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

Abstract

This provides technology related to a light-emitting element transfer apparatus. [Solution] One embodiment of this specification relates to a light-emitting element transfer apparatus and a transfer method, the light-emitting element transfer apparatus includes a vacuum chamber that creates or breaks a vacuum atmosphere inside, an alignment stage disposed inside the vacuum chamber and movable in three axes, a bonding stage disposed inside the vacuum chamber and movable vertically, a portable chuck having a built-in heater and selectively coupled to the alignment stage and the bonding stage, and a chuck holder coupled to the portable chuck and movable between the alignment stage and the bonding stage inside the vacuum chamber, wherein the portable chuck can be coupled to the chuck holder to chucking the upper surface of a first substrate, and can be separated from the chuck holder to dechucking the upper surface of the first substrate.

Description

Technical Field

[0001] The present invention relates to a light-emitting element transfer device 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 (Organic Light Emitting Display, OLED) and liquid crystal display devices (Liquid Crystal Display, LCD) 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 (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 1

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 device capable of performing an accurate alignment process and a bonding process within the same chamber.

[0007] The problems that the present invention will address are not limited to those described above, and any 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 apparatus according to one embodiment for solving the above problem includes a vacuum chamber that creates or destroys a vacuum atmosphere inside, an alignment stage disposed inside the vacuum chamber and movable in three axes, a bonding stage disposed inside the vacuum chamber and movable vertically, a portable chuck with a built-in heater that can be selectively coupled to the alignment stage and the bonding stage, and a chuck holder that is coupled to the portable chuck and can move between the alignment stage and the bonding stage inside the vacuum chamber, wherein the portable chuck can be coupled to the chuck holder to chucking the upper surface of the first substrate, and can be separated from the chuck holder to dechucking the upper surface of the first substrate.

[0009] The portable chuck may further include coupling members for coupling with the alignment stage and the bonding stage.

[0010] The coupling member includes a male coupler formed such that a portion of the built-in fastening member protrudes outward, and the alignment stage and the bonding stage may each have a groove-shaped female coupler formed on one surface at a position corresponding to the male coupler, which is coupled to the protruding male coupler.

[0011] The male coupler may be an air clamp, and the female coupler may be a locate ring corresponding to the air clamp.

[0012] The portable chuck may be an electrostatic chuck in which the substrate adheres due to the force of electrostatics.

[0013] The portable chuck includes a coupling projection, and the chuck holder includes a coupling groove into which the coupling projection is inserted and coupled, and the coupling projection and the coupling groove can be coupled and electrically connected.

[0014] The chuck holder can support at least a portion of the circumferential surface of the portable chuck such that the upper surface of the portable chuck is exposed.

[0015] The configuration may further include an upper chuck, which is positioned to overlap the alignment stage in the thickness direction, and to which a second substrate on which light-emitting elements are arranged is attached.

[0016] The upper chuck can chuck the second substrate and move up and down.

[0017] The light-emitting element transfer apparatus may further include a vision member for capturing images of the positions of the first and second substrates.

[0018] The light-emitting element transfer apparatus may further include a pressing member that is placed on the bonding stage and pressurizes the first substrate bonded to the second substrate placed on the bonding stage, and transmits laser light.

[0019] The light-emitting element transfer apparatus may further include a laser member that emits laser light onto a first substrate bonded to a second substrate placed on the bonding stage above the pressurizing member.

[0020] The vacuum chamber includes a chamber door located on one side, through which a first substrate or a second substrate can enter and exit the vacuum chamber.

[0021] The transfer method of a light-emitting element transfer device according to an embodiment includes the steps of arranging a first substrate on the upper surface of a chuck holder, coupling the chuck holder with a portable chuck so that the portable chuck chucks the first substrate, aligning a first substrate arranged on the portable chuck and a second substrate chucked by an upper chuck by an alignment stage coupled with the portable chuck, separating the upper chuck from the second substrate and attaching the first substrate and the second substrate together, and separating the portable chuck from the alignment stage, transporting the portable chuck onto a bonding stage by the chuck holder, coupling the portable chuck and the bonding stage, and performing a bonding process.

[0022] In the step of coupling the chuck holder with the portable chuck so that the portable chuck chucks the first substrate, a coupling protrusion of the portable chuck is inserted into a coupling groove of the chuck holder and coupled to each other, the coupling protrusion and the coupling groove are electrically connected, and an electrostatic force is generated in the electrostatic chuck of the portable chuck to chuck the first substrate.

[0023] In the step of separating the second substrate by the upper chuck and attaching the first substrate and the second substrate together, the upper chuck interrupts the adsorption or gripping of the second substrate, and the second substrate can be attached onto the first substrate.

[0024] A vision member can photograph the positions of the first substrate and the second substrate.

[0025] In the step of separating the portable chuck from the alignment stage, transporting the portable chuck onto the bonding stage by the chuck holder, coupling the portable chuck and the bonding stage, and performing a bonding process, the male coupler of the portable chuck is separated from the female coupler of the alignment stage, so that the portable chuck can be separated from the alignment stage.

[0026] When the portable chuck is separated from the alignment stage, the chuck holder transports the portable chuck onto the bonding stage, and the stage of coupling the portable chuck and the bonding stage and performing the bonding process is that, with the chuck holder coupled to the portable chuck, it moves along the transfer rail onto the bonding stage. When the portable chuck is brought closer to the bonding stage, the male coupler of the portable chuck can be coupled to the female coupler of the bonding stage.

[0027] The stage of performing the bonding process is that a pressing member presses the first substrate that is joined to the second substrate disposed on the portable chuck, electricity is applied to a heater incorporated in the portable chuck to generate heat in the heater, and heat is conducted to the portable chuck, whereby heat can be transferred to the first substrate or the joint between the first substrate and the second substrate.

Advantages of the Invention

[0028] The light-emitting element transfer device according to one embodiment can continuously perform the alignment process and the bonding process in a high-vacuum environment without opening the vacuum chamber, so that the production efficiency of the transfer device can be improved.

[0029] 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, that is, the display device, can be improved.

[0030] The effects according to the embodiment are not limited to the contents exemplified above, and more various effects are included in this specification.

Brief Description of the Drawings

[0031] [Figure 1] It 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 showing a light-emitting element transfer apparatus according to one embodiment. [Figure 6] This is a schematic side view showing a light-emitting element transfer apparatus according to one embodiment. [Figure 7] Figures 5 and 6 show enlarged views of the portable chuck, chuck holder, and alignment stage according to the embodiments. [Figure 8] Figures 5 and 6 show enlarged views of the portable chuck, chuck holder, and alignment stage according to the embodiments. [Figure 9] Figures 5 and 6 show enlarged views of the portable chuck, chuck holder, and bonding stage according to the embodiments. [Figure 10] Figures 5 and 6 show enlarged views of the portable chuck, chuck holder, and bonding stage according to the embodiments. [Figure 11] This figure shows the portable chuck 200 in an inverted state according to another embodiment. [Figure 12] This is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment. [Figure 13] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 14] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 15] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 16] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 17]This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 18] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 19] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 20] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Figure 21] This is a schematic diagram of a transfer apparatus for illustrating a method for transferring a light-emitting element according to one embodiment. [Modes for carrying out the invention]

[0032] 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.

[0033] 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.

[0034] The following describes specific embodiments with reference to the attached drawings.

[0035] 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.

[0036] 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).

[0037] 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 flat, but is not limited to this. For example, the display device 100 may include curved surfaces formed at the left and right sides, having a constant curvature or a changing curvature. The display device 100 can also be formed flexibly so that it can be bent, warped, folded, or rolled up.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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. For example, each subpixel may be an organic light-emitting element or a liquid crystal element.

[0046] 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 the same, 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 be different from the other one. Alternatively, any two of the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may be substantially the same, and the remaining one may be different from the other two. Alternatively, the areas of the first subpixel RP, the second subpixel GP, and the third subpixel BP may be different from each other.

[0047] Figure 4 is a cross-sectional view showing an example of a display panel cut along line A-A' in Figure 2.

[0048] 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.

[0049] 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.

[0050] 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).

[0051] A buffer film BF may be 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, selected from 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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).

[0056] 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.

[0057] 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 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).

[0058] 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.

[0059] 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 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.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] 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 materials or an alloy thereof: molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu).

[0065] 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.

[0066] 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 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.

[0067] 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.

[0068] 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).

[0069] 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, melts, and melts and mixes with the light-emitting element LE, the anode pad electrode APD, and the cathode pad electrode CPD, respectively, and then cools and solidifies when the laser supply is terminated. Even as the fused material 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 and physically connected to the light-emitting element LE. 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.

[0070] 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.

[0071] 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).

[0072] The base substrate SPUB may be a sapphire substrate, but the embodiments described herein are not limited thereto.

[0073] The n-type semiconductor NSEM is placed on one surface of the base substrate SPUB. For example, the n-type semiconductor NSEM may be placed on the bottom surface of the base substrate SPUB. The n-type semiconductor NSEM consists of GaN doped with n-type conductive dopants such as Si, Ge, and Sn.

[0074] 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.

[0075] 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.

[0076] Figure 5 is a schematic plan view showing a light-emitting element transfer apparatus according to one embodiment, and Figure 6 is a schematic side view showing a light-emitting element transfer apparatus according to one embodiment.

[0077] Referring to Figures 5 and 6, one embodiment of the light-emitting element transfer apparatus can align and bond a first substrate TS and a second substrate DS on which light-emitting elements are arranged, thereby bonding the light-emitting elements to the second substrate DS.

[0078] In this specification, the first substrate TS is a substrate onto which light-emitting elements are transferred, as the object to be processed by a light-emitting element transfer apparatus. The following description will focus on the case where the first substrate TS is a substrate for an inorganic light-emitting display device, as shown in Figure 4.

[0079] The second substrate DS is a substrate on which light-emitting elements are arranged, and serves as the object to be processed by the light-emitting element transfer apparatus. It is the substrate that provides light-emitting elements to the first substrate TS.

[0080] Specifically, the light-emitting element transfer apparatus may include a vacuum chamber VC, and a portable chuck 200, a chuck holder 250, an alignment section 300, and a bonding section 400, all of which are located within the vacuum chamber VC.

[0081] 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.

[0082] For example, a vacuum chamber VC can maintain a vacuum using a vacuum device that includes 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 VCD 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 are 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. Once the bonding process is complete, the vacuum atmosphere in the vacuum chamber VC can be broken. Vacuum generally refers to a state in which the pressure inside a space is lower than normal atmospheric pressure. Breaking the vacuum atmosphere means returning the inside of the space to a state other than a vacuum. For example, breaking the vacuum atmosphere could, but is not limited to, returning the inside of the vacuum chamber VC to normal atmospheric pressure.

[0083] A portable chuck 200, a chuck holder 250, an alignment unit 300, and a bonding unit 400 are arranged inside the vacuum chamber VC. Although parts of the alignment unit 300 and the bonding unit 400 are located outside the vacuum chamber VC, the alignment and bonding processes are performed within the same vacuum atmosphere in the 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 could lead to a decrease in alignment accuracy or hinder the transmission of applied pressure, are avoided.

[0084] The portable chuck 200 is positioned within the vacuum chamber VC and can be selectively coupled to the alignment stage 310 and the bonding stage 410. The portable chuck 200 can be coupled to a chuck holder 250 and move between the alignment section 300 and the bonding section 400. For example, the chuck holder 250 can move along a transport rail R positioned within the vacuum chamber VC.

[0085] The first substrate TS, lifted by a transport device such as a robotic arm, can be loaded into a portable chuck 200.

[0086] In a plan view, one surface of the portable chuck 200 has a larger area than one surface of the first substrate TS. One surface of the portable chuck 200 can completely cover the first substrate TS. For example, the diameter of the first substrate TS is approximately 300 nm, and the diameter of the portable chuck 200 may be between approximately 350 nm and 650 nm, but is not limited to this.

[0087] The portable chuck 200 is a chucking device for fixing a first substrate TS to one surface, and may be, for example, an electrostatic chuck. The electrostatic chuck adheres (bonds) to the first substrate TS by the force of electrostatics. When "+" and "-" are applied to the electrostatic chuck, the object is charged with opposite potentials ("-" and "+"), and the principle that an attractive force is generated by the charged potential is used to attach and fix the first substrate TS to the electrostatic chuck. Note that "chuck" and "chucking" mean that the main body is attached to or bonded to the object, or that the main body grasps the object. Also, "de-chuck" and "de-chucking" mean that the main body is released from the state of being attached to or bonded to the object, that the main body is separated from the object, or that the main body releases the object.

[0088] As shown in Figure 7, the portable chuck 200 is equipped with a built-in heater 200-h. The heater 200-h is configured to generate Joule heat, for example, as an electric heater. The heater conducts heat through the portable chuck 200, heating the first substrate TS supported by the portable chuck 200. By controlling the amount of heat generated by the heater, the temperature of the first substrate TS and its bonding surface can be adjusted.

[0089] The chuck holder 250 supports the portable chuck 200 such that its upper surface is exposed. For example, the chuck holder 250 may support the circumferential surface of the portable chuck 200 (e.g., both ends or edges). Alternatively, the chuck holder 250 may have an opening in the center.

[0090] The chuck holder 250 and the portable chuck 200 can be combined.

[0091] For example, the chuck holder 250 has a coupling groove 250-A, and the portable chuck 200 has a coupling projection 200-A. The coupling projection 200-A can be inserted into the coupling groove 250-A and coupled to each other. This couples the chuck holder 250 and the portable chuck 200. The coupling projection 200-A can be electrically connected when the coupling groove 250-A is coupled. The coupling projection 200-A and the coupling groove 250-A may contain conductors.

[0092] By applying electricity to the chuck holder 250, power is supplied to the portable chuck 200. Therefore, when the chuck holder 250 and the portable chuck 200 are coupled, the chuck function of the portable chuck 200 is activated, and the portable chuck 200 can chucking the first substrate TS. On the other hand, when the coupling between the chuck holder 250 and the portable chuck 200 is released, the chuck function is deactivated, and the portable chuck 200 can de-chucking the first substrate TS.

[0093] The portable chuck 200 may include a coupling member 200-c at its lower end. The coupling member 200-c may be coupled to the alignment stage 310 and the bonding stage 410.

[0094] Since the portable chuck 200 can move from the alignment stage 310 to the bonding stage 410 while supporting the first substrate TS bonded to the second substrate DS, if the first substrate TS bonded to the second substrate DS is moved as is, deflection will occur in the center of the first substrate TS bonded to the second substrate DS. This deflection increases in conjunction with the increase in the size of the first substrate TS bonded to the second substrate DS. This deflection may cause misalignment of the first substrate TS bonded to the second substrate DS. To prevent this, a carrier may be used, and the first substrate TS bonded to the second substrate DS may be placed on the carrier. In this case, deformation and changes in flatness of the carrier may occur due to the heat during the bonding process. This makes it difficult to reuse the carrier. Also, the deformed carrier may cause misalignment of the first substrate TS bonded to the second substrate DS.

[0095] The alignment unit 300 is a device for aligning and bonding the first substrate TS and the second substrate DS, and may include an alignment stage 310, an upper chuck 350, and a vision member 380. The alignment unit 300 may further include a lifting member 360 and a drive member 370 for driving the upper chuck 350. For this purpose, the first substrate TS and the second substrate DS may include alignment marks.

[0096] The upper chuck 350 is positioned on the ceiling of the vacuum chamber VC and is positioned to overlap with the alignment stage 310. The upper chuck 350 suctions or grips the back surface of the second substrate DS to support the second substrate DS on top of the first substrate TS during the alignment process. The upper chuck 350 may include a holding mechanism such as a vacuum suction system, a mechanical chuck, or an electrostatic chuck. For example, the upper chuck 350 may be an electrostatic chuck, but is not limited to that.

[0097] The alignment stage 310 may be a high-precision stage also known as a UVW stage. The UVW stage allows for position control in three axial directions: the U-axis, V-axis, and W-axis. The UVW stage includes linear motors installed in each of the U-axis, V-axis, and W-axis directions, and its position can be precisely controlled by individually controlling each linear motor. In one embodiment, a UVW stage that controls position in three axial directions (U-axis, V-axis, and W-axis) is shown, but the UVW stage is a concept that includes all alignment stages that can achieve desired position control by installing linear motors according to the required position control directions, such as the XYθ direction and the XY direction.

[0098] A linear motor is essentially a conventional rotary motor stretched axially. It generates linear motion directly through the attractive and repulsive forces between the electromagnetic field of the moving element and the permanent magnets (N / S poles) that make up the stator. Compared to conventional ball screws, linear motors have the advantages of less noise and wear, and enable precise handling.

[0099] Thus, the alignment stage 310 has high precision for positional alignment. 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 are instead performed on a separate stage 410.

[0100] The top surface of the alignment stage 310 is plate-shaped and can be connected to the portable chuck 200 as described above.

[0101] The portable chuck 200 is coupled with the alignment stage 310 to precisely align the first substrate TS, supported on the upper surface of the portable chuck 200, with the second substrate DS, attached to the upper chuck 350. Once the alignment is complete, the upper chuck 350 can separate the second substrate DS and bond it to the first substrate TS.

[0102] The lifting member 360 is positioned above the upper chuck 350 and can raise and lower the upper chuck 350. The lifting member 360 may include a lifting cylinder or the like.

[0103] The drive member 370 is positioned above the lifting member 360 and can move the upper chuck 350 up, down, left, and right on a single plane, or rotate it.

[0104] The vision member 380 recognizes alignment markers 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 lifting member 360, and the drive 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.

[0105] 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.

[0106] The bonding section 400 may include a bonding stage 410, a pressurizing member 440, and a laser member 450.

[0107] The bonding stage 410 can be coupled with the portable chuck 200 to support the portable chuck 200 during the bonding process. The bonding stage 410 is movable vertically. The bonding stage 410 may include drive members, such as a lifting cylinder. The bonding stage 410 can withstand greater pressure than the alignment stage 310.

[0108] The portable chuck 200, positioned on the bonding stage 410, heats the first substrate TS by generating heat via its built-in heater 200-h.

[0109] The pressurizing member 440 is positioned on the ceiling of the vacuum chamber VC and is positioned to overlap with the bonding stage 410. The pressurizing member 440 can pressurize the first substrate TS and the second substrate DS which are sequentially placed on the portable chuck 200.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] The transport member 600 may be a robot or the like, and is located outside the vacuum chamber VC. It can load the first substrate TS or the second substrate DS, which is loaded onto the cassette CS, onto the portable chuck 200 inside the vacuum chamber VC, or unload the first substrate TS, which has been bonded with the second substrate DS, inside the vacuum chamber VC.

[0115] Figures 7 and 8 are enlarged views of the portable chuck, chuck holder, and alignment stage according to the embodiments of Figures 5 and 6. Figure 7 is a diagram illustrating the state in which the portable chuck 200 and alignment stage 310 are separated, and Figure 8 is a diagram illustrating the state in which the portable chuck 200 and alignment stage 310 are combined.

[0116] Referring to Figure 7, the portable chuck 200 is coupled to the chuck holder 250. Therefore, the portable chuck 200 is coupled to the chuck holder 250 and receives electrical stimulation to chucking the first substrate TS.

[0117] The portable chuck 200 can be coupled with the alignment stage 310.

[0118] The portable chuck 200 may include a male coupler 200-C for coupling, and the alignment stage 310 may include a female coupler 300-C, but is not limited to this; the portable chuck 200 may also include a female coupler 300-C, and the alignment stage 310 may also include a male coupler 200-C.

[0119] In one embodiment, the male coupler 200-C may be an air clamp, and the female coupler 300-C may be a locate ring. An air clamp is, for example, a clamp that operates using compressed air. A clamp is a device that holds and fixes an object. A locate ring is, for example, a member used for alignment and coupling. Therefore, either the male coupler 200-C or the female coupler 300-C is formed to receive an air supply and can transition to a clamped state in which they are coupled and fixed to each other depending on the presence or absence of air supply. The above assumptions are for the convenience of explanation, and the present invention is not limited thereto.

[0120] In one embodiment, a fastening member can be formed on the air clamp corresponding to the male coupler 200-C, and a fastening groove can be formed on the locating ring corresponding to the female coupler 300-C.

[0121] When a fastening member is formed on the male coupler 200-C, an air passage may be formed in the male coupler 200-C so that it can receive an air supply. Therefore, each male coupler 200-C can be connected to a pneumatic control unit via the air passage. Thus, a pneumatic pressure above a certain level can be applied to the male coupler 200-C by the air supplied from the pneumatic control unit.

[0122] When the male coupler 200-C is formed on the portable chuck 200, an air passage connected to the male coupler 200-C can be formed at one point on the portable chuck 200 corresponding to the male coupler 200-C.

[0123] On the other hand, if the male couplers 200-C are formed on the portable chuck 200, female couplers 300-C can be formed on the alignment stage 310, which is connected to the portable chuck 200, at positions corresponding to each male coupler 200-C. As the portable chuck 200 approaches the alignment stage 310, the insertion portion C1 of each male coupler 200-C formed on the portable chuck 200 can be inserted into the insertion groove C2 of each female coupler 300-C formed on the alignment stage 310 as it moves.

[0124] When the air supplied to the male coupler 200-C along the air passage is blocked and the applied air pressure drops below a certain level, the blocking member that prevents the fastening member built into the insertion portion C1 of the male coupler 200-C, i.e., the air clamp, from protruding outward can be moved by the elastic force of an elastic body connected to the blocking member. As a result, the fastening member may move to a position corresponding to the through hole formed in the insertion portion C1 in accordance with the positional movement of the blocking member, and a part of the fastening member may protrude outward through the through hole.

[0125] As a result, as described above, when the insertion portion C1 of the male coupler 200-C is inserted into the insertion groove C2 of the female coupler 300-C, i.e., the locating ring, a part of the fastening member that protrudes outward catches in the fastening groove formed in the insertion groove C2, thereby coupling the insertion portion C1 and the insertion groove C2 with each other, and thereby transitioning to a clamped state in which the male coupler 200-C and the female coupler 300-C are coupled and fixed.

[0126] When air is again applied to the male coupler 200-C along the air passage, and the air pressure applied to the male coupler 200-C rises above a certain level again, the blocking member built into the insertion part C1 of the male coupler 200-C may move to its original position in accordance with the applied air pressure. This allows the blocking member to push out the fastening member. As a result, the fastening member can be moved inward. This causes the fastening member to fully retract into the interior of the male coupler 200-C, releasing the fastening caused by the engagement with the fastening groove, and releasing the connection between the insertion part C1 and the insertion groove C2. In other words, the clamped state in which the male coupler 200-C and the female coupler 300-C are connected and fixed can be released.

[0127] Thus, the air clamp, by utilizing the characteristic that it transitions to a clamped state or releases the clamped state when air is supplied from the pneumatic control unit or when the air supply is cut off, can, in one embodiment, be used to connect and fix the portable chuck 200 and the alignment stage 310, or to release the connection between the connected portable chuck 200 and the alignment stage 310.

[0128] A separate pneumatic control unit may be provided to connect and secure the portable chuck 200 and the alignment stage 310, or to release the connection between the connected stage and the base.

[0129] Referring to Figure 8, with the first substrate TS chucked, the insertion portion C1 of the air clamp, which is the male coupler 200-C of the portable chuck 200, is inserted into the insertion groove C2 of the locating ring, which is the female coupler 300-C of the alignment stage 310, transitioning to a clamped state, and the portable chuck 200 and the alignment stage 310 can be coupled.

[0130] This allows the portable chuck 200 and the first substrate TS on the portable chuck 200 to move in accordance with the alignment movement of the alignment stage 310.

[0131] Figures 9 and 10 are enlarged views of the portable chuck, chuck holder, and bonding stage according to the embodiments of Figures 5 and 6. Figure 9 is a diagram illustrating the state in which the portable chuck 200 and bonding stage 410 are separated, and Figure 10 is a diagram illustrating the state in which the portable chuck 200 and bonding stage 410 are joined together.

[0132] Referring to Figures 9 and 10, the portable chuck 200 is coupled to the chuck holder 250. Therefore, the portable chuck 200 is coupled to the chuck holder 250 and receives electrical stimulation to chucking the first substrate TS.

[0133] The portable chuck 200 can be coupled with the bonding stage 410.

[0134] The portable chuck 200 may include a male coupler 200-C for bonding, and the bonding stage 410 may include a female coupler 400-C, but is not limited to this; the portable chuck 200 may also include a female coupler 400-C, and the bonding stage 410 may also include a male coupler 200-C.

[0135] In one embodiment, the male coupler 200-C may be an air clamp and the female coupler 400-C may be a locating ring. Therefore, either the male coupler 200-C or the female coupler 400-C is formed to receive an air supply and, depending on the presence or absence of air supply, can transition to a clamped state in which they are coupled and fixed to each other. The following assumptions are for illustrative purposes only and the present invention is not limited thereto.

[0136] In one embodiment, a fastening member can be formed on the air clamp corresponding to the male coupler 200-C, and a fastening groove can be formed on the locating ring corresponding to the female coupler 400-C.

[0137] When male couplers 200-C are formed on the portable chuck 200, female couplers 400-C may be formed on the bonding stage 410, which is connected to the portable chuck 200, at positions corresponding to each male coupler 200-C. As the portable chuck 200 approaches the bonding stage 410, the insertion portion C1 of each male coupler 200-C formed on the portable chuck 200 can be inserted into the insertion groove C2 of each female coupler 400-C formed on the bonding stage 410 as it moves.

[0138] As described with reference to Figures 7 and 8, the air clamp has the characteristic that it transitions to a clamped state or is released when air is supplied from the pneumatic control unit or when the air supply is cut off, and in one embodiment, it can be used to connect and fix the portable chuck 200 and the bonding stage 410, or to release the connected state of the portable chuck 200 and the bonding stage 410.

[0139] A separate pneumatic control unit is provided to connect and secure the portable chuck 200 and the bonding stage 410, or to release the connection between the connected stage and the base.

[0140] Referring to Figure 10, with the first substrate TS chucked, the insertion part C1 of the air clamp, which is the male coupler 200-C of the portable chuck 200, is inserted into the insertion groove C2 of the locating ring, which is the female coupler 400-C of the bonding stage 410, transitioning to a clamped state, thereby coupling the portable chuck 200 and the bonding stage 410.

[0141] The bonding stage 410 can support the first substrate TS bonded to the second substrate DS while pressure is applied to the first substrate TS bonded to the second substrate DS, which is placed on the portable chuck 200, during the bonding process.

[0142] Figure 11 shows the inverted state of the portable chuck 200 according to another embodiment.

[0143] Referring to Figure 11, the portable chuck 200 can chuck a first substrate TS (or a first substrate TS bonded to a second substrate DS) which is arranged on one surface in conjunction with the chuck holder 250 as described above.

[0144] The chuck holder 250 inverts the portable chuck 200. In one embodiment, the portable chuck 200 can be inverted so that the front of the portable chuck 200, which is placed on the bonding stage 410, faces downwards towards the bonding stage 410, and the rear of the portable chuck 200 faces upwards.

[0145] In this way, when the portable chuck 200 is in the chucking state, the first substrate TS can be fixed to one side of the portable chuck 200 even if the portable chuck 200 is inverted.

[0146] Figure 12 is a flowchart illustrating a method for transferring light-emitting elements using a transfer apparatus according to one embodiment. Figures 13 and 21 are schematic diagrams of a transfer apparatus illustrating a method for transferring light-emitting elements using one embodiment. Figures 13 to 20 may be the transfer apparatus described with reference to Figures 5 to 10.

[0147] First, the first substrate TS is placed on the upper surface of the chuck holder 250 (S110 in Figure 12).

[0148] Referring to Figures 13 and 14, the first substrate TS is placed on the chuck holder 250 by a transport member 600 such as a robot. The chuck holder 250 supports at least a portion of the edge of the first substrate TS. When the chuck holder 250 supports at least a portion of the edge of the first substrate TS, the center of the first substrate TS may bend downward due to its own weight.

[0149] Referring to Figure 15, the first substrate TS is positioned on the upper surface of the portable chuck 200. The portable chuck 200 is coupled to the alignment stage 310.

[0150] Referring to Figure 16, the portable chuck 200 and the chuck holder 250 are connected. The connecting groove 250-A of the chuck holder 250 and the connecting projection 200-A of the portable chuck 200 can connect with each other. As a result, the portable chuck 200 can chucking the first substrate TS.

[0151] Next, the first substrate TS and the second substrate DS are aligned and bonded together (S120 in Figure 12).

[0152] Referring to Figure 16, it can be seen that the first substrate TS and the second substrate DS are aligned and bonded together. For example, the upper chuck 350 fixes the back surface of the second substrate DS. At this time, the light-emitting elements placed on the second substrate DS can be positioned to face the first substrate TS.

[0153] The alignment marks on the first substrate TS and the second substrate DS are checked using the vision component (380 in Figure 6), and the alignment stage 310 is moved based on the alignment marks to align the first substrate TS and the second substrate DS.

[0154] Subsequently, referring to Figure 17, the first substrate TS and the second substrate DS are joined together, and the upper chuck 350 is de-chucking to release the fixing of the second substrate DS, thereby separating the second substrate DS from the upper chuck 350.

[0155] Next, the portable chuck 200 is moved to the bonding stage 410 (S130 in Figure 12).

[0156] For example, referring to Figure 18, the portable chuck 200 is separated from the alignment stage 310 by releasing the coupling with the air clamp. The portable chuck 200 remains coupled to the chuck holder 250. This allows the portable chuck 200 to continue holding the first substrate TS in place.

[0157] Referring to Figure 19, the portable chuck 200 moves along the transport rail onto the bonding stage 410 in the same chamber, with the first substrate TS fixed in place.

[0158] Next, the portable chuck 200 and the bonding stage 410 are connected, and the bonding process is performed (S140 in Figure 12).

[0159] Referring to Figure 20, when the portable chuck 200 is brought close to the upper surface of the bonding stage 410, the male coupler 200-C of the portable chuck 200 can be coupled with the female coupler 400-C of the bonding stage 410.

[0160] Subsequently, a bonding process may be performed. For example, a pressing member 440 can pressurize the first substrate TS and the second substrate DS which are sequentially placed on the portable chuck 200.

[0161] By applying electricity to the heater 200-h built into the portable chuck 200, the heater 200-h generates heat, and the heat is conducted to the portable chuck 200, thereby transferring heat to the first substrate TS or the junction between the first substrate TS and the second substrate DS.

[0162] 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. The laser emitted from the laser member 450 can pass through the pressurizing member 440 and irradiate 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.

[0163] 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.

[0164] During the bonding process, the bonding stage 410 can secure and support the portable chuck 200.

[0165] Subsequently, once the bonding process is complete, the portable chuck 200 is released from the bonding stage 410, as shown in Figure 21, and the vacuum chamber VC can be released from its vacuum.

[0166] The first substrate TS, bonded to the second substrate DS, can be transported while placed on the portable chuck 200. Therefore, the portable chuck 200 can also function as a carrier or tray.

[0167] 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]

[0168] 100 display device VC Vacuum Chamber TS 1st board DS 2nd board 200 Loading section 300 Alignment Section 310 Alignment Stages 400 Bonding section 410 Bonding Stage 600 Conveyor System CS Cassette

Claims

1. A vacuum chamber that creates or breaks a vacuum atmosphere inside, An alignment stage, which is located inside the vacuum chamber and is movable in three axes, A bonding stage, which is positioned inside the vacuum chamber and is movable vertically, A portable chuck with a built-in heater that can be selectively coupled to the alignment stage and the bonding stage, The portable chuck is coupled to a chuck holder that is movable between the alignment stage and the bonding stage inside the vacuum chamber, The portable chuck is coupled with the chuck holder to chucking the upper surface of the first substrate, and is separated from the chuck holder to dechucking the upper surface of the first substrate, in a light-emitting element transfer apparatus.

2. The light-emitting element transfer apparatus according to claim 1, wherein the portable chuck further includes a coupling member for coupling with the alignment stage and the bonding stage.

3. The coupling member includes a male coupler formed such that a portion of the built-in fastening member protrudes to the outside. The light-emitting element transfer apparatus according to claim 2, wherein the alignment stage and the bonding stage each have a groove-shaped female coupler formed on one surface at a position corresponding to the male coupler and coupled to the protruding male coupler.

4. The aforementioned male coupler is an air clamp. The light-emitting element transfer apparatus according to claim 3, wherein the female coupler is a locate ring corresponding to the air clamp.

5. The light-emitting element transfer apparatus according to claim 1, wherein the portable chuck is an electrostatic chuck on which the substrate adheres due to the force of electrostatics.

6. The portable chuck includes a connecting projection, The chuck holder includes a coupling groove into which the coupling projection is inserted and coupled. The light-emitting element transfer apparatus according to claim 1, wherein the coupling projection and the coupling groove are coupled and electrically connected.

7. The light-emitting element transfer apparatus according to claim 1, wherein the chuck holder supports at least a portion of the circumferential surface of the portable chuck such that the upper surface of the portable chuck is exposed.

8. The light-emitting element transfer apparatus according to claim 1, further comprising an upper chuck arranged to overlap the alignment stage in the thickness direction, to which a second substrate on which light-emitting elements are arranged is attached.

9. The light-emitting element transfer apparatus according to claim 8, wherein the upper chuck is capable of chucking the second substrate and moving up and down.

10. The light-emitting element transfer apparatus according to claim 8, further comprising a vision member for capturing images of the positions of the first substrate and the second substrate.

11. A pressing member is placed on the bonding stage and pressurizes the first substrate bonded to the second substrate placed on the bonding stage, and transmits laser light. The light-emitting element transfer apparatus according to claim 1, further comprising a laser member that emits laser light onto a first substrate bonded to a second substrate placed on the bonding stage at the upper part of the pressurizing member.

12. The light-emitting element transfer apparatus according to claim 1, wherein the chuck holder inverts the portable chuck.

13. The vacuum chamber includes a chamber door located on one side. The light-emitting element transfer apparatus according to claim 1, wherein the first substrate or the second substrate enters and exits the vacuum chamber through the chamber door.

14. The step of placing the first substrate on the upper surface of the chuck holder, The steps include: connecting the chuck holder with the portable chuck so that the portable chuck chucking the first substrate; The alignment stage coupled with the portable chuck aligns the first substrate placed on the portable chuck and the second substrate chucked by the upper chuck, and the upper chuck separates the second substrate and joins the first substrate and the second substrate together. A method for transferring a light-emitting element, comprising the steps of separating the portable chuck from the alignment stage, transporting the portable chuck onto a bonding stage by a chuck holder to connect the portable chuck and the bonding stage, and performing a bonding process.

15. The step of connecting the chuck holder with the portable chuck so that the portable chuck chucking the first substrate is as follows: The method for transferring a light-emitting element according to claim 14, wherein the coupling projection of the portable chuck is inserted into the coupling groove of the chuck holder and coupled to each other, the coupling projection and the coupling groove are electrically connected, and an electrostatic force is generated in the electrostatic chuck of the portable chuck to chucking the first substrate.

16. In the step where the upper chuck separates the second substrate and joins the first substrate and the second substrate, The method for transferring a light-emitting element according to claim 14, wherein the upper chuck interrupts the adsorption or gripping of the second substrate and causes the second substrate to adhere to the first substrate.

17. The method for transferring a light-emitting element according to claim 16, wherein the vision member photographs the positions of the first substrate and the second substrate.

18. In the stage where the portable chuck is separated from the alignment stage, the chuck holder transports the portable chuck onto the bonding stage, the portable chuck and the bonding stage are connected, and the bonding process is performed, The method for transferring a light-emitting element according to claim 14, wherein the male coupler of the portable chuck is separated from the female coupler of the alignment stage, thereby separating the portable chuck from the alignment stage.

19. The steps include: separating the portable chuck from the alignment stage, transporting the portable chuck onto the bonding stage by the chuck holder, connecting the portable chuck and the bonding stage, and performing the bonding process; The method for transferring a light-emitting element according to claim 18, wherein the chuck holder is moved along a transport rail onto the bonding stage while coupled with the portable chuck, and when the portable chuck is brought closer to the bonding stage, the male coupler of the portable chuck is coupled with the female coupler of the bonding stage.

20. The step of performing the bonding process is: The pressurizing member pressurizes the first substrate, which is bonded to the second substrate placed on the portable chuck. A method for transferring a light-emitting element according to claim 19, wherein electricity is applied to a heater containing a portable chuck to heat the heater, and heat is conducted to the portable chuck, thereby transferring heat to the first substrate or the junction between the first substrate and the second substrate.

Images