Light-emitting element transfer system and method for transferring light-emitting elements

Abstract

This provides technology related to a light-emitting element transfer system. [Solution] One embodiment of this specification relates to a light-emitting element transfer system and a transfer method, the light-emitting element transfer system includes a vacuum chamber which creates or destroys a vacuum atmosphere inside, an alignment unit which is located inside the vacuum chamber adjacent to the loading unit and aligns a first substrate and a second substrate, a bonding unit which is located inside the vacuum chamber adjacent to the alignment unit and applies heat and pressure to the aligned first substrate and second substrate, and a first transport unit which is located inside the vacuum chamber so as to be movable in a first or second direction and transports the first substrate or the second substrate to the alignment unit and the first substrate and second substrate which have been aligned in the alignment unit to the bonding unit.

Description

Technical Field

[0001] The present invention relates to a light-emitting element transfer system and a transfer method.

Background Art

[0002] Display devices are becoming increasingly important with the development of multimedia. Accordingly, various types of display devices such as organic light-emitting display devices (OLEDs) and liquid crystal display devices (LCDs) are being used.

[0003] A display device for displaying an image includes a display panel such as a light-emitting display panel or a liquid crystal display panel. Among them, the light-emitting display panel can include a light-emitting diode (LED), and the light-emitting diode includes an organic light-emitting diode that uses an organic substance as a fluorescent substance, or an inorganic light-emitting diode that uses an inorganic substance as a fluorescent substance.

[0004] When manufacturing a display panel that uses an inorganic light-emitting diode as a light-emitting diode, it is necessary to develop transfer equipment for transferring micro LEDs (Micro LED) onto the substrate of the display panel.

Prior Art Documents

Patent Documents

[0005]

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to provide a light-emitting element transfer system capable of performing an accurate alignment process and a bonding process in the same chamber.

[0007] The problems addressed by the present invention are not limited to those described above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0008] A light-emitting element transfer system according to one embodiment for solving the above-mentioned problems may include a vacuum chamber that creates or destroys a vacuum atmosphere inside, an alignment unit that aligns a first substrate and a second substrate inside the vacuum chamber, a bonding unit that is located adjacent to the alignment unit inside the vacuum chamber and applies heat and pressure to the aligned first and second substrates, and a first transport unit that is located within the vacuum chamber so as to be movable in a first or second direction and transports the first substrate or the second substrate to the alignment unit and the first and second substrates that have been aligned in the alignment unit to the bonding unit.

[0009] The alignment unit may include a stage module that supports the first substrate during the alignment process, a holding member positioned above the stage module and adsorbing or gripping the back surface of the second substrate to support the second substrate on top of the first substrate, a second drive member that moves the holding member on a single plane, and a vision member that captures the alignment of the first and second substrates.

[0010] The stage module may be a UVW stage, and the first transport unit may be a vacuum robot.

[0011] The vacuum robot may include a dual arm.

[0012] The bonding portion may include a stage including a holding mechanism, a protruding member and a heater, a lifting member for raising and lowering the stage vertically, a pressing member disposed on the stage for pressing a substrate placed on the stage and transmitting laser light, and a laser member located above the pressing member for emitting laser light onto the substrate placed on the stage.

[0013] The light-emitting element transfer system may further include a loading section located inside a vacuum chamber into which a substrate or tray is loaded.

[0014] The loading section may further include a first loading section into which a first substrate or a first tray containing the first substrate is loaded, and a second loading section into which a second tray containing a second substrate is loaded.

[0015] The vacuum chamber includes a chamber door located on one side, and a tray on which a first substrate or a second substrate is placed can enter and exit the vacuum chamber through the chamber door.

[0016] The light-emitting element transfer system may further include a cassette located outside the vacuum chamber for loading trays on which a first substrate or a second substrate is placed, and a second transport unit located outside the vacuum chamber for transporting the trays loaded on the cassette into the vacuum chamber.

[0017] The light-emitting element transfer system may include a vacuum chamber that creates or breaks a vacuum atmosphere inside, an alignment unit that aligns a first substrate and a second substrate inside the vacuum chamber, a bonding unit located adjacent to the alignment unit inside the vacuum chamber and that applies heat and pressure to the aligned first and second substrates, and a stage module that is movably arranged between the alignment unit and the bonding unit and includes a stage including a heater and a stage driving member that drives the stage.

[0018] The stage may further include a holding mechanism on its upper surface for preventing movement of the substrate or tray, and a protruding member that can be extended and retracted.

[0019] The alignment unit may include a holding member positioned on top of the stage module that adsorbs or grips the back surface of the second substrate to support the second substrate on top of the first substrate, a second driving member that moves the holding member on a single plane, and a vision member that captures the alignment of the first and second substrates.

[0020] The bonding portion may include a pressure plate that transmits laser light, a support portion that supports the pressure plate, a pressure drive portion that raises and lowers the pressure plate vertically, a window that overlaps with the pressure plate, transmits laser light, and is positioned on the ceiling of the vacuum chamber, and a laser member that emits laser light from the top of the window.

[0021] The stage module may further include a first lifting member for raising and lowering the stage vertically.

[0022] The alignment portion may further include a second lifting member that moves the holding member up and down in the vertical direction.

[0023] The light-emitting element transfer method may include the steps of: a second transport unit loading a first tray on which a first substrate is placed and a second tray on which a second substrate is placed into a vacuum chamber; creating a vacuum inside the vacuum chamber; the first transport unit transporting the first tray and the second tray to an alignment unit; the alignment unit aligning and bonding a plurality of second substrates placed on the second tray to the first substrate placed on the first tray one by one; the first transport unit transporting the first tray on which the first substrate bonded to the second substrate is placed to a bonding unit; the bonding unit applying heat and pressure to the first substrate bonded to the second substrate to bond the light-emitting elements arranged on the first substrate and the second substrate; and breaking the vacuum atmosphere inside the vacuum chamber.

[0024] The step of conveying to the alignment unit may include placing the first tray on the UVW stage of the alignment unit and adsorbing or gripping one of the plurality of second substrates placed on the second tray with a holding member.

[0025] The step of aligning and attaching may include adsorbing the first tray using a holding mechanism on the upper surface of the UVW stage, moving the UVW stage while lowering the holding member to align the first tray and the second tray, and the step in which the second holding member interrupts the adsorption or gripping of the second substrate and attaches the second substrate onto the first substrate.

[0026] The light-emitting element transfer method may include a step in which a second transfer unit loads a first substrate and a second tray on which a plurality of second substrates are placed into a vacuum chamber, a step of evacuating the inside of the vacuum chamber, a step in which a first transfer unit conveys the first substrate and the second tray to an alignment unit, a step of aligning and attaching one by one the plurality of second substrates placed on the second tray to the first substrate in the alignment unit, a step in which the first transfer unit conveys the first substrate attached with the second substrate to a bonding unit, a step of applying heat and pressure to the first substrate attached with the second substrate in the bonding unit to bond the light-emitting elements disposed on the first substrate and the second substrate, and a step of breaking the vacuum atmosphere inside the vacuum chamber.

[0027] The light-emitting element transfer method may include the steps of: a second transfer unit loading a first tray on which a first substrate is placed and a second tray on which a plurality of second substrates are placed onto a stage module in a vacuum chamber; evacuating the interior of the vacuum chamber; the stage module moving the stage to an alignment area; a holding member of an alignment unit adsorbing or gripping any one of the plurality of second substrates placed on the second tray; the holding member of the alignment unit adsorbing or gripping the plurality of second substrates placed on the second tray one by one, moving to the alignment area, and aligning and attaching the second substrate onto the first substrate; the stage module transporting the stage to a bonding area; applying heat and pressure to the first substrate attached to the second substrate in the bonding area to bond the light-emitting elements disposed on the first substrate and the second substrate; and destroying the vacuum atmosphere inside the vacuum chamber.

[0028] In the bonding step, the stage may generate heat from a built-in heater, the bonding unit may irradiate the first substrate with a laser, and a pressing member may be lowered to apply pressure onto the first substrate attached to the second substrate.

Advantages of the Invention

[0029] According to one embodiment, the light-emitting element transfer system can continuously perform an alignment process and a bonding process in a high-vacuum environment without opening the vacuum chamber, thereby improving the production efficiency of the transfer device.

[0030] Also, since the alignment process and the bonding process can be performed in a high-vacuum environment, penetration of moisture or oxygen into the light-emitting elements of the target substrate can be minimized. Therefore, the element reliability of the target substrate, i.e., the display device, can be improved.

[0031] The effects according to the embodiment are not limited to the contents exemplified above, and more diverse effects are included in this specification.

Brief Description of the Drawings

[0032] [Figure 1] This is a layout diagram showing a display device according to one embodiment. [Figure 2] This is an illustrative diagram showing an example of a pixel in Figure 1. [Figure 3] This is an illustrative diagram showing yet another example of a pixel in Figure 1. [Figure 4] This is a cross-sectional view showing an example of a display panel cut along line A-A' in Figure 2. [Figure 5] This is a schematic plan view illustrating a light-emitting element transfer system according to one embodiment. [Figure 6] This is a schematic side view showing a light-emitting element transfer system according to one embodiment. [Figure 7] This is an enlarged view of the loading section according to the embodiments shown in Figures 5 and 6. [Figure 8] This is an enlarged view of the loading section according to the embodiments shown in Figures 5 and 6. [Figure 9] Figures 7 and 8 show enlarged views of the loading section according to other embodiments. [Figure 10] Figures 7 and 8 show enlarged views of the loading section according to other embodiments. [Figure 11] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 12] Figure 11 is a side view of the light-emitting element transfer system. [Figure 13] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 14] Figure 13 is a side view of the light-emitting element transfer system. [Figure 15] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 16] Figure 15 is a side view of the light-emitting element transfer system. [Figure 17] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 18]Figure 17 is a side view of the light-emitting element transfer system. [Figure 19] This is a perspective view illustrating the configuration of the first transport unit. [Figure 20] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 21] Figure 20 is a side view of the light-emitting element transfer system. [Figure 22] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 23] Figure 22 is a side view of the light-emitting element transfer system. [Figure 24] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 25] Figure 24 is a side view of the light-emitting element transfer system. [Figure 26] This is a schematic plan view illustrating a light-emitting element transfer system according to another embodiment. [Figure 27] Figure 26 is a side view of the light-emitting element transfer system. [Figure 28] This is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment. [Figure 29] This is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment. [Figure 30] This is an illustrative diagram showing a smartwatch including a display device according to one embodiment. [Figure 31] This is an illustrative diagram showing a virtual reality device including a display device according to one embodiment. [Figure 32] This is an illustrative diagram showing a virtual reality device including a display device according to one embodiment. [Figure 33] This is an illustrative diagram showing a virtual reality device including a display device according to another embodiment. [Figure 34] This is an illustrative diagram showing the instrument panel and center fascia of a vehicle including a display device according to one embodiment. [Figure 35] This is an illustrative diagram showing a transparent display device including a display device according to one embodiment. [Modes for carrying out the invention]

[0033] The advantages and features of the present invention, as well as methods for achieving them, will become clearer with reference to the embodiments described below in detail, along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be realized in a variety of different forms, and these embodiments are provided merely to complete the disclosure of the present invention and to fully inform those who are ordinary skill in the art to which the invention pertains, of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0034] When an element or layer is referred to as "on" another element or layer, this includes all cases where the other layer or other element is interposed immediately above or between the other element. Throughout the specification, the same reference numerals refer to the same component. The shapes, sizes, proportions, angles, numbers, etc., shown in the drawings illustrating embodiments are illustrative and the invention is not limited to those shown.

[0035] The following describes specific embodiments with reference to the attached drawings.

[0036] Figure 1 is a layout diagram showing a display device according to one embodiment. Figure 2 is an illustrative diagram showing an example of the pixels in Figure 1. Figure 3 is an illustrative diagram showing yet another example of the pixels in Figure 1.

[0037] Referring to Figures 1 to 3, a display device is a device that displays videos and still images, and can be used as a display screen for a variety of products, including not only portable electronic devices such as mobile phones, smartphones, tablet PCs, smartwatches, watch phones, mobile communication terminals, electronic organizers, e-books, PMPs (portable multimedia players), navigation systems, and UMPCs (Ultra Mobile PCs), but also televisions, laptops, monitors, billboards, and the Internet of Things (IoT).

[0038] The display device 100 can be formed as a rectangular plane having a long side in a first direction DR1 and a short side in a second direction DR2 intersecting the first direction DR1. The corner where the long side in the first direction DR1 and the short side in the second direction DR2 intersect can be formed rounded or at a right angle with a predetermined curvature. The planar shape of the display device 100 is not limited to a rectangle, but can be formed as other polygons, circles, or ellipses. The display device 100 is formed as a flat surface, but is not limited to this. For example, the display device 100 may include curved surfaces formed at its left and right ends that have a constant curvature or a changing curvature. The display device 100 can also be formed to be flexible so that it can be bent, warped, folded, or rolled up.

[0039] The display device 100 may further include pixels PX for displaying an image, scan wiring extending in a first direction DR1, and data wiring extending in a second direction DR2. The pixels PX may be arranged in a matrix in the first direction DR1 and the second direction DR2.

[0040] Each pixel PX may contain multiple sub-pixels RP, GP, and BP, as shown in Figures 2 and 3. While Figures 2 and 3 show that each pixel PX contains three sub-pixels RP, GP, and BP, namely a first sub-pixel RP, a second sub-pixel GP, and a third sub-pixel BP, the embodiments described herein are not limited to this.

[0041] The first subpixel RP, the second subpixel GP, and the third subpixel BP may be connected to any one of the data lines and at least one of the scan lines.

[0042] Each of the first subpixel RP, second subpixel GP, and third subpixel BP can have a rectangular, square, or rhombus-shaped planar shape. For example, each of the first subpixel RP, second subpixel GP, and third subpixel BP can have a rectangular planar shape with a short side in the first direction DR1 and a long side in the second direction DR2, as shown in Figure 2. Alternatively, each of the first subpixel RP, second subpixel GP, and third subpixel BP can have a square or rhombus-shaped planar shape with sides of the same length in the first direction DR1 and the second direction DR2, as shown in Figure 3.

[0043] As shown in Figure 2, the first subpixel RP, the second subpixel GP, and the third subpixel BP may be arranged in the first direction DR1. Alternatively, either the second subpixel GP or the third subpixel BP and the first subpixel RP may be arranged in the first direction DR1, and the remaining one and the first subpixel RP may be arranged in the second direction DR2. For example, as shown in Figure 3, the first subpixel RP and the second subpixel GP may be arranged in the first direction DR1, and the first subpixel RP and the third subpixel BP may be arranged in the second direction DR2.

[0044] Alternatively, either the first subpixel RP or the third subpixel BP and the second subpixel GP may be arranged in the first direction DR1, and the remaining one and the second subpixel GP may be arranged in the second direction DR2. Alternatively, either the first subpixel RP or the second subpixel GP and the third subpixel BP may be arranged in the first direction DR1, and the remaining one and the third subpixel BP may be arranged in the second direction DR2.

[0045] A first subpixel RP may include a first light-emitting element that emits first light, a second subpixel GP may include a second light-emitting element that emits second light, and a third subpixel BP may include a third light-emitting element that emits third light. Here, the first light may be light in the red wavelength band, the second light in the green wavelength band, and the third light in the blue wavelength band. The red wavelength band is generally in the 600nm to 750nm range, the green wavelength band is generally in the 480nm to 560nm range, and the blue wavelength band is generally in the 370nm to 460nm range, but the embodiments described herein are not limited thereto.

[0046] Each of the first subpixel RP, second subpixel GP, and third subpixel BP may include an inorganic light-emitting element having an inorganic semiconductor as a light-emitting element. For example, the inorganic light-emitting element may be a flip-chip type microLED (Light Emitting Diode), but the embodiments herein are not limited thereto.

[0047] As shown in Figures 2 and 3, the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may be substantially identical, but the embodiments herein are not limited thereto. At least one of the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may differ from the other one. Alternatively, two of the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may be substantially identical, and the remaining one may differ from the other two. Alternatively, the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may differ from each other.

[0048] Figure 4 is a cross-sectional view showing an example of a display panel cut along line A-A' in Figure 2.

[0049] Referring to Figure 4, the display device 100 may include a thin-film transistor layer TFTL and a light-emitting element LE arranged on a substrate SUB. The thin-film transistor layer TFTL may be a layer on which thin-film transistors (TFTs) are formed.

[0050] The thin-film transistor layer TFTL includes an active layer ACT, a first gate layer GTL1, a second gate layer GTL2, a first data metal layer DTL1, a second data metal layer DTL2, a third data metal layer DTL3, and a fourth data metal layer DTL4. The thin-film transistor layer TFTL also includes a buffer film BF, a gate insulating film 130, a first interlayer insulating film 141, a second interlayer insulating film 142, a first planarization film 160, a first insulating film 161, a second planarization film 180, and a second insulating film 181.

[0051] The substrate SUB may be a base substrate or base member for supporting a display device. The substrate SUB may be a rigid substrate made of glass material, but the embodiments herein are not limited thereto. The substrate SUB may be a flexible substrate that can be bent, folded, rolled, etc. In this case, the substrate SUB may contain an insulating material such as a polymer resin such as polyimide (PI).

[0052] A buffer film BF is placed on one surface of the substrate SUB. The buffer film BF may be a film that prevents the penetration of air or moisture. The buffer film BF consists of multiple inorganic films that are alternately stacked. For example, the buffer film BF can be formed as a multilayer film in which one or more inorganic films from among silicon nitride layers, silicon oxynitride layers, silicon oxide layers, titanium oxide layers, and aluminum oxide layers are alternately stacked. The buffer film BF may be omitted.

[0053] An active layer ACT is placed on the buffer film BF. The active layer ACT may contain a silicon semiconductor such as polycrystalline silicon, single-crystal silicon, low-temperature polycrystalline silicon, and amorphous silicon, or an oxide semiconductor.

[0054] The active layer ACT may include the channel TCH, first electrode TS, and second electrode TD of the thin-film transistor TFT. The channel TCH of the thin-film transistor TFT may be a region that overlaps with the gate electrode TG of the thin-film transistor TFT in a third direction DR3, which is the thickness direction of the substrate SUB. The first electrode TS of the thin-film transistor TFT may be located on one side of the channel TCH, and the second electrode TD may be located on the other side of the channel TCH. The first electrode TS and the second electrode TD of the thin-film transistor TFT may be regions that do not overlap with the gate electrode TG in the third direction DR3. The first electrode TS and the second electrode TD of the thin-film transistor TFT may be conductive regions in which ions are doped into a silicon semiconductor or oxide semiconductor.

[0055] A gate insulating film 130 is placed on the active layer ACT. The gate insulating film 130 can be formed from an inorganic film, such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0056] A first gate layer GTL1 is placed on the gate insulating film 130. The first gate layer GTL1 may include the gate electrode TG of the thin-film transistor TFT and the first capacitor electrode CAE1 of the capacitor Cst. The first gate layer GTL1 can be formed as a single or multilayer from one of the following materials or alloys: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0057] A first interlayer insulating film 141 is placed on the first gate layer GTL1. The first interlayer insulating film 141 can be formed from an inorganic film, such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0058] A second gate layer GTL2 is placed on the first interlayer insulating film 141. The second gate layer GTL2 may include a second capacitor electrode CAE2 of the capacitor Cst. The second gate layer GTL2 can be formed as a single or multilayer structure consisting of one of the following materials or an alloy thereof: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0059] A second interlayer insulating film 142 is placed on the second gate layer GTL2. The second interlayer insulating film 142 can be formed from an inorganic film, such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0060] A first data metal layer DTL1, including a first connecting electrode CE1, a first sub-pad, and data wiring, is disposed on the second interlayer insulating film 142. The data wiring is formed integrally with the first sub-pad, but the embodiments herein are not limited thereto. The first data metal layer DTL1 can be formed as a single or multilayer of one or an alloy thereof of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0061] The first connecting electrode CE1 can be connected to the first electrode TS or second electrode TD of the thin-film transistor TFT via a first contact hole CT1 that penetrates the gate insulating film 130, the first interlayer insulating film 141, and the second interlayer insulating film 142.

[0062] An active layer ACT, a first gate layer GTL1, a second gate layer GTL2, and a first planarization film 160 for flattening the step created by the first data metal layer DTL1 are arranged on the first data metal layer DTL1. The first planarization film 160 can be formed from an organic film such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0063] A first insulating film 161 and a second data metal layer DTL2 are arranged on the first planarization film 160. The second data metal layer DTL2 may include a second connecting electrode CE2 and a second sub-pad PD2. The second connecting electrode CE2 may be connected to the first connecting electrode CE1 via a second contact hole CT2 that penetrates the first insulating film 161 and the first planarization film 160. The second data metal layer DTL2 can be formed as a single or multilayer from one of the following materials or an alloy thereof: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0064] A second planarization film 180 is placed on the second data metal layer DTL2. The second planarization film 180 can be formed from an organic film such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0065] A second insulating film 181 and a third data metal layer DTL3 are arranged on the second planarization film 180. The third data metal layer DTL3 may include a third connecting electrode CE3 and a third sub-pad. The third connecting electrode CE3 may be connected to the second connecting electrode CE2 via a third contact hole CT3 that penetrates the second insulating film 181 and the second planarization film 180. The third data metal layer DTL3 can be formed as a single or multilayer from one of the following: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof.

[0066] A third planarization film 190 is placed on the third data metal layer DTL3. The third planarization film 190 can be formed from an organic film such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0067] A fourth data metal layer DTL4 is disposed on the third planarization film 190. The fourth data metal layer DTL4 may include an anode pad electrode APD, a cathode pad electrode CPD, and a fourth sub-pad. The anode pad electrode APD may be connected to a third connecting electrode CE3 via a fourth contact hole CT4 that penetrates the third planarization film 190. The cathode pad electrode CPD may be supplied with a first power supply voltage, which is a low potential voltage. The fourth data metal layer DTL4 can be formed as a single or multilayer of one or an alloy thereof of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0068] The light-emitting element LE is exemplified as a flip-chip type microLED in which the first contact electrode CTE1 and the second contact electrode CTE2 are arranged to face the anode pad electrode APD and the cathode pad electrode CPD, but is not limited to this. The light-emitting element LE may be an inorganic light-emitting element made of an inorganic material such as GaN. The lengths of the first direction DR1, the second direction DR2, and the third direction DR3 of the light-emitting element LE may each be several to several hundred μm. For example, the lengths of the first direction DR1, the second direction DR2, and the third direction DR3 of the light-emitting element LE may each be approximately 100 μm or less. Also, for example, each subpixel may be an organic light-emitting element or a liquid crystal element.

[0069] Light-emitting elements (LEs) can be formed by growing on a semiconductor substrate such as a silicon wafer. Each light-emitting element (LE) can be transferred directly from the silicon wafer onto the anode pad electrode (APD) and cathode pad electrode (CPD) of the substrate (SUB). In this case, the first contact electrode (CTE1) and the anode pad electrode (APD) can be bonded to each other by a bonding process. The second contact electrode (CTE2) and the cathode pad electrode (CPD) can also be bonded to each other by a bonding process. The first contact electrode (CTE1) and the anode pad electrode (APD) can be electrically connected to each other via a bonding electrode (23). The second contact electrode (CTE2) and the cathode pad electrode (CPD) can also be electrically connected to each other via the bonding electrode (23).

[0070] As an example, a bonding electrode 23 is placed on one surface of the light-emitting element LE. The bonding electrode 23 may be a bond formed by laser-assisted pressure fusion bonding. Here, pressure fusion bonding refers to a state in which the bonding electrode 23 is heated and melted, and the light-emitting element LE, the anode pad electrode APD, and the cathode pad electrode CPD are melted and mixed together, and then cooled and solidified when the laser supply is terminated. Even as the fused and mixed state cools and solidifies, the conductivity of the light-emitting element LE, the anode pad electrode APD, and the cathode pad electrode CPD is maintained, so the anode pad electrode APD and the cathode pad electrode CPD can be electrically connected to the light-emitting element LE, and also physically connected. Therefore, the bonding electrode 23 can be placed on the first contact electrode CTE1 and the second contact electrode CTE2 of the light-emitting element LE.

[0071] The junction electrode 23 may include, for example, Au, AuSn, PdIn, InSn, NiSn, Au-Au, AgIn, AgSn, Al, Ag, or carbon nanotubes (CNTs). These can be used individually or in combination of two or more.

[0072] Each of the light-emitting elements (LEs) may be a light-emitting structure comprising a base substrate (SPUB), an n-type semiconductor (NSEM), an active layer (MQW), a p-type semiconductor (PSEM), a first contact electrode (CTE1), and a second contact electrode (CTE2).

[0073] The base substrate SPUB may be a sapphire substrate, but the embodiments described herein are not limited thereto.

[0074] An n-type semiconductor NSEM is placed on one surface of a base substrate SPUB. For example, an n-type semiconductor NSEM is placed on the bottom surface of a base substrate SPUB. An n-type semiconductor NSEM consists of GaN doped with n-type conductive dopants such as Si, Ge, and Sn.

[0075] The active layer MQW is positioned on a portion of one surface of an n-type semiconductor NSEM. The active layer MQW may contain materials with a single or multiple quantum well structure. If the active layer MQW contains materials with a multiple quantum well structure, it may be a structure in which multiple well layers and barrier layers are alternately stacked. In this case, the well layers are formed of InGaN and the barrier layers are formed of GaN or AlGaN, but are not limited to these. Alternatively, the active layer MQW may be a structure in which semiconductor materials of a type with a large bandgap energy and semiconductor materials with a small bandgap energy are alternately stacked, and may contain different group 3 to group 5 semiconductor materials depending on the wavelength band of the emitted light.

[0076] In one embodiment of the present invention, a flip-chip type light-emitting element was used as an example, but the invention is not limited to this, and a vertical type light-emitting element may also be used.

[0077] Figure 5 is a schematic plan view showing a light-emitting element transfer system according to one embodiment, and Figure 6 is a schematic side view showing a light-emitting element transfer system according to one embodiment.

[0078] Referring to Figures 5 and 6, one embodiment of the light-emitting element transfer system can align a first substrate TS with a second substrate DS on which light-emitting elements are arranged, and bond the light-emitting elements to the second substrate DS.

[0079] In this specification, the first substrate TS is a substrate onto which light-emitting elements are transferred, serving as the object to be processed in a light-emitting element transfer system. The first substrate TS will be described below primarily in the case of a substrate for an inorganic light-emitting display device, as shown in Figure 4.

[0080] The second substrate DS is a substrate on which light-emitting elements are arranged, serving as the object to be processed in the light-emitting element transfer system, and is the substrate that provides light-emitting elements to the first substrate TS.

[0081] Specifically, the light-emitting element transfer system includes a vacuum chamber VC, a loading unit 200, an alignment unit 300, a bonding unit 400, and a first transport unit 500, and may further include a second transport unit 600, a separation unit 700, and a cassette CS. The light-emitting element transfer system may also further include a controller for controlling each component. The controller is connected to each component, for example, the loading unit 200, the alignment unit 300, the bonding unit 400, the first transport unit 500, and the second transport unit 600, and can control the operation of each component.

[0082] A vacuum chamber VC provides an internal process space where manufacturing processes such as alignment, lamination, bonding, laser irradiation, and movement are carried out. The vacuum chamber VC provides a process space that is vacuum, heated, soundproof, cooled, vibration-free, and waterproof, and for this purpose may further include vacuum equipment, air intake equipment, purification equipment, heating equipment, cooling equipment, etc.

[0083] For example, a vacuum chamber VC can maintain a vacuum with a vacuum device including a vacuum pump and a vacuum valve. For example, a vacuum chamber VC may include a gate valve and a door VCD. The gate valve and door may be located on one side of the vacuum chamber VC. A gate valve may be located on one side of the vacuum chamber VC. A first substrate TS and a second substrate DS may be supplied into the vacuum chamber VC via the gate valve. That is, the gate valve can provide a path for the first substrate TS and the second substrate DS to enter and exit. The size of the second substrate DS may be smaller than that of the first substrate TS. For example, the sum of the areas of four second substrates DS may be the same as the area of ​​one first substrate TS.

[0084] The loading section 200, alignment section 300, bonding section 400, and first transport section 500 are arranged inside the vacuum chamber VC. Parts of the loading section 200, alignment section 300, and bonding section 400 may be located outside the vacuum chamber VC, but the loading, alignment, and bonding processes are performed in the same vacuum atmosphere within a single vacuum chamber VC. Therefore, problems such as air being trapped between the first substrate TS and the second substrate DS during the alignment and bonding processes, which would reduce alignment accuracy or hinder the transmission of applied pressure, do not occur.

[0085] The loading section 200 is located on one side of the internal process space of the vacuum chamber VC. For example, the loading section 200 may be located adjacent to the door VCD of the vacuum chamber VC, and the alignment section 300 and bonding section 400 may be located next to the loading section 200. Trays TR1, TR2 or the first substrate TS are loaded into the loading section 200. For example, trays TR1 and TR2, brought in from outside the vacuum chamber VC through the door VCD, are placed on the loading section 200.

[0086] The loading section 200 may include a stage 210, a lifting member 220, and a protruding member 230.

[0087] Stage 210 can be transported and placed on trays TR1, TR2 or the first substrate TS from the outside, but one embodiment illustrates the case where trays TR1 and TR2 are placed. Trays TR1 and TR2 may include a first tray TR1 on which the first substrate TS is placed and a second tray TR2 on which the second substrate DS is placed. Stage 210 has a larger surface area than the first substrate TS.

[0088] The lifting member 220 is positioned on the side or underside of the stage 210 and can raise or lower the stage 210. The lifting member 220 may include a lifting cylinder or the like.

[0089] The protruding members 230 may protrude above the upper surface of the stage 210. For example, one or more protruding members 230 may be arranged around the stage 210 in a pin shape. When the protruding members 230 protrude above the upper surface of the stage 210, the trays TR1 and TR2 placed on the upper surface of the stage 210 are separated from the upper surface of the stage 210, and at least a portion of the back surface of the trays TR1 and TR2 becomes floating (suspended in the air). In this floating state, the trays TR1 and TR2 are easily lifted later by the first transport unit 500.

[0090] If the protruding member 230 does not move up or down, the stage 210 can come into contact with the upper surfaces of the trays TR1 and TR2 by lifting the stage 210 above or above the protruding member.

[0091] In other modifications, the protruding member 230 can be formed to retract or protrude within a groove located on the upper surface of the stage 210.

[0092] The first transport unit 500 is provided to move along a predetermined path via rails or the like arranged inside the vacuum chamber VC, and transports trays TR1 and TR2 from the loading unit 200 to the alignment unit 300, and from the alignment unit 300 to the bonding unit 400. For example, the first transport unit 500 may be, but is not limited to, a vacuum robot. A vacuum robot is a transport robot used in a vacuum environment and includes articulated arms and fingers, so it can stably transport substrates and trays.

[0093] On the other hand, in the bonded state of the first substrate TS and the second substrate DS, even a small impact can cause misalignment between the two substrates. Therefore, transporting the bonded first substrate TS and the second substrate DS to the bonding apparatus in a tray reduces the possibility of misalignment between the two substrates, making it more advantageous.

[0094] The alignment unit 300 is located inside the vacuum chamber VC, adjacent to the loading unit 200.

[0095] The first transport unit 500 can transport the tray TR1 with the first substrate TS in place when the first substrate TS is placed on the tray TR1.

[0096] Furthermore, the first transport unit 500 can transport the aligned and bonded first substrate TS and second substrate DS from the alignment unit 300 to the bonding unit 400. The first transport unit 500 can also transport the first substrate TS and second substrate DS, after the bonding of the light-emitting elements is completed in the bonding unit 400, back to the loading unit 200.

[0097] The alignment unit 300 can align and bond the first substrate TS and the second substrate DS, which are placed on the loading unit 200. For this purpose, the first substrate TS and the second substrate DS may include alignment marks. The alignment unit 300 may also include an alignment stage 310, a first lifting member 320, a first drive member 330, a protruding member 340, a holding member 350, a second lifting member 360, a second drive member 370, and a vision member 380.

[0098] The alignment stage 310, the protruding member 340, the first lifting member 320, and the first drive member 330 are collectively referred to as the stage module.

[0099] The stage module is an alignment stage, and may be a high-precision stage also called a UVW stage. The stage module has high precision for positional alignment. The stage module has a two-layer structure including a first lifting member 320 and a first driving member 330 for driving. The UVW stage allows for high-precision positioning by controlling the rotation direction at both ends of the stage. However, the UVW stage cannot withstand the high pressures compared to a general stage. Therefore, bonding processes that involve high pressure are not performed on the UVW stage, and the bonding process is performed on a separate stage 410.

[0100] The alignment stage 310 can support the first substrate TS or the tray TR1 on which the first substrate TS is placed, and can support the tray TR1 on which the first substrate TS is placed during the alignment process. The alignment stage 310 can have a larger area than the stage 210 of the loading section 200. For example, the alignment stage 310 may be sized such that four first substrate TS are arranged so that they do not overlap at the same time, but is not limited to this.

[0101] Multiple holding mechanisms, such as electrostatic chucks, may be positioned on the upper surface of the alignment stage 310 to hold the tray TR1 in place so that it does not move during the alignment process.

[0102] The alignment stage 310 can be called the alignment stage 310 in order to clearly distinguish it from the stage 210 of the loading section 200.

[0103] The first lifting member 320 is positioned below the alignment stage 310 and raises and lowers the alignment stage 310. The first lifting member 320 may include a lifting cylinder or the like.

[0104] The first drive member 330 is positioned between the first lifting member 320 and the alignment stage 310, and can precisely move or rotate the alignment stage 310 up, down, left, and right on a single plane during the alignment process.

[0105] The protruding member 340 can protrude and retract from the upper surface of the alignment stage 310. For example, the protruding member 340 is positioned in a groove formed on the upper surface of the alignment stage 310 and can protrude above the upper surface of the alignment stage 310 as needed. When the protruding member 340 protrudes, the tray TR1 or first substrate TS positioned above the protruding member 340 can be raised and lowered vertically (in the third direction). For example, one or more protruding members 340 can be arranged around the alignment stage 310 in a pin shape. When the protruding member 340 protrudes from the upper surface of the alignment stage 310, the tray TR1 positioned on the upper surface of the alignment stage 310 is separated from the upper surface of the alignment stage 310, and at least a portion of the back surface of the tray TR1 becomes floating (suspended in the air). In this floating state, trays TR1 and TR2 are easily lifted later by the first transport unit 500.

[0106] The holding member 350 is positioned on the ceiling of the vacuum chamber VC and is positioned to overlap with the alignment stage 310. During the alignment process, the holding member 350 adsorbs or grips the back surface of the second substrate DS to support the second substrate DS on top of the first substrate TS. The holding member 350 may include a holding mechanism such as a vacuum suction system, a mechanical chuck, or an electrostatic chuck. For example, the holding member 350 may, but is not limited to, an electrostatic chuck.

[0107] The second lifting member 360 is positioned above the holding member 350 and can raise and lower the holding member 350. The second lifting member 360 may include a lifting cylinder or the like.

[0108] The second drive member 370 is positioned above the second lifting member 360 and can move or rotate the holding member 350 up, down, left, and right on a single plane.

[0109] The vision member 380 recognizes alignment marks placed on the first substrate TS and the second substrate DS. For example, the vision member 380 may include at least one camera module. The vision member 380, the second lifting member 360, and the second driving member 370 are shown to be located outside the vacuum chamber VC, but are not limited thereto. For example, the vision member 380 may be located inside the vacuum chamber VC.

[0110] The bonding unit 400 can apply heat and pressure to the first substrate TS and the second substrate DS, which have been transported in a bonded state by the first transport unit 500, and irradiate them with a laser to transfer the light-emitting elements arranged on the second substrate DS to the first substrate TS.

[0111] The bonding section 400 may include a heating stage 410, a lifting member 420, a protruding member 430, a pressurizing member 440, and a laser member 450.

[0112] The heating stage 410 may be equipped with a built-in heater. The heater is configured, for example, to generate Joule heat as an electric heater. The heater conducts heat through the heating stage 410, heating the first substrate TS supported by the heating stage 410. By controlling the amount of heat generated by the heater, the temperature of the first substrate TS and its junction surfaces can be adjusted.

[0113] A holding mechanism, such as an electrostatic chuck, may be positioned on the upper surface of the heating stage 410 to hold the first substrate TS in place so that it does not move during the bonding process.

[0114] The lifting member 420 is positioned on the side or underside of the heating stage 410 and can raise or lower the heating stage 410. The lifting member 420 may include a lifting cylinder or the like.

[0115] The protruding member 430 is positioned in a groove formed on the upper surface of the heating stage 410 and can protrude above the upper surface of the heating stage 410 as needed. When the protruding member 430 protrudes, the tray TR1 positioned above the protruding member 430 can be raised and lowered vertically (in the third direction). For example, one or more protruding members 430 can be arranged around the tray TR1 in a pin shape. When the protruding member 430 protrudes above the upper surface of the stage 410, the tray TR1 positioned on the upper surface of the stage 410 is separated from the upper surface of the stage 410, and at least a portion of the back of the tray TR1 becomes floating (suspended in the air). In this floating state, the tray TR1 is easily lifted later by the first transport unit 500.

[0116] The heating stage 410, the lifting member 420, and the protruding member 430 are collectively called a stage module. To clearly distinguish them from the stage module of the alignment section 300, they can also be called a bonding stage module.

[0117] The bonding stage module can withstand higher pressures than the stage module of the alignment section 300.

[0118] The pressurizing member 440 is positioned on the ceiling of the vacuum chamber VC and is positioned to overlap with the heating stage 410. The pressurizing member 440 can pressurize the first substrate TS and the second substrate DS which are sequentially placed on the tray TR1.

[0119] The pressurizing member 440 is made of a transparent material, at least in part. This allows the light emitted from the laser member 450 to pass through the transparent material of the lower pressurizing member 440.

[0120] For transparent materials, glass or ceramic materials are preferable. Even if the material does not appear transparent to the naked eye, it is sufficient if it is composed of a material that transmits light emitted from a light source.

[0121] The laser member 450 may include a drive system that can move up, down, left, and right on one plane. The laser member 450 is positioned on top of the pressurizing member 440 and can irradiate the first substrate TS and the second substrate DS with laser light.

[0122] The laser component 450 can be configured in various ways, such as a configuration that continuously irradiates a specific area or a configuration that scans.

[0123] Once the bonding process is complete, the vacuum atmosphere in the vacuum chamber VC can be broken. A vacuum is generally defined as a space where the atmospheric pressure is lower than normal atmospheric pressure. Breaking the vacuum atmosphere means changing the state of the space from a vacuum. For example, breaking the vacuum atmosphere could, but is not limited to, returning the vacuum chamber VC to normal atmospheric pressure.

[0124] The second transport unit 600 is located outside the vacuum chamber VC and can load the first tray TR1 or the second tray TR2 loaded on the cassette CS into the vacuum chamber VC, or unload the first tray TR1 or the second tray TR2 inside the vacuum chamber VC. The unloaded first tray TR1 and second tray TR2 may be placed in the separation unit 700. The second transport unit 600 may be equipped with a robotic arm or the like capable of transporting trays TR or substrates TS, DS.

[0125] The separation unit 700 separates and loads the first tray TR1 and the first substrate TS placed on the first tray TR1. It can also separate and load the second tray TR2 and the second substrate DS.

[0126] Figures 7 and 8 are enlarged views of the loading section according to the embodiments shown in Figures 5 and 6. Figures 7 and 8 are side views illustrating the movement of the protruding member 230 of the loading section 200. Figure 7 illustrates the state in which the protruding member 230 is inserted into the groove 210-R of the stage 210, and Figure 8 illustrates the state in which the protruding member 230 is protruding from the stage 210.

[0127] Referring to Figure 7, tray TR1 is loaded onto the stage 210 of the loading unit 200. The first substrate TS is placed on tray TR1.

[0128] The protruding member 230 of the loading section 200 is positioned within the groove 210-R of the stage 210. Therefore, the upper surface of the stage 210 becomes flat.

[0129] Tray TR1 is positioned without any gaps on the top surface of stage 210.

[0130] Referring to Figure 8, the protruding member 230 of the loading section 200 protrudes outward, allowing the tray TR1 to be lifted. The tray TR1 becomes floating, separated from the upper surface of the stage 210. The arm of the first transport section 500 is inserted into the space between the tray TR1 and the stage 210, allowing the tray TR1 to be lifted.

[0131] According to one embodiment, the alignment process and the bonding process are performed in the same vacuum atmosphere of a single vacuum chamber, and the alignment process stage and the bonding process stage are made different from each other, thereby enabling the bonding process to be completed without misalignment of the first substrate and the second substrate.

[0132] Figures 9 and 10 are enlarged views of the loading section according to other embodiments of Figures 7 and 8.

[0133] The embodiments shown in Figures 9 and 10 differ from those in Figures 7 and 8 in that the first substrate TS is transported without a tray. In Figures 9 and 10, explanations that overlap with those in Figures 7 and 8 are omitted, and the explanation focuses on the differences from the embodiments in Figures 7 and 8.

[0134] Referring to Figures 9 and 10, the first substrate TS is placed in the cassette CS without a tray. The first substrate TS is transported by the second transport unit 600 to the loading unit 200 in the vacuum chamber VC and placed there. The first substrate TS is then placed in the alignment unit 300 and the bonding unit 400 without a tray, and the process is carried out.

[0135] The loading unit 200 has a protruding member 230 that protrudes to push the first substrate TS away from the stage 210 and into a floating state. The first substrate TS is separated from the upper surface of the stage 210 and is in a floating state. The arm of the first transport unit 500 is inserted into the space between the first substrate TS and the stage 210 and can lift the first substrate TS. The first transport unit 500 transports the first substrate TS from the loading unit 200 to the alignment unit 300.

[0136] According to one embodiment, the alignment process and bonding process can be performed continuously in a high vacuum environment within a single vacuum chamber VC without opening the vacuum chamber, thereby improving the production efficiency of the transfer apparatus.

[0137] Since alignment and bonding processes can be performed in a high vacuum environment, the penetration of moisture or oxygen into the light-emitting elements of the substrate can be minimized. Therefore, the reliability of the substrate, i.e., the elements of the display device, can be improved.

[0138] Figure 11 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 12 is a side view of the light-emitting element transfer system of Figure 11.

[0139] The embodiments shown in Figures 11 and 12 differ from those in Figures 5 and 6 in that the loading section 200 includes a first loading section 200-1 and a second loading section 200-2. In Figures 11 and 12, explanations that overlap with those in Figures 5 and 6 will be omitted, and the explanation will focus on the differences from the embodiment in Figure 5.

[0140] Referring to Figures 11 and 12, the first loading section 200-1 and the second loading section 200-2 are positioned adjacent to the door VCD of the vacuum chamber VC, and the width of the door VCD may be greater than or equal to the width of the first loading section 200-1 and the second loading section 200-2.

[0141] The first loading unit 200-1 loads the first tray TR1, and the second loading unit 200-2 loads the second tray TR2. For example, the second transport unit 600 can transport the first tray TR1 from the cassette CS to the first loading unit 200-1. Also, the second transport unit 600 can transport the second tray TR2 from the cassette CS to the second loading unit 200-2.

[0142] The alignment section 300 and the bonding section 400 may be arranged side by side next to the loading section 200. Trays TR1, TR2 or the first substrate TS are loaded into the loading section 200. For example, trays TR1 and TR2, brought in from outside the vacuum chamber VC through the door VCD, are placed on the loading section 200.

[0143] The first transport unit 500 transports the first tray TR1 on which the first substrate TS is placed from the first loading unit 200-1 to the alignment unit 300, and transports the second tray TR2 on which the second substrate DS is placed from the second loading unit 200-2 to the alignment unit 300. For example, the first transport unit 500 places the first tray TR1 from the first loading unit 200-1 on the upper part of the alignment stage 310 of the alignment unit 300, and the first lifting member 320 rises until the first tray TR1 is placed on the alignment stage 310.

[0144] In another embodiment, the first substrate TS can be loaded onto the cassette CS without a tray. In this case, the second transport unit 600 can load the first substrate TS into the first loading unit 200-1. The travel width of the second transport unit 600 may also be the same as the width of the door VCD. Compared with the embodiment in Figure 5, it can be seen that the transport width of the second transport unit 600 in Figure 11 has been further increased.

[0145] Figure 13 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 14 is a side view of the light-emitting element transfer system of Figure 13.

[0146] Figures 13 and 14 differ from the embodiments in Figures 5 and 6 in that the stage 311 and first drive member 331 of the alignment section 300 have a smaller area than the lifting member 321, the first drive member 331 can move up, down, left, and right on the plane of the lifting member 321, and the lifting member 321 can move left and right as well as vertically. In Figures 13 and 14, explanations that overlap with the embodiments in Figures 5 and 6 will be omitted, and the differences from the embodiments in Figures 5 and 6 will be explained in detail.

[0147] The stage 311, the first lifting member 321, and the first drive member 331 are collectively referred to as the stage module.

[0148] The stage module can be a high-precision stage, also known as an alignment stage or UVW stage.

[0149] Stage 311 is preferably sized to accommodate one first substrate TS.

[0150] Multiple holding mechanisms, such as electrostatic chucks, may be positioned on the upper surface of the stage 311 to hold the tray TR1 in place so that it does not move during the alignment process.

[0151] The first lifting member 321 is positioned below the stage 311 and moves the stage 311 up and down. Moreover, the first lifting member 321 can move the stage 311 and the first drive member 331 up, down, left, and right on a single plane. Therefore, the first lifting member 321 can move the stage 311 not only vertically but also up, down, left, and right on a single plane without the assistance of the first transport unit 500 within the upper surface of the first lifting member 321. For example, the first lifting member 321 can move the stage 311 in a first direction (X direction) and a second direction (Y direction) to move the first tray TR1 to an alignment position with the next second substrate DS.

[0152] The first lifting member 321 may include a lifting cylinder or the like.

[0153] In another embodiment, the first substrate TS is placed in the cassette CS without a tray. The first substrate TS is transported by the second transport unit 600 to the loading unit 200 in the vacuum chamber VC and placed thereon. The first substrate TS is then placed in the alignment unit 300 and the bonding unit 400 without a tray for the process to be carried out.

[0154] The loading unit 200 has a protruding member 230 that protrudes to push the first substrate TS away from the stage 210 and into a floating state. The first substrate TS is separated from the upper surface of the stage 210 and is in a floating state. The arm of the first transport unit 500 is inserted into the space between the first substrate TS and the stage 210 and can lift the first substrate TS. The first transport unit 500 transports the first substrate TS from the loading unit 200 to the alignment unit 300.

[0155] Figure 15 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 16 is a side view of the light-emitting element transfer system of Figure 15.

[0156] Figures 15 and 16 differ from the embodiments in Figures 13 and 14 in that the loading section 200 includes a first loading section 200-1 and a second loading section 200-2. In Figures 15 and 16, explanations that overlap with the embodiments in Figures 13 and 14 will be omitted, and the explanation will focus on the differences from the embodiments in Figures 13 and 14.

[0157] Referring to Figures 15 and 16, the first loading section 200-1 and the second loading section 200-2 are positioned adjacent to the door VCD of the vacuum chamber VC, and the width of the door VCD may be greater than or equal to the width of the first loading section 200-1 and the second loading section 200-2.

[0158] The first loading unit 200-1 loads the first tray TR1, and the second loading unit 200-2 loads the second tray TR2. For example, the second transport unit 600 can transport the first tray TR1 from the cassette CS to the first loading unit 200-1. Also, the second transport unit 600 can transport the second tray TR2 from the cassette CS to the second loading unit 200-2.

[0159] The alignment section 300 and the bonding section 400 may be arranged side by side next to the loading section 200. Trays TR1, TR2 or the first substrate TS are loaded into the loading section 200. For example, trays TR1 and TR2, brought in from outside the vacuum chamber VC through the door VCD, are placed on the loading section 200.

[0160] The first transport unit 500 transports the first tray TR1 on which the first substrate TS is placed from the first loading unit 200-1 to the alignment unit 300, and transports the second tray TR2 on which the second substrate DS is placed from the second loading unit 200-2 to the alignment unit 300. For example, the first transport unit 500 places the first tray TR1 from the first loading unit 200-1 on the upper part of the stage 311 of the alignment unit 300, and the first lifting member 321 rises until the first tray TR1 is placed on the stage 311.

[0161] In another embodiment, the first substrate TS can be loaded onto the cassette CS without a tray. In this case, the second transport unit 600 can load the first substrate TS into the first loading unit 200-1. The travel width of the second transport unit 600 may also be the same as the width of the door VCD. Compared with the embodiment in Figure 13, it can be seen that the transport width of the second transport unit 600 in Figure 15 has been further increased.

[0162] Figure 17 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 18 is a side view of the light-emitting element transfer system of Figure 17. Figure 19 is a perspective view illustrating the configuration of the first transport unit.

[0163] The embodiments in Figures 17 and 18 differ from those in Figures 5 and 6 in that the light-emitting element transfer system does not include a loading unit 200 and the first transport unit 501 is a dual-arm system. In Figures 17 and 18, explanations that overlap with those in Figures 5 and 6 will be omitted, and the explanation will focus on the differences from the embodiment in Figure 5.

[0164] Referring to Figures 17 and 18, the light-emitting element transfer system includes a vacuum chamber VC, an alignment unit 300, a bonding unit 400, and a first transport unit 501, and may further include a second transport unit 600, a separation unit 700, and a cassette CS. The light-emitting element transfer system may also further include a controller that controls each component. The controller is connected to each component, for example, the alignment unit 300, the bonding unit 400, the first transport unit 501, and the second transport unit 600, and can control the operation of each component.

[0165] The second transport unit 600 transports either the first tray TR1 or the second tray TR2 from the cassette CS to the alignment unit 300.

[0166] Since there is no separate loading unit 200, the first transport unit 501 can transport or hold the first tray TR1 and the second tray TR2 using dual arms and wait. For example, multiple second substrates DS are arranged in the second tray TR2, and the first arm can support the second tray TR2 while one of the multiple second substrates DS stored in the second tray TR2 is aligned and attached to the first substrate.

[0167] The vacuum chamber VC may include a door VCD. The width of the door VCD corresponds to the width of trays TR1 and TR2, allowing them to enter and exit. Here, "correspond" means similar to the width of trays TR1 and TR2, but may include additional margins.

[0168] Referring to Figure 19, the first transport unit 501 may be a vacuum robot having dual arms.

[0169] The first transport unit 501 comprises a drive section 510 and one or more arms 520, 530. The arms 520, 530 are attached to the drive section 510, which has a 3-axis or 4-axis drive system, for example, as described later. The arms 520, 530 are shown in the drawings, for example, as 3-link arms, and can be coupled coaxially to the drive section 510 and stacked vertically on top of each other, so as to allow independent theta motion (e.g., using a 4-axis drive) or coupled theta motion (e.g., using a 3-axis drive), where the coupled theta motion causes the robot arm to rotate as a unit around the shoulder axis SX with virtually no extension or contraction. Each arm is driven by a pair of motors and can have any suitable drive pulley configuration. For example, the ratio between the shoulder pulley, elbow pulley, and wrist pulley for each arm may be 1:1:2 or 2:1:2 for non-restrictive illustrative purposes. For example, to extend each arm using a 1:1:2 ratio, each motor in the motor pair rotates substantially equally in opposite directions. For example, to extend each arm using a 2:1:2 ratio, the shoulder pulley is substantially fixed (e.g., substantially does not rotate), and the motor coupled to the upper arm rotates to extend the arm. Theta motion is controlled by rotating the motors in the same direction at substantially the same speed.

[0170] The upper arms 521, 531 and the front arms (forearm, 522, 532) of each arm 520, 530 may be substantially the same length or different. For example, the upper arms 521, 531 may be longer than the front arms 522, 532, or vice versa. For arm sections of substantially the same length, the distance L1 between each of the elbow axes EXA, EXB and the shoulder axis SX may be substantially the same as the distance L2 between each of the elbow axes EXA, EXB and one of the individual wrist axes WXA, WXB.

[0171] The ends of the front arms (522, 532) are equipped with end effectors 523, 533. The end effectors 523, 533 can be configured in any suitable manner to hold one or more substrates TS, DS or trays TR1, TR2. For example, while it has been shown that the end effectors 523, 533 have a single blade to hold a single substrate, it should be understood that the end effectors can have multiple blades to hold multiple substrates.

[0172] The drive section 510 can receive commands from, for example, a controller and, in response, manage the radial motion, circumferential motion, vertical motion, compound motion, and other motions of the arms 520, 530.

[0173] In another embodiment, the first substrate TS is placed in the cassette CS without a tray. The first substrate TS is transported by the second transport unit 600 to the loading unit 200 in the vacuum chamber VC and placed thereon. The first substrate TS is then placed in the alignment unit 300 and the bonding unit 400 without a tray for the process to be carried out.

[0174] The loading unit 200 has a protruding member 230 that protrudes to push the first substrate TS away from the stage 210 and into a floating state. The first substrate TS is separated from the upper surface of the stage 210 and is in a floating state. The arm of the first transport unit 500 is inserted into the space between the first substrate TS and the stage 210 and can lift the first substrate TS. The first transport unit 500 transports the first substrate TS from the loading unit 200 to the alignment unit 300.

[0175] Figure 20 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 21 is a side view of the light-emitting element transfer system of Figure 20.

[0176] The embodiments in Figures 20 and 21 differ from those in Figures 17 and 18 in that the width of the door VCD corresponds to the width of the alignment section 310. In Figures 20 and 21, explanations that overlap with those in Figures 17 and 18 are omitted, and the explanation focuses on the differences from the embodiments in Figures 17 and 18.

[0177] The width of the door VCD corresponds to the width of the alignment unit 310. The travel width of the second transport unit 600 may also be the same as the width of the door VCD. Therefore, the second transport unit 600 can load the first tray TR1 and the second tray TR2 into the alignment unit 310 and load the first tray TR1 and the second tray TR2 into different positions on the alignment unit 310. For example, the second transport unit 600 may first place the second tray TR1 in the first area and then place the first tray TR1 in the second area. The first and second areas are adjacent to each other but do not overlap. The second area may be closer to the second transport unit 600 than the first area.

[0178] In other embodiments, the first substrate TS is placed in the cassette CS without a tray. The second transport unit 600 may first place the second tray TR1 in the first region and then place the first substrate TS in the second region. The first and second regions are adjacent to each other but do not overlap. The second region may be closer to the second transport unit 600 than the first region.

[0179] Figure 22 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 23 is a side view of the light-emitting element transfer system of Figure 22.

[0180] The embodiments shown in Figures 22 and 23 differ from those in Figures 17 and 18 in that the stage 311 and the first drive member 331 of the alignment unit 300 have a smaller area than the lifting member 321, the first drive member 331 can move up, down, left, and right on the plane of the lifting member 321, and the lifting member 321 can move left and right as well as vertically. In Figures 22 and 23, explanations that overlap with the embodiments in Figures 17 and 18 will be omitted, and the explanation will focus on the differences from the embodiments in Figures 17 and 18.

[0181] The stage 311, the first lifting member 321, and the first drive member 331 are collectively referred to as the stage module.

[0182] The stage module can be a high-precision stage, also known as an alignment stage or UVW stage.

[0183] Stage 311 is preferably sized to accommodate one first substrate TS.

[0184] Multiple holding mechanisms, such as electrostatic chucks, may be positioned on the upper surface of the stage 311 to hold the tray TR1 in place during the alignment process.

[0185] The first lifting member 321 is positioned below the stage 311 and can raise and lower the stage 311. Moreover, the first lifting member 321 can move the stage 311 and the first drive member 331 up, down, left, and right on a single plane. Therefore, the first lifting member 321 can move the stage 311 not only vertically but also up, down, left, and right on a single plane without the assistance of the first transport unit 500 within the upper surface of the first lifting member 321. For example, the first lifting member 321 can move the stage 311 in a first direction (X direction) and a second direction (Y direction) to move the first tray TR1 to a position aligned with the next second substrate DS.

[0186] The first lifting member 321 may include a lifting cylinder or the like.

[0187] In other embodiments, the first substrate TS is placed in the cassette CS without a tray. The second transport unit 600 may first place the second tray TR1 in the first region and then place the first substrate TS in the second region. The first and second regions are adjacent to each other but do not overlap. The second region may be closer to the second transport unit 600 than the first region.

[0188] Figure 24 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 25 is a side view of the light-emitting element transfer system of Figure 24.

[0189] Figures 24 and 25 differ most significantly in that the first transport unit 501 is not located within the vacuum chamber VC. They also differ from the embodiments in Figures 17 and 18 in that the stage 312 in the alignment region AE is equipped with a heater and also serves as the stage in the bonding region, and the width of the door VCD corresponds to the width of the alignment unit 310. In Figures 24 and 25, explanations that overlap with the embodiments in Figures 17 and 18 are omitted, and the explanation focuses on the differences from the embodiments in Figures 17 and 18.

[0190] Referring to Figures 24 and 25, the light-emitting element transfer system includes a vacuum chamber VC, a stage module STG, an alignment unit 302, and a bonding unit 402, and may further include a transport unit 600, a separation unit 700, and a cassette CS. The light-emitting element transfer system may also further include a controller for controlling each component. The controller is connected to each component, for example, the stage module STG, the alignment unit 300, the bonding unit 400, and the second transport unit 600, and can control the operation of each component.

[0191] The stage module STG may include a stage 312, a stage drive member 322, and a protruding member 342.

[0192] Stage 312 is equipped with a built-in heater 312-h. The heater is configured to generate Joule heat, for example, as an electric heater. The heater conducts heat through Stage 312, heating the first substrate TS supported by Stage 312. By controlling the amount of heat generated by the heater, the temperature of the first substrate TS and its junction can be adjusted.

[0193] Stage 312 can have an area large enough to accommodate the first tray TR1 and the second tray TR2 side by side. On the other hand, the stage drive member 322 can be positioned wider than stage 312 so as to be able to overlap the alignment region AE and the bonding region BDE. Stage 312 is movable on stage drive member 322.

[0194] Multiple holding mechanisms, such as electrostatic chucks, may be positioned on the upper surface of the stage 312 to hold the first tray TR1 in place during the alignment process.

[0195] The protruding member 342 is positioned in a groove formed on the upper surface of the stage 312 and can protrude above the upper surface of the stage 312 as needed. When the protruding member 342 protrudes, the first substrate TS positioned above the protruding member 342 can be raised and lowered vertically (in the third direction). For example, one or more protruding members 342 can be arranged around the stage 312 in a pin shape. When the protruding member 342 protrudes above the upper surface of the stage 312, the first substrate TS positioned on the upper surface of the stage 312 is separated from the upper surface of the stage 312, and at least a portion of the back of the tray TR1 becomes floating (suspended in the air).

[0196] The stage drive member 322 is positioned below the stage 312 and can precisely move the stage 312 up, down, left, and right on a single plane, or rotate it. The stage drive member 322 cannot move vertically.

[0197] The stage drive member 322 can be positioned widely within the vacuum chamber VC, not only in the alignment region AE but also in the bonding region BDE. Therefore, the stage 312 can move not only in the alignment region AE but also in the bonding region BDE.

[0198] The alignment section 302 may include a holding member 350, a second lifting member 360, a second drive member 370, and a vision member 380.

[0199] The bonding portion 402 may include a pressurizing member 440-1 and a laser member 450.

[0200] The pressurizing member 440-1 may include a pressurizing plate 441, a support portion 442, a window 444, and a pressurizing drive portion 445.

[0201] The pressure plate 441 is made of a transparent material, at least in part. This allows light emitted from the laser member 450 to pass through the transparent material of the lower pressure member 440-1. It is preferable to use quartz, glass, or ceramic as the transparent material. Even if it does not appear transparent to the naked eye, it is sufficient if the material allows light emitted from the light source to pass through.

[0202] The support portion 442 connects the pressure plate 441 and the pressure drive unit 445, and supports the pressure plate 441. The support portion 442 is attached to a part of the outer surface of the pressure plate 441, but is not limited to this.

[0203] The pressurizing drive unit 445 is positioned so as not to overlap with the direction of laser beam propagation and is located outside the vacuum chamber VC.

[0204] The pressurizing drive unit 445 allows the pressurizing plate 441 to move downward, thereby pressurizing components located below the pressurizing plate 441. For example, if the pressurizing plate 441 is positioned to overlap with the stage 312, the first substrate TS to which the second substrate DS, located on the stage 312, is bonded can be pressurized. During pressurization, the laser member 450 can emit a laser beam toward the first substrate TS.

[0205] Window 444 is located on the upper surface (ceiling) of the vacuum chamber VC. The window 444 of the chamber may be positioned to overlap with the bonding region BDE of the vacuum chamber VC.

[0206] The window 444 is made of a transparent material that can transmit the laser beam emitted from the laser member 450. The laser beam emitted from the laser member 450, which is located outside the vacuum chamber VC, can enter the vacuum chamber VC through the window 444.

[0207] The window 444 is positioned between the laser member 450 and the pressure plate 441. That is, the window 444 may be positioned so as to overlap the laser member 450 and the pressure plate 441.

[0208] Window 444 is made of a transparent material, at least in part. Preferably, quartz, glass, or ceramic materials are used as the transparent material. It is sufficient if the material does not appear transparent to the naked eye, as long as it transmits light emitted from a light source.

[0209] Window 444 may have a rectangular planar shape. It may also have a circular planar shape, but is not limited to this.

[0210] Figure 26 is a schematic plan view showing a light-emitting element transfer system according to another embodiment, and Figure 27 is a side view of the light-emitting element transfer system of Figure 26.

[0211] Figures 26 and 27 differ most significantly in that the first transport unit 501 is not located within the vacuum chamber VC. They also differ from the embodiments in Figures 17 and 18 in that the stage 312 in the alignment region AE is equipped with a heater and also serves as the stage in the bonding region, and the width of the door VCD corresponds to the width of the alignment unit 310. In Figures 26 and 27, explanations that overlap with the embodiments in Figures 17 and 18 are omitted, and the explanation focuses on the differences from the embodiments in Figures 17 and 18.

[0212] Referring to Figures 26 and 27, the light-emitting element transfer system includes a vacuum chamber VC, a stage module STG, an alignment unit 302, and a bonding unit 402, and may further include a transport unit 600, a separation unit 700, and a cassette CS. The light-emitting element transfer system may also further include a controller for controlling each component. The controller is connected to each component, for example, the stage module STG, the alignment unit 302, the bonding unit 402, and the second transport unit 600, and can control the operation of each component.

[0213] The stage module STG may include a stage 312, a stage drive member 322, a stage lifting member 332, and a protruding member 342.

[0214] Stage 312 is equipped with a built-in heater 312-h. The heater is configured to generate Joule heat, for example, as an electric heater. The heater conducts heat through Stage 312, heating the first substrate TS supported by Stage 312. By controlling the amount of heat generated by the heater, the temperature of the first substrate TS and its junction can be adjusted.

[0215] Multiple holding mechanisms, such as electrostatic chucks, may be positioned on the upper surface of the stage 312 to hold the tray TR1 in place during the alignment process.

[0216] The protruding member 342 is positioned in a groove formed on the upper surface of the stage 312 and can protrude above the upper surface of the stage 312 as needed. When the protruding member 342 protrudes, the first substrate TS positioned above the protruding member 342 can be raised and lowered vertically (in the third direction). For example, one or more protruding members 342 can be arranged around the stage 312 in a pin shape. When the protruding member 342 protrudes above the upper surface of the stage 312, the first substrate TS positioned on the upper surface of the stage 312 is separated from the upper surface of the stage 312, and at least a portion of the back of the tray TR1 becomes floating (suspended in the air).

[0217] The stage drive member 322 is positioned below the stage 312 and can precisely move the stage 312 up, down, left, and right on a single plane, or rotate it. The stage drive member 322 cannot move vertically.

[0218] The stage drive member 322 can be positioned widely within the vacuum chamber VC, not only in the alignment region AE but also in the bonding region BEA. Therefore, the stage 312 can move not only in the alignment region AE but also in the bonding region BEA.

[0219] The stage lifting member 332 is positioned on the side or underside of the stage 312 and can raise or lower the stage 312. The stage lifting member 332 may include a lifting cylinder or the like.

[0220] In other embodiments, the alignment section 302 may not include the second lifting member 360. Therefore, the holding member 350 can move up, down, left, and right and rotate on a single plane by the second drive member 370, but it cannot move vertically.

[0221] Figure 28 is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment.

[0222] The transfer apparatus described with reference to Figure 28 may be the same as the transfer apparatus described with reference to Figures 6 to 23.

[0223] The second transport unit 600 supplies the first substrate TS or trays TR1, TR2 to the vacuum chamber (S110 in Figure 28).

[0224] As shown in Figures 6, 11 to 16, if the transfer apparatus includes a loading unit 200, the second transport unit 600 transports the first substrate TS or trays TR1, TR2 into the vacuum chamber to the stage 210 of the loading unit 200.

[0225] The first substrate TS may be transported together with the first tray TR1 while placed on the first tray TR1. In other embodiments, the first substrate TS may be transported as is, without the first tray TR1.

[0226] On the other hand, as shown in Figures 17 to 23, if the transfer apparatus does not include a loading unit 200, the second transport unit 600 transports the first substrate TS or trays TR1, TR2 to the upper surface of the stage of the alignment unit 300.

[0227] The vacuum chamber VC creates a vacuum inside the vacuum chamber (S120 in Figure 28).

[0228] For example, a vacuum chamber VC can maintain a vacuum state using a vacuum pump and a vacuum valve.

[0229] The first transport unit 500 transports the first tray TR1 and the second tray TR2 to the alignment unit 300 (S130 in Figure 28).

[0230] The first transport unit 500 may be a vacuum robot. The vacuum robot may include a servo motor and a 3-axis or 4-axis arm that can be used in a vacuum. The first transport unit 500 may include one arm or a dual arm.

[0231] As shown in Figures 6, 11 to 16, the first transport unit 500 can transport the first substrate TS or trays TR1, TR2 from the stage 210 of the loading unit 200 to the alignment unit 300 when the first substrate TS or trays TR1, TR2 are loaded onto the stage 210 of the loading unit 200.

[0232] For example, the first tray TR1 (on which the first substrate TS is placed) or the first substrate TS can be placed on the alignment stage 310 (e.g., the UVW stage) of the alignment unit 300.

[0233] Furthermore, the first transport unit 500 brings the back surface of one of the multiple second substrates DS placed on the second tray TR2 into contact with the holding member 350. Multiple light-emitting elements are arranged on one side of the second substrate DS, and the back surface refers to the surface opposite to the aforementioned side.

[0234] Subsequently, the second substrate DS and the first substrate TS are aligned and bonded together (S140 in Figure 28).

[0235] The holding member 350 attracts or grips the second substrate DS upon contact. For example, electricity is applied to the holding member 350, and the electrostatic chuck allows the holding member 350 to attract the back surface of the second substrate DS. In this case, multiple light-emitting elements placed on one surface of the second substrate DS can be arranged to face the alignment stage 310.

[0236] The first lifting member 320 of the alignment section 300 is raised, or the protruding member 340 is lowered, bringing the alignment stage 310 into contact with the first tray TR1 or the first substrate TS. A holding mechanism such as an electrostatic chuck of the alignment stage 310 attracts or grips the first tray TR1 or the first substrate TS (on which the first substrate TS is placed).

[0237] Subsequently, the second lifting member 360 lowers the holding member 350, and the UVW stage aligns the first substrate TS and the second substrate DS. For example, the alignment marks of the first substrate TS and the second substrate DS can be checked with the vision member 380, and the UVW stage moves the first substrate TS to match the positions of the alignment marks of the first substrate TS and the second substrate DS, thereby aligning the first substrate TS and the second substrate DS.

[0238] After aligning the first substrate TS and the second substrate DS, the suction or gripping state of the holding member 350 is released. This separates the second substrate DS from the holding member 350 and fuses the first substrate TS and the second substrate DS together.

[0239] All other second substrates DS on the second tray TR2 are aligned and bonded to the other areas of the first substrate TS.

[0240] Once one second substrate DS is bonded, the first transport unit 500 can adjust the position of the first substrate TS before another new second substrate DS is bonded. For example, if the first substrate TS is a large substrate, the first transport unit 500 can adjust the position of the first substrate TS so that the next alignment area on the first substrate TS overlaps with the holding member 350. When the first transport unit 500 adjusts the position of the first substrate TS, the electrostatic chuck of the alignment stage 310 releases its suction or gripping state, and once the position adjustment of the first substrate TS is complete, the electrostatic chuck of the alignment stage 310 suctions or grips the first substrate TS.

[0241] Subsequently, the alignment stage 310 is lowered below the protruding member 340 by the lifting member 320, or the protruding member 340 is extended so that it protrudes from the top of the alignment stage 310. As a result, the first substrate TS, which is bonded to the second substrate DS, is supported by the protruding member 340 and becomes floating.

[0242] The first transport unit 500 transports the first substrate TS, which has been bonded to the second substrate DS, to the bonding unit 400 (S150 in Figure 28).

[0243] At this time, if the first substrate TS is placed on the first tray TR1, the first transport unit 500 can transport the first tray TR1 with the first substrate TS contained in it to the bonding unit 400 and place it on the stage of the bonding unit 400.

[0244] The drive module of the alignment section 300 (first lifting member 320 and first drive member 330) is suitable for precise alignment adjustment, but has a small load capacity. On the other hand, the drive module of the bonding section 400 (lifting member 420) has a large load capacity, but is difficult to adjust for alignment.

[0245] Therefore, when the alignment unit 300 and the drive unit 400 are used separately, as in one embodiment, there is the advantage of being able to withstand the strong pressure during precise alignment and bonding. In addition, since the alignment unit 300 and the drive unit 400 are located in a single vacuum chamber, the alignment process and bonding process can be performed continuously in a high vacuum environment, thereby improving production efficiency.

[0246] The bonding unit 400 applies heat and pressure to bond the multiple light-emitting elements arranged on the second substrate DS to the first substrate TS (S160 in Figure 28).

[0247] For example, the electrostatic chuck of the bonding section 400 stage 410 raises the lifting member 420 or inserts the protruding member 430 into the groove, bringing the alignment stage 310 and the first tray TR1 or first substrate TS into contact with the upper surface of the stage 410. A holding mechanism such as the electrostatic chuck of the stage 410 adsorbs or grips the first tray TR1 or first substrate TS (on which the first substrate TS is placed).

[0248] The lifting member 420 is raised to bring the second substrate DS, which is bonded to the first substrate TS, into contact with the pressurizing member 440. The pressurizing member 440 applies pressure to the first substrate TS, which is bonded to the second substrate DS.

[0249] The heater built into stage 410 is activated to apply heat to the first board TS, which is bonded to the second board DS.

[0250] If necessary, the laser member 450 irradiates the first substrate TS, which is bonded to the second substrate DS, or the boundary between the second substrate DS and the first substrate TS, above the pressurizing member 440.

[0251] The laser component 450 can be implemented using a variety of laser irradiation methods, such as a method that continuously irradiates a specific area or a method that scans the area.

[0252] In this way, by applying heat and pressure to the first substrate TS which is bonded to the second substrate DS, the light-emitting element of the second substrate DS and the first substrate TS can be bonded together.

[0253] After bonding is complete, the stage 410 is lowered below the protruding member 430 by the lifting member 420, or the protruding member 430 is extended so that it protrudes from the top of the stage 410. As a result, the first substrate TS, which is bonded to the second substrate DS, is supported by the protruding member 430 and floats above the top surface of the stage 410.

[0254] The first transport unit 500 unloads the first substrate TS bonded to the second substrate DS. For example, as shown in Figures 6, 11 to 16, if the transfer apparatus includes a loading unit 200, the first transport unit 500 transports the first substrate TS bonded to the second substrate DS to the stage 210 of the loading unit 200.

[0255] If the transfer apparatus does not include a loading unit 200, the first transport unit 500 transports the first substrate TS bonded to the second substrate DS to the upper surface of the stage of the alignment unit 300.

[0256] The vacuum chamber VC breaks the vacuum atmosphere inside the vacuum chamber (S170 in Figure 28).

[0257] The second transport unit 600 unloads the first substrate TS, which is bonded to the second substrate DS, from the vacuum chamber VC (S180 in Figure 28).

[0258] The first substrate TS is transported together with the first tray TR1 while placed on the first tray TR1. In other embodiments, the first substrate TS can be transported as is without the first tray TR1.

[0259] The second transport unit 600 transports the first substrate TS, which is bonded to the second substrate DS that has been unloaded, to the separation unit 700. The second transport unit 600 can separate the second substrate DS from the first substrate TS that has been unloaded. Since the adhesive force between the second substrate DS and the light-emitting element LE placed on the second substrate DS is much weaker than the adhesive force between the light-emitting element LE and the first substrate TS, the second substrate DS and the light-emitting element LE can be easily separated by an external force. In addition, the first substrate TS can be separated from the first tray TR1.

[0260] Figure 29 is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment.

[0261] The transfer apparatus described with reference to Figure 29 may be the same as the transfer apparatus described with reference to Figures 24 to 27.

[0262] The second transport unit 600 loads the first tray TR1 on which the first substrate TS is placed, or the second tray TR2 on which multiple second substrates DS are placed, onto the stage 312 of the stage module STG of the vacuum chamber VC (S210 in Figure 29).

[0263] As shown in Figures 24 to 27, the second transport unit 600 transports the first substrate TS or trays TR1 and TR2 to the upper surface of the stage 312 of the stage module STG.

[0264] The first substrate TS can be transported together with the first tray TR1 while placed on the first tray TR1. In other embodiments, the first substrate TS can be transported as is without the first tray TR1.

[0265] The vacuum chamber VC creates a vacuum inside the vacuum chamber (S220 in Figure 29).

[0266] For example, a vacuum chamber VC can maintain a vacuum state using a vacuum pump and a vacuum valve.

[0267] The stage module STG transports the substrate TS, DS or trays TR1, TR2 to the alignment area AE (S230 in FIG. 29).

[0268] Move the stage 312 on the stage driving member 322 to place the first tray TR1 or the first substrate TS in the alignment area AE.

[0269] Lower the protruding member 340 of the stage module STG to bring the stage 312 into contact with the first tray TR1 or the first substrate TS.

[0270] A holding mechanism such as an electrostatic chuck of the stage 312 adsorbs or grips the first tray TR1 or the first substrate TS (on which the first substrate TS is placed).

[0271] Thereafter, align and bond the second substrate DS and the first substrate TS (S240 in FIG. 29).

[0272] For example, the second elevating member 360 lowers the holding member 350, and the second driving member 370 moves the holding member 350 to align the first substrate TS and the second substrate DS. For example, the alignment marks of the first substrate TS and the second substrate DS are confirmed by the vision member 380, and the second driving member 370 moves the holding member 350 to align the positions of the alignment marks of the first substrate TS and the second substrate DS, whereby the first substrate TS and the second substrate DS can be aligned.

[0273] After aligning the first substrate TS and the second substrate DS, release the adsorption or gripping state of the holding member 350. Thereby, the second substrate DS is separated from the holding member 350, and the first substrate TS and the second substrate DS are bonded together.

[0274] Align and bond all the other second substrates DS on the second tray TR2 to other areas of the first substrate TS.

[0275] Once one second substrate DS is bonded, the stage module STG can adjust the position of the first substrate TS before any other new second substrates DS are bonded. For example, if the first substrate TS is a large substrate, the stage module STG can adjust the position of the first substrate TS so that the next alignment region on the first substrate TS overlaps with the holding member 350. This allows the second substrates DS to exist bonded to the entire first substrate TS.

[0276] The stage module STG transports the first substrate TS, which is bonded to the second substrate DS, to the bonding region BDE (S250 in Figure 29).

[0277] For example, the stage 312 is moved on the stage drive member 322 to transport the first tray TR1 or the first substrate TS to the bonding region BDE.

[0278] Multiple light-emitting elements arranged on the second substrate DS are bonded to the first substrate TS in the bonding region BDE (S260 in Figure 29).

[0279] As shown in Figures 24 and 25, if the pressurizing member 440-1 includes a pressurizing drive unit 445, the pressurizing member 440-1 is lowered in the bonding region BDE to bring the second substrate DS, which is bonded to the first substrate TS, into contact with the pressurizing member 440-1. The pressurizing member 440-1 then applies pressure to the first substrate TS, which is bonded to the second substrate DS.

[0280] On the other hand, as shown in Figures 26 and 27, if the pressurizing member 440-1 does not include a pressurizing drive unit 445 and the stage module STG includes a stage lifting member 332, the stage lifting member 332 is raised to bring the second substrate DS, which is bonded to the first substrate TS, into contact with the pressurizing member 440-1. The pressurizing member 440 pressurizes the first substrate TS, which is bonded to the second substrate DS.

[0281] Subsequently, the heater built into stage 312 is activated to apply heat to the first substrate TS, which is bonded to the second substrate DS.

[0282] If necessary, the laser member 450 above the pressurizing member 440-1 irradiates the first substrate TS bonded to the second substrate DS or the boundary between the second substrate DS and the first substrate TS with a laser. The laser emitted from the laser member 450 can pass through the window 444 and the pressurizing plate 441 of the pressurizing member 440-1 and irradiate the first substrate TS bonded to the second substrate DS or the boundary between the second substrate DS and the first substrate TS.

[0283] The laser component 450 can be implemented using a variety of laser irradiation methods, such as a method that continuously irradiates a specific area or a method that scans it.

[0284] In this way, by applying heat and pressure to the first substrate TS which is bonded to the second substrate DS, the light-emitting element of the second substrate DS and the first substrate TS can be bonded together.

[0285] The vacuum chamber VC breaks the vacuum atmosphere inside the vacuum chamber (S270 in Figure 29).

[0286] The second transport unit 600 unloads the first substrate TS, which is bonded to the second substrate DS, from the vacuum chamber VC (S280 in Figure 29).

[0287] The first substrate TS can be transported together with the first tray TR1 while placed on the first tray TR1. In other embodiments, the first substrate TS can be transported as is without the first tray TR1.

[0288] The second transport unit 600 transports the first substrate TS, which is bonded to the second substrate DS that has been unloaded, to the separation unit 700. The second transport unit 600 can separate the second substrate DS from the first substrate TS that has been unloaded. Since the adhesive force between the second substrate DS and the light-emitting element LE placed on the second substrate DS is much weaker than the adhesive force between the light-emitting element LE and the first substrate TS, the second substrate DS and the light-emitting element LE can be easily separated by an external force. In addition, the first substrate TS can be separated from the first tray TR1.

[0289] FIG. 30 is an exemplary diagram showing a smartwatch including a display device according to an embodiment.

[0290] Referring to FIG. 30, a display device 10_1 according to an embodiment can be applied to a smartwatch 1000_1 which is one of smart devices.

[0291] FIGS. 31 and 32 are exemplary diagrams showing a virtual reality device including a display device according to an embodiment.

[0292] Referring to FIGS. 31 and 32, a head-mounted display device 1000_2 according to an embodiment includes a first display device 10_2, a second display device 10_3, a display device housing portion 1100, a housing cover 1200, a first eyepiece lens 1210, a second eyepiece lens 1220, a head mounting band 1300, a middle frame 1400, a first optical member 1510, a second optical member 1520, and a control circuit board 1600.

[0293] The first display device 10_2 provides an image to the user's left eye, and the second display device 10_3 provides an image to the user's right eye. Since each of the first display device 10_2 and the second display device 10_3 is substantially the same as the display device 100 described with reference to FIGS. 1 and 2, the descriptions related to the first display device 10_2 and the second display device 10_3 are omitted.

[0294] The first optical member 1510 is disposed between the first display device 10_2 and the first eyepiece lens 1210. The second optical member 1520 is disposed between the second display device 10_3 and the second eyepiece lens 1220. Each of the first optical member 1510 and the second optical member 1520 may include at least one convex lens.

[0295] The middle frame 1400 is disposed between the first display device 10_2 and the control circuit board 1600, and is disposed between the second display device 10_3 and the control circuit board 1600. The middle frame 1400 serves to support and fix the first display device 10_2, the second display device 10_3, and the control circuit board 1600.

[0296] The control circuit board 1600 is positioned between the middle frame 1400 and the display device housing 1100. The control circuit board 1600 can be connected to the first display device 10_2 and the second display device 10_3 via connectors. The control circuit board 1600 can convert an externally input video source into digital video data DATA and transmit the digital video data DATA to the first display device 10_2 and the second display device 10_3 via connectors.

[0297] The control circuit board 1600 can transmit digital video data corresponding to the left eye image optimized for the user's left eye to the first display device 10_2, and digital video data corresponding to the right eye image optimized for the user's right eye to the second display device 10_3. Alternatively, the control circuit board 1600 can transmit the same digital video data to both the first display device 10_2 and the second display device 10_3.

[0298] The display device housing 1100 houses the first display device 10_2, the second display device 10_3, the middle frame 1400, the first optical member 1510, the second optical member 1520, and the control circuit board 1600. The housing cover 1200 is positioned to cover one open side of the display device housing 1100. The housing cover 1200 may include a first eyepiece 1210 in which the user's left eye is positioned and a second eyepiece 1220 in which the user's right eye is positioned. Figures 31 and 32 show the first eyepiece 1210 and the second eyepiece 1220 being positioned separately, but the embodiments herein are not limited thereto. The first eyepiece 1210 and the second eyepiece 1220 can be integrated.

[0299] The first eyepiece 1210 is aligned with the first display device 10_2 and the first optical element 1510, and the second eyepiece 1220 is aligned with the second display device 10_3 and the second optical element 1520. Therefore, the user can view the image of the first display device 10_2, which has been magnified as a virtual image by the first optical element 1510, through the first eyepiece 1210, and can view the image of the second display device 10_3, which has been magnified as a virtual image by the second optical element 1520, through the second eyepiece 1220.

[0300] The head mounting band 1300 secures the display device housing 1100 to the user's head so that the first eyepiece 1210 and the second eyepiece 1220 of the storage cover 1200 remain positioned for the user's left and right eyes, respectively. If the display device housing 1100 is lightweight and compact, the head-mounted display device 1000_2 can be equipped with a spectacle frame instead of the head mounting band 1300, as shown in Figure 33.

[0301] In addition, the head-mounted display device 1000_2 may further include a battery for supplying power, an external memory slot for storing external memory, and an external connection port and wireless communication module for receiving video sources. The external connection port may be a USB (universe serial bus) terminal, a DisplayPort, or an HDMI® (high-definition multimedia interface) terminal, and the wireless communication module may be a 5G communication module, a 4G communication module, a Wi-Fi module, or a Bluetooth® module.

[0302] Figure 33 is an illustrative diagram showing a virtual reality device including a display device according to another embodiment. Figure 33 shows a virtual reality device 1000_3 to which a display device 10_4 according to one embodiment is applied.

[0303] Referring to Figure 33, one embodiment of the virtual reality device 1000_3 may be a glasses-type device. One embodiment of the virtual reality device 1000_3 comprises a display device 10_4, a left eye lens 10a, a right eye lens 10b, a support frame 20, temples 30a, 30b, a reflective member 40, and a display device housing 50.

[0304] Figure 33 shows that the virtual reality device 1000_3 is a glasses-type display device including temples 30a and 30b. In other words, the virtual reality device 1000_3 according to one embodiment is not limited to the one shown in Figure 33, but can be applied in various forms to various other electronic devices.

[0305] The display device housing 50 may include a display device 10_4 and a reflective member 40. The image displayed on the display device 10_4 is reflected by the reflective member 40 and provided to the user's right eye via the right eye lens 10b. This allows the user to view the virtual reality image displayed on the display device 10_4 through their right eye.

[0306] Figure 33 shows that the display device housing 50 is located at the right end of the support frame 20, but the embodiments herein are not limited to this. For example, the display device housing 50 can be located at the left end of the support frame 20, in which case the image displayed on the display device 10_4 is reflected by the reflective member 40 and provided to the user's left eye via the left eye lens 10a. This allows the user to view the virtual reality image displayed on the display device 10_4 through their left eye. Alternatively, the display device housing 50 can be located at both the left and right ends of the support frame 20, in which case the user can view the virtual reality image displayed on the display device 10_4 through both their left and right eyes.

[0307] Figure 34 is an illustrative diagram showing the instrument panel and center fascia of a vehicle including a display device according to one embodiment. Figure 34 shows a vehicle to which display devices 10_a, 10_b, 10_c, 10_d, and 10_e according to one embodiment are applied.

[0308] Referring to Figure 34, the display devices 10_a, 10_b, and 10_c according to one embodiment can be applied to the vehicle's instrument panel, the vehicle's center fascia, or a CID (Center Information Display) located on the vehicle's dashboard. In addition, the display devices 10_d and 10_e according to one embodiment can be applied to a rearview mirror display that replaces the vehicle's side mirrors.

[0309] Figure 35 is an illustrative diagram showing a transparent display device including a display device according to one embodiment.

[0310] Referring to Figure 35, a display device 10_5 according to one embodiment can be applied to a transparent display device. A transparent display device can display video IM while simultaneously transmitting light. Therefore, a user positioned in front of the transparent display device can not only view the video IM displayed on the display device 10_5, but also see objects RS or the background located behind the transparent display device. When the display device 10_5 is applied to a transparent display device, the substrate of the display device 10_5 can include a light-transmitting portion that can transmit light, or can be formed from a light-transmitting material.

[0311] Although embodiments of the present invention have been described above with reference to the attached drawings, the present invention is not limited to the embodiments described above and can be manufactured in a variety of different forms. A person with ordinary skill in the art to which the present invention belongs will understand that the invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above embodiments should be understood to be illustrative and not limiting in all respects. [Explanation of Symbols]

[0312] 100 display device VC Vacuum Chamber TS 1st board DS 2nd board 200 Loading section 300 Alignment Section 400 Bonding section 500 First Conveyor Unit 600 Second Conveyor Unit CS Cassette

Claims

1. A vacuum chamber that creates or breaks a vacuum atmosphere inside, An alignment unit for aligning the first substrate and the second substrate inside the vacuum chamber, A bonding section is located inside the vacuum chamber adjacent to the alignment section and applies heat and pressure to the aligned first and second substrates. A light-emitting element transfer system, comprising a first transport unit arranged to be movable in a first or second direction within the vacuum chamber, which transports a first substrate or a second substrate to an alignment unit, and transports the first substrate and the second substrate aligned in the alignment unit to the bonding unit.

2. The alignment section is, A stage module having a holding mechanism on its upper surface to prevent movement of the substrate or tray, and a protruding member that can be extended and retracted, which supports the first substrate during the alignment process, A holding member positioned on top of the stage module, which suctions or grips the back surface of the second substrate in order to support the second substrate on top of the first substrate, A second drive member that moves the holding member on a single plane, The light-emitting element transfer system according to claim 1, further comprising a vision member for capturing the alignment of the first substrate and the second substrate.

3. The aforementioned stage module is a UVW stage, The light-emitting element transfer system according to claim 2, wherein the first transport unit is a vacuum robot.

4. The light-emitting element transfer system according to claim 3, wherein the vacuum robot includes a dual arm.

5. The bonding portion is, A stage including a holding mechanism, a protruding member and a heater, A lifting member for raising and lowering the aforementioned stage in the vertical direction, A pressing member is placed on the stage and pressurizes the substrate placed on the stage, and transmits laser light, The light-emitting element transfer system according to claim 1, further comprising a laser member that emits laser light onto a substrate placed on the stage at the upper part of the pressurizing member.

6. The light-emitting element transfer system according to claim 1, further comprising a loading section disposed inside the vacuum chamber on which a substrate or tray is loaded.

7. The light-emitting element transfer system according to claim 6, wherein the loading section further includes a first loading section into which a first substrate or a first tray containing the first substrate is loaded, and a second loading section into which a second tray containing a second substrate is loaded.

8. The vacuum chamber includes a chamber door located on one side. The light-emitting element transfer system according to claim 1, wherein a tray on which a first substrate or a second substrate is placed enters and exits the vacuum chamber via the chamber door.

9. A cassette is placed outside the vacuum chamber and holds trays on which the first or second substrate is placed. The light-emitting element transfer system according to claim 1, further comprising a second transport unit disposed outside the vacuum chamber for transporting trays loaded on the cassette into the vacuum chamber.

10. A vacuum chamber that creates or breaks a vacuum atmosphere inside, An alignment unit for aligning the first substrate and the second substrate inside the vacuum chamber, A bonding section is located inside the vacuum chamber adjacent to the alignment section and applies heat and pressure to the aligned first and second substrates. A stage including a heater is movably disposed between the alignment section and the bonding section. A light-emitting element transfer system including a stage module that includes a stage driving member for driving the aforementioned stage.

11. The light-emitting element transfer system according to claim 10, wherein the stage further includes a holding mechanism on its upper surface for preventing movement of the substrate or tray, and a protruding member that can protrude and retract.

12. The alignment section is, A holding member is positioned on top of the stage module and is used to support the second substrate on top of the first substrate by adsorbing or gripping the back surface of the second substrate. A second drive member that moves the holding member on a single plane, The light-emitting element transfer system according to claim 10, further comprising a vision member for capturing the alignment of the first substrate and the second substrate.

13. The bonding portion is, A pressure plate that transmits laser light, A support portion that supports the aforementioned pressure plate, A pressurizing drive unit that raises and lowers the aforementioned pressurizing plate in the vertical direction, The aforementioned pressure plate overlaps with a window positioned on the ceiling of the vacuum chamber, which transmits laser light and is located on the ceiling of the vacuum chamber. The light-emitting element transfer system according to claim 10, further comprising a laser member that emits laser light from the upper part of the window.

14. The light-emitting element transfer system according to claim 10, wherein the stage module further includes a first lifting member for raising and lowering the stage in a vertical direction.

15. The light-emitting element transfer system according to claim 12, wherein the alignment section further includes a second lifting member for raising and lowering the holding member in the vertical direction.

16. The second transport unit loads the first tray on which the first substrate is placed and the second tray on which the second substrate is placed into the vacuum chamber. The steps include: creating a vacuum inside the vacuum chamber, The first transport unit transports the first tray and the second tray to the alignment unit, The alignment unit aligns and bonds each of the multiple second substrates placed on the second tray to the first substrate placed on the first tray, The first transport unit transports the first tray on which the first substrate, which has been bonded to the second substrate, is placed to the bonding unit, The steps include: applying heat and pressure to the first substrate which has been bonded to the second substrate in the bonding section to bond the light-emitting elements arranged on the first substrate and the second substrate; A method for transferring a light-emitting element, comprising the step of breaking the vacuum atmosphere inside the vacuum chamber.

17. The step of transporting to the alignment unit is as follows: The method for transferring a light-emitting element according to claim 16, wherein the first tray is placed on the UVW stage of the alignment unit, and one of the plurality of second substrates placed on the second tray is adsorbed or grasped by a holding member.

18. The aforementioned step of aligning and joining is, The first tray is adsorbed onto the upper surface of the UVW stage using a holding mechanism, and the UVW stage is moved while the holding member is lowered to align the first tray and the second tray. The method for transferring a light-emitting element according to claim 17, further comprising the step of interrupting the adsorption or gripping of the second substrate by the holding member and adhering the second substrate to the first substrate.

19. The second transport unit loads the second tray, on which the first substrate and a plurality of second substrates are placed, into the vacuum chamber. The steps include: creating a vacuum inside the vacuum chamber, The first transport unit transports the first substrate and the second tray to the alignment unit, The alignment unit aligns and bonds each of the multiple second substrates placed on the second tray to the first substrate, one by one. The first transport unit transports the first substrate, which has been bonded with the second substrate, to the bonding unit, The steps include: applying heat and pressure to the first substrate which has been bonded to the second substrate in the bonding section to bond the light-emitting elements arranged on the first substrate and the second substrate; A method for transferring a light-emitting element, comprising the step of breaking the vacuum atmosphere inside the vacuum chamber.

20. The second transport unit loads the first tray on which the first substrate is placed and the second tray on which a plurality of second substrates are placed into the stage module of the vacuum chamber, The steps include: creating a vacuum inside the vacuum chamber, The stage module moves the stage to the alignment area, The holding member of the alignment unit adsorbs or grips one of the multiple second substrates placed on the second tray, The holding member of the alignment unit picks up or grips each of the multiple second substrates placed on the second tray, moves to the alignment area, and aligns and adheres the second substrates to the first substrate. The stage module transports the stage to the bonding area, The steps include: applying heat and pressure to the first substrate which is bonded to the second substrate in the bonding region to bond the light-emitting elements arranged on the first substrate and the second substrate; A method for transferring a light-emitting element, comprising the step of breaking the vacuum atmosphere inside the vacuum chamber.

21. The bonding step described above is The method for transferring a light-emitting element according to claim 20, wherein the stage generates heat from a built-in heater, the bonding section irradiates the first substrate with a laser, and the pressing member is lowered to apply pressure to the first substrate which is bonded to the second substrate.

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