light emitting device chip in the side wiring technology that connects the panel wiring to the side of the light emitting device chip after self-assembly using DEP force in the internal technology. It is intended to solve the problem.

In addition, one of the technical challenges of the embodiment is that, in the internal technology, when the power to the assembly electrode is cut off after self-assembly and there is no DEP force, the fixing force between the semiconductor light emitting device and the dielectric layer on the assembly electrode is weak, and the semiconductor light emitting device assembled in the assembly hole falls off. It is intended to solve the problem.

The technical problems of the embodiments are not limited to those described in this item and include those that can be understood through the entire specification.

A display device including a semiconductor light emitting device according to an embodiment includes a substrate, first electrodes and second electrodes spaced apart from each other on the substrate, and a first insulating layer disposed on the first and second electrodes. and an assembly partition including a predetermined assembly hole and disposed on the first insulating layer, a semiconductor light emitting device disposed in the assembly hole, a side wiring electrically connected to a side of the semiconductor light emitting device, and the semiconductor light emitting device. It may include a second panel electrode electrically connected to the upper side of the device.

The semiconductor light emitting device may include a light emitting structure and a heat transfer insulating layer disposed on the outside of the light emitting structure.

The light emitting structure includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between them, and the side wiring may be electrically connected to the first conductivity type semiconductor layer of the semiconductor light emitting device. .

The side wiring may include a first side wiring disposed on a side of the semiconductor light emitting device and a second side wiring electrically contacting one or more of the first and second electrodes.

The embodiment further includes a passivation layer disposed between the light emitting structure and the heat transfer insulating layer, and the heat transfer efficiency of the passivation layer may be lower than that of the heat transfer insulating layer.

The side wiring may be disposed on the side of the light emitting structure and on the heat transfer insulating layer.

In addition, a display device including a semiconductor light emitting device according to an embodiment includes a substrate, first electrodes and second electrodes spaced apart from each other on the substrate, and first insulators disposed on the first and second electrodes. It may include a layer, an assembly partition including a predetermined assembly hole and disposed on the first insulating layer, and a semiconductor light emitting device disposed within the assembly hole.

The semiconductor light emitting device includes a light emitting structure and a heat transfer insulating layer disposed on the outside of the light emitting structure, and the lower end of the heat transfer insulating layer may be disposed to extend to the bottom of the light emitting structure.

The side wiring may be disposed on the side of the light emitting structure and the heat transfer insulating layer.

According to the display device including the semiconductor light-emitting device according to the embodiment, the electrical contact characteristics are improved by expanding the electrical contact area by the side wiring connected to the side of the semiconductor light-emitting device, which has the technical effect of improving the lighting rate.

In addition, according to the embodiment, in the side wiring technology that connects the panel wiring to the side of the light emitting device chip after self-assembly using DEP force in the internal technology, the problem of disconnection of the side wiring at the bottom edge of the light emitting device chip can be solved.

For example, in the embodiment, the semiconductor light emitting device 150A may include a heat transfer insulating layer 157 disposed on the outside of the light emitting structure 152, and the side wiring 290 is disconnected by the heat transfer insulating layer 157. There is a technical effect of significantly increasing the lighting rate by preventing and improving electrical characteristics. For example, the embodiment includes a heat transfer insulating layer 157 disposed outside the light emitting structure 152 of the semiconductor light emitting device 150A, and solid electrodes of the first side wiring 290a and the second side wiring 290b. There is a special technical effect that can realize excellent contact characteristics (G) by forming a film.

In addition, according to the embodiment, even if an electrical connection defect occurs in the bonding process of the semiconductor light emitting device 150A, a highly reliable electrical connection is possible in an additional hot press process, thereby dramatically improving the lighting rate. there is.

For example, according to the embodiment, the heat generated by hot pressing is quickly transferred to the bottom edge of the semiconductor light emitting device by the heat transfer insulating layer 157 disposed around the outer circumference of the semiconductor light emitting device 150A, thereby reducing the heat of the material of the side electrode. There is a special technical effect of realizing excellent contact characteristics (G) by activating diffusion to form a solid electrode film of the first and second side wirings 290a and 290b.

For example, the side electrode may include a low-temperature metal material with a low melting point, such as Al, and the heat generated by hot pressing is quickly transferred to the bottom edge of the semiconductor light emitting device by the heat transfer insulating layer 157, thereby forming the side electrode. There is a special technical effect of realizing excellent contact characteristics (G) by activating heat diffusion of the material to form a solid electrode film of the first side wiring 290a and the second side wiring 290b.

In addition, according to the embodiment, a heat transfer insulating layer 157 is disposed around the outer circumference of the semiconductor light emitting device 150A, and a passivation layer is disposed between the light emitting structure 152 and the heat transfer insulating layer 157, thereby reducing the heat transfer insulating layer 157 in the hot press process. There is a technical effect of preventing deterioration of the electrical and characteristics of the light emitting structure 152 by preventing heat or pressure from being directly transmitted to the semiconductor light emitting device 150A.

In addition, according to the embodiment, when heat is generated during display implementation in a display device including a semiconductor light emitting device 150A, it can be diffused to the outside through the heat transfer insulating layer 157, thereby providing a technical effect that can improve the reliability of the display device. There is.

In addition, according to the embodiment, a heat transfer insulating layer 157 is disposed around the outer periphery of the semiconductor light emitting device 150A, and a part of the side electrode, for example, is placed not only on the light emitting structure 152 but also on the heat transfer insulating layer 157. By extending the first side wiring 290a, the bonding force between the first side wiring 290a and the heat transfer insulating layer 157 can be improved, thereby improving the reliability of the device.

For example, since the heat transfer insulating layer 157 includes the metal oxide constituting the side electrode, the bonding strength between the first side wiring 290a and the heat transfer insulating layer 157 can be significantly improved, thereby improving the reliability of the device. There is a technical effect.

In addition, according to the embodiment, the internal technology can solve the problem of the semiconductor light emitting device assembled in the assembly hole being separated due to weak fixing force between the semiconductor light emitting device and the dielectric layer on the assembly electrode.

For example, in the embodiment, the preliminary side wiring 290a has a special technical effect of stably fixing the semiconductor light emitting device 150A.

The technical effects of the embodiments are not limited to those described in this section, but include those understood from the description of the invention.

1 is an exemplary diagram of a living room of a house where a display device according to an embodiment is placed.

Figure 2 is a block diagram schematically showing a display device according to an embodiment.

FIG. 3 is a circuit diagram showing an example of the pixel of FIG. 2.

FIG. 4 is an enlarged view of the first panel area in the display device of FIG. 1.

FIG. 5 is a cross-sectional view taken along line B1-B2 in area A2 of FIG. 4.

Figure 6 is an example of a light emitting device according to an embodiment being assembled on a substrate by a self-assembly method.

Figure 7 is a partial enlarged view of area A3 in Figure 6.

Figure 8 is a photograph showing the disconnection of the side wiring in the internal technology.

Figure 9 is a cross-sectional view of a display device 300 including a semiconductor light-emitting device according to an embodiment.

FIG. 10 is a detailed cross-sectional view of a display device 300 including a semiconductor light emitting device according to the embodiment shown in FIG. 9.

FIG. 11 is an example photograph of the C1 area of the display device 300 including a semiconductor light emitting device according to the embodiment shown in FIG. 10.

Figures 12A to 12I are cross-sectional views of the manufacturing process of a display device 300 including a semiconductor light emitting device according to an embodiment.

Figure 13 is a cross-sectional view of a display device 300B including a semiconductor light emitting device according to a second embodiment.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. The suffixes 'module' and 'part' for components used in the following description are given or used interchangeably in consideration of ease of specification preparation, and do not have distinct meanings or roles in themselves. In addition, the attached drawings are intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings. Additionally, when an element such as a layer, region or substrate is referred to as being 'on' another component, this includes either directly on the other element or there may be other intermediate elements in between. do.

Display devices described in this specification include digital TVs, mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation, and slates. ) may include PCs, tablet PCs, ultra-books, desktop computers, etc. However, the configuration according to the embodiment described in this specification can be applied to a device capable of displaying even if it is a new product type that is developed in the future.

Hereinafter, a light emitting device according to an embodiment and a display device including the same will be described.

Hereinafter, a semiconductor light emitting device according to an embodiment and a display device including the same will be described.

FIG. 1 shows a living room of a house where a display device 100 according to an embodiment is installed.

The display device 100 of the embodiment can display the status of various electronic products such as a washing machine 101, a robot vacuum cleaner 102, and an air purifier 103, and can communicate with each electronic product based on IOT, and can communicate with the user. Each electronic product can also be controlled based on the setting data.

The display device 100 according to an embodiment may include a flexible display manufactured on a thin and flexible substrate. Flexible displays can bend or curl like paper while maintaining the characteristics of existing flat displays.

In a flexible display, visual information can be implemented by independently controlling the light emission of unit pixels arranged in a matrix form. A unit pixel refers to the minimum unit for implementing one color. A unit pixel of a flexible display can be implemented by a light-emitting device. In the embodiment, the light emitting device may be Micro-LED or Nano-LED, but is not limited thereto.

Next, FIG. 2 is a block diagram schematically showing a display device according to an embodiment, and FIG. 3 is a circuit diagram showing an example of the pixel of FIG. 2.

Referring to FIGS. 2 and 3 , a display device according to an embodiment may include a display panel 10, a driving circuit 20, a scan driver 30, and a power supply circuit 50.

The display device 100 of the embodiment may drive the light emitting device using an active matrix (AM) method or a passive matrix (PM) method.

The driving circuit 20 may include a data driver 21 and a timing control unit 22.

The display panel 10 may be divided into a display area (DA) and a non-display area (NDA) disposed around the display area (DA). The display area DA is an area where pixels PX are formed to display an image. The display panel 10 includes data lines (D1 to Dm, m is an integer greater than 2), scan lines (S1 to Sn, n is an integer greater than 2) that intersect the data lines (D1 to Dm), and a high potential voltage. It may include pixels (PX) connected to a high-potential voltage line supplied, a low-potential voltage line supplied with a low-potential voltage, and data lines (D1 to Dm) and scan lines (S1 to Sn).

Each of the pixels PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel (PX1) emits the first color light of the first wavelength, the second sub-pixel (PX2) emits the second color light of the second wavelength, and the third sub-pixel (PX3) emits the third color light. It is possible to emit light of a third color of wavelength. The first color light may be red light, the second color light may be green light, and the third color light may be blue light, but are not limited thereto. Additionally, in FIG. 2, it is illustrated that each of the pixels PX includes three sub-pixels, but the present invention is not limited thereto. That is, each pixel PX may include four or more sub-pixels.

Each of the first sub-pixel (PX1), the second sub-pixel (PX2), and the third sub-pixel (PX3) includes at least one of the data lines (D1 to Dm), at least one of the scan lines (S1 to Sn), and It can be connected to the above voltage line. As shown in FIG. 3 , the first sub-pixel PX1 may include light-emitting devices LD, a plurality of transistors for supplying current to the light-emitting devices LD, and at least one capacitor Cst.

Although not shown in the drawing, each of the first sub-pixel (PX1), the second sub-pixel (PX2), and the third sub-pixel (PX3) may include only one light emitting element (LD) and at least one capacitor (Cst). It may be possible.

Each of the light emitting elements LD may be a semiconductor light emitting diode including a first electrode, a plurality of conductive semiconductor layers, and a second electrode. Here, the first electrode may be an anode electrode and the second electrode may be a cathode electrode, but this is not limited.

Referring to FIG. 3, the plurality of transistors may include a driving transistor (DT) that supplies current to the light emitting devices (LD) and a scan transistor (ST) that supplies a data voltage to the gate electrode of the driving transistor (DT). . The driving transistor DT has a gate electrode connected to the source electrode of the scan transistor ST, a source electrode connected to a high potential voltage line to which a high potential voltage is applied, and a drain connected to the first electrodes of the light emitting elements LD. It may include electrodes. The scan transistor (ST) has a gate electrode connected to the scan line (Sk, k is an integer satisfying 1≤k≤n), a source electrode connected to the gate electrode of the driving transistor (DT), and a data line (Dj, j). It may include a drain electrode connected to an integer satisfying 1≤j≤m.

The capacitor Cst is formed between the gate electrode and the source electrode of the driving transistor DT. The storage capacitor Cst can charge the difference between the gate voltage and the source voltage of the driving transistor DT.

The driving transistor (DT) and the scan transistor (ST) may be formed of a thin film transistor. In addition, in FIG. 3, the driving transistor (DT) and the scan transistor (ST) are mainly described as being formed of a P-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but the present invention is not limited thereto. The driving transistor (DT) and scan transistor (ST) may be formed of an N-type MOSFET. In this case, the positions of the source and drain electrodes of the driving transistor (DT) and the scan transistor (ST) may be changed.

In addition, in FIG. 3, each of the first sub-pixel (PX1), the second sub-pixel (PX2), and the third sub-pixel (PX3) includes one driving transistor (DT), one scan transistor (ST), and one capacitor ( Although it is exemplified to include 2T1C (2 Transistor - 1 capacitor) with Cst), the present invention is not limited thereto. Each of the first sub-pixel (PX1), the second sub-pixel (PX2), and the third sub-pixel (PX3) may include a plurality of scan transistors (ST) and a plurality of capacitors (Cst).

Referring again to FIG. 2, the driving circuit 20 outputs signals and voltages for driving the display panel 10. To this end, the driving circuit 20 may include a data driver 21 and a timing control unit 22.

The data driver 21 receives digital video data (DATA) and source control signal (DCS) from the timing control unit 22. The data driver 21 converts digital video data (DATA) into analog data voltages according to the source control signal (DCS) and supplies them to the data lines (D1 to Dm) of the display panel 10.

The timing control unit 22 receives digital video data (DATA) and timing signals from the host system. Timing signals may include a vertical sync signal, a horizontal sync signal, a data enable signal, and a dot clock. The host system may be an application processor in a smartphone or tablet PC, a monitor, or a system-on-chip in a TV.

The scan driver 30 receives a scan control signal (SCS) from the timing controller 22. The scan driver 30 generates scan signals according to the scan control signal SCS and supplies them to the scan lines S1 to Sn of the display panel 10. The scan driver 30 may include a plurality of transistors and may be formed in the non-display area NDA of the display panel 10. Alternatively, the scan driver 30 may be formed as an integrated circuit, and in this case, it may be mounted on a gate flexible film attached to the other side of the display panel 10.

The power supply circuit 50 generates a high-potential voltage (VDD) and a low-potential voltage (VSS) for driving the light-emitting elements (LD) of the display panel 10 from the main power supply, thereby generating a high-potential voltage of the display panel 10. It can be supplied to lines and low-potential voltage lines. Additionally, the power supply circuit 50 may generate and supply driving voltages for driving the driving circuit 20 and the scan driver 30 from the main power source.

Next, Figure 4 is an enlarged view of the first panel area A1 in the display device of Figure 1.

Referring to FIG. 4 , the display device 100 of the embodiment may be manufactured by mechanically and electrically connecting a plurality of panel areas, such as the first panel area A1, by tiling.

The first panel area A1 may include a plurality of light emitting devices 150 arranged for each unit pixel (PX in FIG. 2).

For example, the unit pixel PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. For example, a plurality of red light-emitting devices 150R are disposed in the first sub-pixel (PX1), a plurality of green light-emitting devices 150G are disposed in the second sub-pixel PX2, and a plurality of blue light-emitting devices 150B may be placed in the third sub-pixel (PX3). The unit pixel PX may further include a fourth sub-pixel in which no light-emitting element is disposed, but this is not limited. Meanwhile, the light emitting device 150 may be a semiconductor light emitting device.

Next, Figure 5 is a cross-sectional view taken along line B1-B2 in area A2 of Figure 4.

Referring to FIG. 5, the display device 100 of the embodiment includes a substrate 200a, spaced apart wiring

lines

201a and 202a, a first insulating layer 211a, a second insulating layer 211b, and a third insulating layer ( 206) and a plurality of light emitting devices 150.

The wiring may include a first wiring 201a and a second wiring 202a that are spaced apart from each other. The first wiring 201a and the second wiring 202a may function as panel wiring for applying power to the light emitting device 150 from the panel, and in the case of self-assembly of the light emitting device 150, the dielectric for assembly It may also function as an assembled electrode to generate a phoretic force.

The

wirings

201a and 202a may be formed of transparent electrodes (ITO) or may contain a metal material with excellent electrical conductivity. For example, the

wirings

201a and 202a are titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), and molybdenum (Mo). It may be formed of at least one of these or an alloy thereof.

A first insulating layer 211a may be disposed between the first wiring 201a and the second wiring 202a, and a second insulating layer (211a) may be disposed on the first wiring 201a and the second wiring 202a. 211b) can be arranged. The first insulating layer 211a and the second insulating layer 211b may be an oxide film or a nitride film, but are not limited thereto.

The light-emitting device 150 may include a red light-emitting device 150R, a green light-emitting device 150G, and a blue light-emitting device 150B0 to form a unit pixel (sub-pixel), but is not limited thereto, and includes a red phosphor and Red and green colors can also be implemented by using green phosphors, etc.

The substrate 200a may be made of glass or polyimide. Additionally, the substrate 200a may include a flexible material such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate). Additionally, the substrate 200 may be made of a transparent material, but is not limited thereto. The substrate 200a may function as a support substrate in a panel, and may also function as an assembly substrate when self-assembling a light emitting device.

The third insulating layer 206 may include an insulating and flexible material such as polyimide, PEN, PET, etc., and may be integrated with the substrate 200a to form one substrate.

The third insulating layer 206 may be a conductive adhesive layer that has adhesiveness and conductivity, and the conductive adhesive layer is flexible and may enable a flexible function of the display device. For example, the third insulating layer 206 may be an anisotropic conductive film (ACF) or a conductive adhesive layer such as an anisotropic conductive medium or a solution containing conductive particles. The conductive adhesive layer may be a layer that is electrically conductive in a direction perpendicular to the thickness, but electrically insulating in a direction horizontal to the thickness.

The gap between the first and

second wirings

201a and 202a is formed to be smaller than the width of the light emitting device 150 and the width of the assembly hole 203H, so that the assembly position of the light emitting device 150 using an electric field can be fixed more precisely. can do.

A third insulating layer 206 is formed on the first and

second wirings

201a and 202a to protect the first and

second wirings

201a and 202a from the fluid 1200, and to protect the first and

second wirings

201a and 202a from the fluid 1200. Leakage of current flowing through 201a, 202a) can be prevented. The third insulating layer 206 may be formed as a single layer or multilayer of an inorganic insulator such as silica or alumina or an organic insulator.

Additionally, the third insulating layer 206 may include an insulating and flexible material such as polyimide, PEN, PET, etc., and may be integrated with the substrate 200 to form one substrate.

The third insulating layer 206 has a partition wall, and an assembly hole 203H can be formed by the partition wall. For example, the third insulating layer 206 may include an assembly hole 203H into which the light emitting device 150 is inserted (see FIG. 6). Therefore, during self-assembly, the light emitting device 150 can be easily inserted into the assembly hole 203H of the third insulating layer 206. The assembly hole 203H may be called an insertion hole, a fixing hole, an alignment hole, etc.

The assembly hole 203H may have a shape and size corresponding to the shape of the light emitting device 150 to be assembled at the corresponding location. Accordingly, it is possible to prevent another light emitting device from being assembled or a plurality of light emitting devices from being assembled into the assembly hole 203H.

Next, Figure 6 is a diagram showing an example in which a light emitting device according to an embodiment is assembled on a substrate by a self-assembly method, and Figure 7 is a partial enlarged view of area A3 in Figure 6. Figure 7 is a diagram with area A3 rotated by 180 degrees for convenience of explanation.

Based on FIGS. 6 and 7 , an example in which a semiconductor light emitting device according to an embodiment is assembled into a display panel by a self-assembly method using an electromagnetic field will be described.

The assembled substrate 200, which will be described later, can also function as the panel substrate 200a in a display device after assembly of the light emitting device, but the embodiment is not limited thereto.

Referring to FIG. 6, the semiconductor light-emitting device 150 may be introduced into the chamber 1300 filled with fluid 1200, and the semiconductor light-emitting device 150 may be placed on the assembly substrate ( 200). At this time, the light emitting device 150 adjacent to the assembly hole 203H of the assembly substrate 200 may be assembled into the assembly hole 230 by dielectrophoresis force generated by the electric field of the assembly electrodes. The fluid 1200 may be water such as ultrapure water, but is not limited thereto. The chamber may be called a water tank, container, vessel, etc.

After the semiconductor light emitting device 150 is input into the chamber 1300, the assembled substrate 200 may be placed on the chamber 1300. Depending on the embodiment, the assembled substrate 200 may be input into the chamber 1300.

Referring to FIG. 7, the semiconductor light emitting device 150 may be implemented as a vertical semiconductor light emitting device as shown, but is not limited to this and a horizontal light emitting device may be employed.

The semiconductor light emitting device 150 may include a magnetic layer (not shown) containing a magnetic material. The magnetic layer may include a magnetic metal such as nickel (Ni). Since the semiconductor light emitting device 150 introduced into the fluid includes a magnetic layer, it can move to the assembled substrate 200 by the magnetic field generated from the assembly device 1100. The magnetic layer may be disposed on the top, bottom, or both sides of the light emitting device.

The semiconductor light emitting device 150 may include a passivation layer 156 surrounding the top and side surfaces. The passivation layer 156 may be formed using an inorganic insulator such as silica or alumina through PECVD, LPCVD, sputtering deposition, etc. Additionally, the passivation layer 156 may be formed by spin coating an organic material such as photoresist or polymer material.

The semiconductor light emitting device 150 may include a first conductivity type semiconductor layer 152a, a second conductivity type semiconductor layer 152c, and an active layer 152b disposed between them. The first conductive semiconductor layer 152a may be an n-type semiconductor layer, and the second conductive semiconductor layer 152c may be a p-type semiconductor layer, but are not limited thereto.

A first electrode layer 154a may be disposed on the first conductivity type semiconductor layer 152a, and a second electrode layer 154b may be disposed on the second conductivity type semiconductor layer 152c. To this end, a partial area of the first conductivity type semiconductor layer 152a or the second conductivity type semiconductor layer 152c may be exposed to the outside. Accordingly, in the manufacturing process of the display device after the semiconductor light emitting device 150 is assembled on the assembly substrate 200, some areas of the passivation layer 156 may be etched.

The assembly substrate 200 may include a pair of first assembly electrodes 201 and second assembly electrodes 202 corresponding to each of the semiconductor light emitting devices 150 to be assembled. The first assembled electrode 201 and the second assembled electrode 202 can be formed by stacking multiple single metals, metal alloys, metal oxides, etc. For example, the first assembled electrode 201 and the second assembled electrode 202 include Cu, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. It may be formed including at least one of the following, but is not limited thereto.

In addition, the first assembled electrode 201 and the second assembled electrode 202 are made of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), and IGZO ( indium gallium zinc oxide), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO Nitride (IZON), Al-Ga ZnO (AGZO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ITO, but is not limited thereto.

The first assembled electrode 201 and the second assembled electrode 202 emit an electric field as an alternating voltage is applied, thereby fixing the semiconductor light emitting device 150 inserted into the assembly hole 203H by dielectrophoretic force. there is. The gap between the first assembly electrode 201 and the second assembly electrode 202 may be smaller than the width of the semiconductor light emitting device 150 and the width of the assembly hole 203H, and the semiconductor light emitting device 150 using an electric field may be smaller than the width of the assembly hole 203H. The assembly position can be fixed more precisely.

A first insulating layer 212 is formed on the first assembled electrode 201 and the second assembled electrode 202 to protect the first assembled electrode 201 and the second assembled electrode 202 from the fluid 1200. , leakage of current flowing through the first assembled electrode 201 and the second assembled electrode 202 can be prevented. For example, the first insulating layer 212 may be formed of a single layer or multiple layers of an inorganic insulator such as silica or alumina or an organic insulator. The first insulating layer 212 may have a minimum thickness to prevent damage to the first assembled electrode 201 and the second assembled electrode 202 when assembling the semiconductor light emitting device 150, and the semiconductor light emitting device ( 150) may have a maximum thickness for stable assembly.

A partition 207 may be formed on the first insulating layer 212. Some areas of the partition wall 207 may be located on top of the first assembled electrode 201 and the second assembled electrode 202, and the remaining area may be located on the top of the assembled substrate 200.

Meanwhile, when manufacturing the assembly substrate 200, some of the partition walls formed on the entire upper part of the first insulating layer 212 are removed, thereby forming assembly holes ( 203H) may be formed.

An assembly hole 203H in which the semiconductor light emitting devices 150 are coupled is formed in the assembly substrate 200, and the surface where the assembly hole 203H is formed may be in contact with the fluid 1200. The assembly hole 203H can guide the exact assembly position of the semiconductor light emitting device 150.

Meanwhile, the assembly hole 203H may have a shape and size corresponding to the shape of the semiconductor light emitting device 150 to be assembled at the corresponding location. Accordingly, it is possible to prevent another semiconductor light emitting device from being assembled or a plurality of semiconductor light emitting devices from being assembled into the assembly hole 203H.

Referring again to 6, after the assembled substrate 200 is placed in the chamber, the assembled device 1100 that applies a magnetic field may move along the assembled substrate 200. The assembly device 1100 may be a permanent magnet or an electromagnet.

The assembly device 1100 may move while in contact with the assembly substrate 200 in order to maximize the area to which the magnetic field is applied within the fluid 1200. Depending on the embodiment, the assembly device 1100 may include a plurality of magnetic materials or may include a magnetic material of a size corresponding to that of the assembly substrate 200. In this case, the moving distance of the assembly device 1100 may be limited to within a predetermined range.

The semiconductor light emitting device 150 in the chamber 1300 may move toward the assembly device 1100 and the assembly substrate 200 by the magnetic field generated by the assembly device 1100.

Referring to FIG. 7, while moving toward the assembly device 1100, the semiconductor light emitting device 150 enters the assembly hole 203H by the dielectrophoresis force (DEP force) formed by the electric field of the assembly electrode of the assembly substrate. It can be fixed.

Specifically, the first and

second assembly wirings

201 and 202 form an electric field using an AC power source, and a dielectrophoretic force may be formed between the

assembly wirings

201 and 202 by this electric field. The semiconductor light emitting device 150 can be fixed to the assembly hole 203H on the assembly substrate 200 by this dielectrophoretic force.

At this time, a predetermined solder layer (not shown) is formed between the light emitting device 150 assembled on the assembly hole 203H of the assembly substrate 200 and the assembly electrode, thereby improving the bonding strength of the light emitting device 150.

Additionally, after assembly, a molding layer (not shown) may be formed in the assembly hole 203H of the assembly substrate 200. The molding layer may be a transparent resin or a resin containing a reflective material or a scattering material.

By using the above-described self-assembly method using an electromagnetic field, the time required to assemble each semiconductor light-emitting device on a substrate can be drastically shortened, making it possible to implement a large-area, high-pixel display more quickly and economically.

According to undisclosed internal technology, DEP Force is required for self-assembly, but due to the difficulty in uniformly controlling the DEP Force, a problem occurs where the semiconductor light emitting device is tilted to an incorrect position within the assembly hall when assembling using self-assembly. There is.

In addition, due to the tilting phenomenon of the semiconductor light emitting device, the electrical contact characteristics are deteriorated in the subsequent electrical contact process, resulting in poor lighting rate and lower yield.

Internal technology is researching side contact wire technology that connects the panel wiring to the side of the LED chip to solve the problem of the semiconductor light emitting device being tilted after self-assembly by DEP Force. .

However, as shown in FIG. 8, there is a problem in which a disconnection (D) occurs where the wiring is broken at the bottom edge of the light emitting device chip during the side wiring process of the internal technology.

Specifically, the first side contact wire (SC1) formed on the side of the light emitting device chip (LED chip) and the second side contact wire (SC2) formed on the lower side of the light emitting device chip (LED chip) ), a disconnection (D) problem is occurring at the bottom edge, which is causing lighting defects.

In order to solve this problem of wire disconnection at the edge, internal technology conducted research to increase the thickness of the side contact wire by forming multiple side contact wires, but it was difficult to solve the problem of wire disconnection at the edge of the chip.

In addition, in order to solve the problem of disconnection at the edge, internal technology conducted research to remove the assembly barrier using O ₂ plasma before deposition of the side contact wire, but it took about 40 minutes or more to remove the assembly barrier. It takes time, and a reliability problem was discovered due to damage to the wiring of the assembled LED chip.

Meanwhile, in the internal technology, after assembly using DEP force, the process of draining the fluid in the water tank is carried out. If the power to the assembly electrode is cut off and there is no DEP force, the fixing force between the semiconductor light emitting device and the dielectric layer on the assembly electrode is weak, and the fluid is drained. The process takes tens of minutes or more, and there is a problem of the semiconductor light emitting device assembled in the assembly hole falling off.

To solve this problem, internal technology conducted research to fix the LED chip by using capillary phenomena to fill the space between the bottom of the LED chip and the lower assembly electrode with a chip-fixing organic film such as PR. However, there was a coating defect problem in the organic film coating process, and the chip separation problem was not completely solved.

FIG. 9 is a cross-sectional view of a display device 300 including a semiconductor light-emitting device according to an embodiment, and FIG. 10 is a detailed cross-sectional view of a display device 300 including a semiconductor light-emitting device according to an embodiment shown in FIG. 9 .

Referring to FIGS. 9 and 10 , a display device 300 including a semiconductor light emitting device according to an embodiment includes a substrate 200 and a first assembled electrode 201 arranged to be spaced apart from each other on the substrate 200. ), a second assembled electrode 202, a first insulating layer 212 disposed on the first assembled electrode 201 and the second assembled electrode 202, and a predetermined assembly hole 207H. and is electrically connected to the assembly partition 207 disposed on the first insulating layer 212, the semiconductor light emitting device 150A disposed in the assembly hole 207H, and the side of the semiconductor light emitting device 150A. It may include a side wiring 290 and a second panel electrode 320 electrically connected to the upper side of the semiconductor light emitting device 150A.

The semiconductor light emitting device 150A may include a light emitting structure 152, a lower electrode layer 154 disposed below the light emitting structure 152, and a heat transfer insulating layer 157 disposed outside the light emitting structure 152. there is. The semiconductor light emitting device 150A may further include a passivation layer (not shown) between the light emitting structure 152 and the heat transfer insulating layer 157.

Referring to FIG. 10, the light emitting structure 152 may include a first conductive semiconductor layer 152a, a second conductive semiconductor layer 152c, and an active layer 152b disposed between them. The first conductive semiconductor layer 152a may be an n-type semiconductor layer, and the second conductive semiconductor layer 152c may be a p-type semiconductor layer, but are not limited thereto.

The side wiring 290 may be electrically connected to the first conductive semiconductor layer 152a of the semiconductor light emitting device 150A. For example, the side wiring 290 may be electrically connected to the first conductive semiconductor layer 152a of the semiconductor light emitting device 150A through the lower electrode layer 154, but is not limited to this.

The side wiring 290 is in electrical contact with one or more of the first side wiring 290a and the first and

second assembly electrodes

201 and 202 disposed on the side of the semiconductor light emitting device 150A. It may include a second side wire 290b and a third side wire 290c in contact with the assembly partition 207.

The embodiment may include a first planarization layer 301 and a second planarization layer 302 disposed in the assembly hole 207H. The first planarization layer 301 and the second planarization layer 302 may be formed of an insulating material.

The first planarization layer 301 may be disposed within the side wiring 290.

The embodiment may include a second planarization layer 302 disposed on the first planarization layer 301 and the side wiring 290. The second planarization layer 302 is disposed between the side wiring 290 and the active layer 152b of the semiconductor light emitting device 150A to prevent electrical shorting and improve reliability.

Next, FIG. 11 is an example photograph of the C1 area of the display device 300 equipped with a semiconductor light emitting device according to the embodiment shown in FIG. 10.

In the embodiment, the semiconductor light emitting device 150A may include a heat transfer insulating layer 157 disposed on the outside of the light emitting structure 152, and the heat transfer insulating layer 157 prevents disconnection of the side wiring 290 and prevents electrical By improving the characteristics, there is a technical effect of significantly increasing the lighting rate.

For example, the embodiment includes a heat transfer insulating layer 157 disposed outside the light emitting structure 152 of the semiconductor light emitting device 150A, and solid electrodes of the first side wiring 290a and the second side wiring 290b. There is a special technical effect that can realize excellent contact characteristics (G) by forming a film.

According to the embodiment, even if an electrical connection defect occurs during the bonding process of the semiconductor light emitting device 150A, a highly reliable electrical connection is possible in an additional hot press process, thereby dramatically improving the lighting rate. .

Next, FIGS. 12A to 12I are cross-sectional views of the manufacturing process of the display device 300 including a semiconductor light emitting device according to an embodiment.

Referring to FIG. 12A, a display device 300 including a semiconductor light emitting device according to an embodiment includes a first assembled electrode 201 and a second assembled electrode 202 spaced apart from each other on an assembled substrate 200. It includes a first insulating layer 212 disposed between the first assembly electrode 201 and the second assembly electrode 202, and a predetermined assembly hole 207H, and is located on the first insulating layer 212. It may include an assembly partition 207 disposed, and a conductor light emitting device 150A disposed within the assembly hole 207H.

The semiconductor light emitting device 150A can be assembled by DEP force using the first assembly electrode 201 and the second assembly electrode 202.

Next, referring to FIG. 12B, a portion of the first insulating layer 212 in the assembly hole 207H is removed to expose the upper sides of the first assembly electrode 201 and the second assembly electrode 202. An insulating layer through hole ( H1) can be formed.

Next, referring to FIG. 12C, a preliminary side wiring layer 290a is formed on the exposed semiconductor light emitting device 150A, the assembled barrier rib 207, and the exposed first assembled electrode 201 and the second assembled electrode.

The preliminary side wiring 290a may be a metal layer or a conductive photosensitive material. For example, the preliminary side wiring 290a may be made of Al or Al alloy, but is not limited thereto. Additionally, the preliminary side wiring 290a may be Mo/Al/Mo or AuGe, but is not limited thereto.

Additionally, the preliminary side wiring 290a may be made of a conductive photosensitive material. For example, the preliminary side wiring 290a may include a conductive liquid photosensitive material. For example, the preliminary side wiring 290a may be formed by forming a conductive liquid photosensitive material and then performing exposure and development processes. The preliminary side wiring 290a may be a mixture of a conductive polymer and a photosensitive polymer, but is not limited thereto.

In the embodiment, the preliminary side wiring 290a has a special technical effect of stably fixing the semiconductor light emitting device 150A.

Accordingly, according to the embodiment, it is possible to solve the problem of the semiconductor light emitting device assembled in the assembly hole being separated due to weak fixing force between the semiconductor light emitting device and the dielectric layer on the assembly electrode in the internal technology.

Next, referring to FIG. 12D, a predetermined hot press process may be performed. Diffusion bonding of a metal material, for example, an Al material, in the preliminary side wiring 290a may be performed through the hot press process. The hot press process may range from 0.3 to 0.8 of the melting point, and the pressure may range from 0.04 to 0.1 Mpa. For example, the temperature of the hot press process may be in the range of about 200 to 250°C, but is not limited thereto.

According to the embodiment, even if an electrical connection defect occurs during the bonding process of the semiconductor light emitting device 150A, a highly reliable electrical connection can be made in an additional hot press process, thereby dramatically improving the lighting rate.

For example, according to the embodiment, a heat flow (HF) that quickly transfers heat by hot pressing to the bottom edge of the semiconductor light-emitting device 150A is provided by the heat transfer insulating layer 157 disposed around the outer circumference of the semiconductor light-emitting device 150A. By forming it, it can activate thermal diffusion of the material of the side electrode or cause electromigration between the interfaces.

This has a special technical effect of realizing excellent contact characteristics (G) by forming a solid electrode film of the first side wiring 290a and the second side wiring 290b.

For example, the embodiment includes a heat transfer insulating layer 157 disposed outside the light emitting structure 152 of the semiconductor light emitting device 150A, and solid electrodes of the first side wiring 290a and the second side wiring 290b. There is a special technical effect that can realize excellent contact characteristics by forming a film.

In addition, according to the embodiment, the heat transfer insulating layer 157 is disposed around the outer circumference of the semiconductor light emitting device 150A, so that heat or pressure in the hot press process is not directly transmitted to the semiconductor light emitting device 150A, thereby forming the light emitting structure 152. ) has a technical effect that can prevent deterioration of electrical and characteristics.

In addition, according to the embodiment, a heat transfer insulating layer 157 is disposed around the outer periphery of the semiconductor light emitting device 150A, and a part of the side electrode, for example, is placed not only on the light emitting structure 152 but also on the heat transfer insulating layer 157. By extending the first side wiring 290a (see FIG. 12g), the bonding force between the first side wiring 290a and the heat transfer insulating layer 157 can be improved, thereby improving the reliability of the device.

Next, referring to FIG. 12E, a first preliminary planarization layer 301a is formed on the preliminary side wiring 290a.

The first preliminary planarization layer 301a may be PAC (photo active compound) and may be formed of photoacryl, but is not limited thereto. In addition, the first preliminary planarization layer 301a may be a compound imparting photosensitivity to a binder resin such as an acrylic photosensitive resin, a Noblock resin, a polyimide, or a siloxane, but is not limited thereto.

Next, referring to FIG. 12F, the upper side of the first preliminary planarization layer 301a is partially removed to expose the upper and side surfaces of the preliminary side wiring 290a.

For example, a portion of the upper side of the first preliminary planarization layer 301a is removed by dry etching to expose the position of the first conductive semiconductor layer 152a of the semiconductor light emitting device 150A, thereby forming a first planarization layer ( 301) can be formed.

Next, referring to FIG. 12g, the exposed preliminary side wiring 290a can be removed to form the side wiring 290.

second assembly electrodes

Next, referring to FIG. 12H, a second planarization layer 302 may be formed on the semiconductor light emitting device 150A and the assembly partition 207. The second planarization layer 302 is also disposed between the side wiring 290 and the active layer 152b of the semiconductor light emitting device 150A to prevent electrical short circuit and improve reliability.

Thereafter, a third through hole 302H is formed by removing a portion of the second planarization layer 302, thereby opening a portion of the upper surface of the semiconductor light emitting device 150A.

Referring to FIG. 12i, a second panel electrode 320 electrically connected to the top surface of the semiconductor light emitting device 150A can be formed.

Next, Figure 13 is a cross-sectional view of a display device 300B including a semiconductor light emitting device according to the second embodiment.

The second embodiment may adopt the technical features of the previously described embodiment.

For example, the display device 300B including a semiconductor light emitting device according to the second embodiment includes a substrate 200, a first assembled electrode 201 spaced apart from each other on the

substrate

200, and 2. It includes an assembled electrode 202, a first insulating layer 212 disposed on the first assembled electrode 201 and the second assembled electrode 202, and a predetermined assembly hole 207H. 1 An assembly partition wall 207 disposed on the insulating layer 212, a semiconductor light emitting device 150A disposed in the assembly hole 207H, and a side wiring electrically connected to the side of the semiconductor light emitting device 150A. It may include 290 and a second panel electrode 320 electrically connected to the upper side of the semiconductor light emitting device 150A.

The semiconductor light emitting device 150A includes a light emitting structure 152, a lower electrode layer 154 disposed below the light emitting structure 152, and a second heat transfer insulating layer 157B disposed outside the light emitting structure 152. can do. The semiconductor light emitting device 150A may further include a passivation layer (not shown) between the light emitting structure 152 and the heat transfer insulating layer 157.

second assembly electrodes

The description below will focus on the main features of the second embodiment.

The second embodiment includes a second heat transfer insulating layer 157B disposed on the outside of the light emitting structure 152, and the lower end of the second heat transfer insulating layer 157B is arranged to extend to the bottom of the light emitting structure 152. You can.

Accordingly, the heat transfer efficiency of the second heat transfer insulating layer 157B can be efficiently transmitted to the lower edge of the semiconductor light emitting device where the first side wiring 290a and the second side wiring 290b meet.

For example, according to the second embodiment, the heat generated by hot pressing is quickly transferred to the bottom edge of the semiconductor light emitting device by the second heat transfer insulating layer 157B, thereby activating heat diffusion of the material of the side electrode. There is a special technical effect of realizing better contact characteristics by forming a solid electrode film of the first side wiring 290a and the second side wiring 290b.

The above detailed description should not be construed as restrictive in any respect and should be considered illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiments are included in the scope of the embodiments.

Embodiments may be adopted in the field of displays that display images or information.

Embodiments can be adopted in the field of displays that display images or information using semiconductor light-emitting devices.

Embodiments can be adopted in the field of displays that display images or information using micro- or nano-level semiconductor light-emitting devices.

Claims

Board;

a first electrode and a second electrode arranged to be spaced apart from each other on the substrate;

a first insulating layer disposed on the first and second electrodes;

an assembly partition including a predetermined assembly hole and disposed on the first insulating layer;

a semiconductor light emitting device disposed in the assembly hole;

It includes a side wiring electrically connected to the side of the semiconductor light-emitting device and a second panel electrode electrically connected to the top of the semiconductor light-emitting device,

A display device including a semiconductor light emitting device, wherein the semiconductor light emitting device includes a light emitting structure and a heat transfer insulating layer disposed on the outside of the light emitting structure.
According to paragraph 1,

The light emitting structure includes a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between them,

A display device including a semiconductor light-emitting device, wherein the side wiring is electrically connected to a first conductive semiconductor layer of the semiconductor light-emitting device.
According to paragraph 1,

The side wiring is

a first side wiring disposed on a side of the semiconductor light emitting device; and

A display device including a semiconductor light emitting device; a second side wiring electrically contacting one or more of the first and second electrodes.
According to paragraph 1,

It further includes a passivation layer disposed between the light emitting structure and the heat transfer insulating layer,

A display device including a semiconductor light emitting device, wherein the heat transfer efficiency of the passivation layer is lower than that of the heat transfer insulating layer.
According to paragraph 1,

The side wiring is

A display device including a semiconductor light emitting device disposed on a side of the light emitting structure and the heat transfer insulating layer.
Board;

a first electrode and a second electrode arranged to be spaced apart from each other on the substrate;

a first insulating layer disposed on the first and second electrodes;

an assembly partition including a predetermined assembly hole and disposed on the first insulating layer; and

It includes a semiconductor light emitting device disposed in the assembly hole,

The semiconductor light emitting device includes a light emitting structure and a heat transfer insulating layer disposed on the outside of the light emitting structure,

A display device including a semiconductor light-emitting device, wherein the bottom of the heat transfer insulating layer extends to the bottom of the light-emitting structure.
According to clause 6,

The light emitting structure includes a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between them,

A display device including a semiconductor light-emitting device, wherein the side wiring is electrically connected to a first conductive semiconductor layer of the semiconductor light-emitting device.
According to clause 6,

The side wiring is

a first side wiring disposed on a side of the semiconductor light emitting device; and

A display device including a semiconductor light emitting device; a second side wiring electrically contacting one or more of the first and second electrodes.
According to clause 6,

It further includes a passivation layer disposed between the light emitting structure and the heat transfer insulating layer,

A display device including a semiconductor light emitting device, wherein the heat transfer efficiency of the passivation layer is lower than that of the heat transfer insulating layer.
According to clause 6,

The side wiring is

A display device including a semiconductor light emitting device disposed on a side of the light emitting structure and the heat transfer insulating layer.