Pushing jig and transfer device

Abstract

Provided is a pressing jig or a transfer device that can suppress a temperature rise caused by laser irradiation. The pressing jig is a pressing jig that presses a component substrate provided with an LED element against a circuit substrate provided with a pixel circuit that drives the LED element; the pressing jig includes: a plate-like member that allows the laser irradiated to the LED element to pass through; and a cooling unit that cools the plate-like member. The transfer device includes: a stage that mounts a circuit substrate provided with a pixel circuit that drives the LED element; a laser irradiation unit that irradiates the LED element with laser; and a pressing jig that includes a plate-like member that allows the laser to pass through and a cooling unit that cools the plate-like member, and presses the component substrate provided with the LED element against the circuit substrate.

Description

Technical Field

[0001] The present invention relates to a transfer device for transferring LED (Light Emitting Diode) elements. In addition, the present invention relates to a pressing jig used in the transfer device. Background Art

[0002] In recent years, as a next-generation display device, the development of a micro-LED display in which minute LED elements are installed in each pixel has been promoted. The micro-LED display has a structure in which a plurality of LED elements are mounted on a circuit board on which a pixel circuit is formed.

[0003] Among the methods for mounting micro-LED elements on a circuit board, there are various methods. For example, there is known a method called a so-called laser lift-off method in which an element substrate provided with micro-LED elements and a circuit board are brought into close contact with each other and a laser is irradiated to transfer the micro-LED elements from the element substrate to the circuit board (for example, refer to Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Specification of U.S. Patent No. 10096740 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] In Patent Document 1, a laser is irradiated using a light-shielding mask during laser lift-off, but the light-shielding mask absorbs the laser, and there is a problem of temperature rise of the light-shielding mask. In addition, not only the light-shielding mask but also the element substrate and the circuit board absorb the laser, and there is also a problem of damage caused by heat of the micro-LED elements.

[0009] One object of the present invention is to provide a transfer device capable of suppressing temperature rise caused by laser irradiation during laser lift-off of LED elements. In addition, one object of the present invention is to provide a pressing jig capable of suppressing temperature rise caused by laser irradiation.

[0010] Means for Solving the Problems

[0011] A pressing jig according to one aspect of the present invention is a pressing jig that presses an element substrate provided with LED elements against a circuit board provided with a pixel circuit for driving the LED elements, the pressing jig including: a plate-like member that allows laser light irradiated onto the LED elements to pass through; and a cooling unit that cools the plate-like member.

[0012] In addition, a transfer device according to one aspect of the present invention includes: a stage on which a circuit board provided with a pixel circuit for driving an LED element is placed; a laser irradiation unit that irradiates the LED element with laser; and a pressing jig that includes a plate-like member through which the laser passes and a cooling unit that cools the plate-like member, and presses an element substrate provided with the LED element against the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic view of a transfer device according to an embodiment of the present invention.

[0014] Figure 2A It is a schematic perspective view of a pressing jig of a transfer device according to an embodiment of the present invention.

[0015] Figure 2B It is a schematic top view of a pressing jig of a transfer device according to an embodiment of the present invention.

[0016] Figure 3 It is a flowchart showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0017] Figure 4A It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0018] Figure 4B It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0019] Figure 4C It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0020] Figure 4D It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0021] Figure 4E It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0022] Figure 4F It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0023] Figure 4G It is a schematic cross-sectional view showing a method for transferring an LED element using a transfer device according to an embodiment of the present invention.

[0024] Figure 5 It is a top view showing the schematic structure of a display device manufactured using a transfer device according to an embodiment of the present invention.

[0025] Figure 6 It is a block diagram showing the circuit structure of a display device manufactured using a transfer device according to an embodiment of the present invention.

[0026] Figure 7 It is a circuit diagram showing the structure of a pixel circuit of a display device manufactured using a transfer device according to an embodiment of the present invention.

[0027] Figure 8 It is a cross-sectional view showing the structure of a pixel of a display device manufactured using a transfer device according to an embodiment of the present invention.

[0028] Figure 9A It is a schematic perspective view of a pressing jig according to an embodiment of the present invention.

[0029] Figure 9B It is a schematic cross-sectional view of a pressing jig according to an embodiment of the present invention.

[0030] Figure 10A It is a schematic perspective view of a pressing jig according to an embodiment of the present invention.

[0031] Figure 10B It is a schematic cross-sectional view of a pressing jig according to an embodiment of the present invention.

[0032] Figure 11A It is a schematic perspective view of a pressing jig according to an embodiment of the present invention.

[0033] Figure 11B It is a schematic cross-sectional view of a pressing jig according to an embodiment of the present invention.

[0034] Reference Numeral Explanation

[0035] 10: Transfer device; 20: Display device; 20a: Display area; 20b: Peripheral area; 20c: Terminal area; 100: Stage; 200, 200A, 200B, 200C: Pushing jig; 210, 210C: Plate-like member; 211C: Inlet hole; 212C: Outlet hole; 213C: Flow path; 220, 220A, 220B: Heat sink; 221A: Inlet hole; 222A: Outlet hole; 223A: Flow path; 230: Transmissive area; 300: Laser irradiation unit; 310: First laser; 320: Second laser; 400: Light-shielding mask; 400a: Opening; 800: Component substrate; 810: Semiconductor substrate; 820, 820B, 820G, 820R: LED element; 830, 830a, 830b, 830R: Terminal electrode; 900: Circuit substrate; 910: Support substrate; 920, 920B, 920G, 920R: Pixel circuit; 921: Data line; 922: Gate line; 923: Anode power line; 924: Cathode power line; 926: Selection transistor; 927: Driving transistor; 927a: Semiconductor layer; 927b: Gate insulating layer; 927c: Gate electrode; 927d: Insulating layer; 927e: Source electrode; 927f: Drain electrode; 928: Holding capacitor; 930: Connection electrode; 930a: Connection electrode; 940: Alloy layer; 950, 950B, 950G, 950R: Pixel; 961: Wiring; 962: Planarization layer; 963: Connection wiring; 964: Insulating layer; 965: Anode electrode; 966: Cathode electrode; 967: Planarization layer; 968a, 968b: Mounting pad; 1010: Flexible printed circuit board (FPC); 1020: IC chip; 1030: Data driver circuit; 1040: Gate driver circuit; 1050: Terminal portion; 1051: Connection wiring; 1052: Connection wiring. Detailed implementation mode

[0036] Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in various forms without departing from its gist. The present invention is not construed as being limited to the content described in the embodiments exemplified below. The drawings schematically show the widths, thicknesses, shapes, etc. of each part compared with the actual form for the sake of clearer explanation. However, the drawings are merely examples and do not limit the interpretation of the present invention.

[0037] When describing the embodiments of the present invention, the direction from the circuit board toward the LED element is defined as "up", and the opposite direction is defined as "down". However, the expressions "up" or "down" merely illustrate the upper and lower relationships of the respective elements. For example, the expression that the LED element is disposed above the circuit board also includes the case where other components are interposed between the circuit board and the LED element. Further, the expressions "up" or "down" include not only the case where the respective elements overlap in a top view but also the case where they do not overlap.

[0038] When describing the embodiments of the present invention, for elements having the same functions as the elements already described, there are cases where the same reference numerals are given or marks such as Latin letters are given to the same reference numerals to omit the description. In addition, when it is necessary to distinguish each color of RGB for a certain element, marks of R, G, or B are given after the reference numeral indicating the element to make the distinction. However, when it is not necessary to distinguish each color of RGB for the element, only the reference numeral indicating the element is used for the description.

[0039] <First Embodiment>

[0040] [1. Structure of Transfer Device 10]

[0041] Refer to Figures 1 to 2B , and a transfer device 10 according to an embodiment of the present invention will be described. Figure 1 is a schematic diagram of a transfer device 10 according to an embodiment of the present invention. In addition, Figure 2A and Figure 2B are respectively a schematic perspective view and a top view of a pressing jig 200 of the transfer device 10 according to an embodiment of the present invention.

[0042] As Figure 1 shown, the transfer device 10 includes a stage 100, a pressing jig 200, a laser irradiation unit 300, and a light-shielding mask 400. The pressing jig 200 is disposed above the stage 100. In addition, the laser irradiation unit 300 is disposed above the pressing jig 200. However, the arrangement of the laser irradiation unit 300 is not limited thereto. The laser irradiation unit 300 may have a structure capable of irradiating laser light from above the pressing jig 200. The light-shielding mask 400 is disposed between the stage 100 and the pressing jig 200.

[0043] The stage 100 supports the circuit board 900 that houses the pixel circuits for driving the LED elements. Therefore, the stage 100 has a flat surface for placing the circuit board 900. For example, the circuit board 900 is a glass substrate or a flexible resin substrate. Pixel circuits are formed by a plurality of TFTs (Thin Film Transistors) on the glass substrate or the resin substrate, and the circuit board 900 may also be referred to as the TFT substrate 900. Although details will be described later, when transferring the LED elements, the element substrate 800 with the LED elements is placed on the circuit board 900.

[0044] The pressing jig 200 presses the element substrate 800 so that the LED elements on the element substrate 800 are in close contact with the circuit board 900 on the stage 100. More specifically, after the light-shielding mask 400 is disposed on the element substrate 800, the pressing jig 200 can press and hold the element substrate 800 via the light-shielding mask 400. The pressing jig 200 may also be pressed by an external force to press the element substrate 800. In addition, the pressing jig 200 may be provided with a pressure sensor so as to be able to detect the pressing force.

[0045] As Figure 2A and Figure 2B shown, the pressing jig 200 includes a plate-like member 210 and a heat sink 220. The plate-like member 210 allows laser light of a specified wavelength irradiated from the laser irradiation unit 300 to pass through. As the plate-like member 210, for example, quartz glass or the like can be used. The heat sink 220 is provided in contact with the peripheral portion of the plate-like member 210. In other words, the heat sink 220 is provided around the laser-transmitting area 230 irradiated with the laser. The heat sink 220 can absorb or dissipate the heat of the plate-like member 210. That is, the heat sink 220 can function as a cooling unit for cooling the plate-like member 210. As the heat sink 220, for example, a metal material such as aluminum, iron, or copper, or a metal material with a high thermal conductivity such as an alloy material containing these metal materials can be used.

[0046] The heat sink 220 has a plurality of protrusions (fins). Figure 2A As shown, the shape of the fins of the heat sink 220 is flat, but the shape of the fins is not limited to this. As long as the shape of the fins is such that the surface area of the heat sink 220 increases. For example, the shape of the fins may also be a pincushion shape or a corrugated shape.

[0047] A fan may also be provided on the heat sink 220. By rotating the fan, the air around the heat sink 220 is made to convect, and the heat dissipation efficiency of the heat sink 220 is improved.

[0048] The laser irradiation unit 300 irradiates a laser on the LED element through the transmission area 230 of the pressing jig 200. The laser irradiation unit 300 can irradiate two types of lasers with different wavelengths. As will be described in detail later, the laser irradiation unit 300 can irradiate a first laser having a wavelength in the infrared region or near-infrared region and a second laser having a wavelength in the ultraviolet region. As the light source of the first laser, a solid laser such as a YAG laser or a YVO4 laser can be used. In addition, as the light source of the second laser, a solid laser such as a YAG laser or a YVO4 laser, or an excimer laser or the like can be used.

[0049] The laser irradiation unit 300 can either scan the laser to irradiate a plurality of LED elements or divide the laser into a plurality of parts to irradiate a plurality of LED elements simultaneously. In addition, the laser irradiation unit 300 can also form the laser into a linear shape or a rectangular shape to irradiate a plurality of LED elements simultaneously.

[0050] The light-shielding mask 400 includes a region (such as an opening) that allows the laser to pass through and a region that shields the laser. Therefore, adjustment can be made through the light-shielding mask 400 so that the laser is irradiated only on the specified LED elements of the element substrate 800.

[0051] In addition, although not shown, the transfer device 10 may also include a transfer unit that transports the element substrate 800 or the circuit substrate 900 onto the stage 100. In addition, the transfer device 10 may also include an adjustment unit that adjusts the positions of the element substrate 800 and the circuit substrate 900.

[0052] [2. Transfer Method of LED Elements by Transfer Device 10]

[0053] Refer to Figures 3 to 4G , and a transfer method of LED elements using the transfer device 10 according to an embodiment of the present invention will be described. Figure 3 is a flowchart showing a transfer method of LED elements using the transfer device 10 according to an embodiment of the present invention. Figures 4A to 4G is a schematic cross-sectional view showing a transfer method of LED elements using the transfer device 10 according to an embodiment of the present invention.

[0054] In Figure 3 step S100 of, the circuit substrate 900 is placed on the stage 100 (refer to Figure 4A)。The circuit board 900 is on a support board 910 with an insulating surface, and is formed with a plurality of pixel circuits 920 that drive LED elements respectively and connection electrodes 930 connected to the pixel circuits 920. As the support board 910, a glass board, a resin board, a ceramic board, a metal board, etc. can be used. The pixel circuit is formed by a TFT formed on the support board. The connection electrode 930 is formed corresponding to the structure of the mounted LED element. As the connection electrode 930, a conductive metal material such as tin (Sn) can be used. The thickness of the connection electrode 930 is 0.2 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less. In addition, the structure of the circuit board 900 and the details of the pixel circuit 920 will be described later.

[0055] In Figure 3 step S200 of, the element substrate 800 is placed on the circuit board 900 in such a manner that the connection electrode 930 of the circuit board 900 faces the LED element 820R of the element substrate 800 (refer to Figure 4B ). The element substrate 800 is a substrate having a plurality of LED elements 820R that emit red light provided on a semiconductor substrate 810. As the semiconductor substrate 810, a sapphire substrate, etc. can be used. The LED element 820R includes a semiconductor material such as gallium nitride grown on the sapphire substrate. The semiconductor material can be appropriately determined according to the emission color.

[0056] The terminal electrode 830R of the LED element 820R overlaps with the connection electrode 930 corresponding to the pixel of red among the plurality of connection electrodes 930. At this time, the element substrate 800 can also be temporarily fixed by providing an adhesive layer (not shown) between each connection electrode 930 and each terminal electrode 830R.

[0057] In addition, in the above, the structure in which the LED element 820R is provided on the semiconductor substrate 810 is described, but the LED element 820R can also be provided on a glass substrate or a resin substrate. That is, the LED element 820R can also be transferred with a glass substrate or a resin substrate as a carrier substrate.

[0058] In Figure 3 step S300 of, the light-shielding mask 400 is arranged on the element substrate 800 (refer to Figure 4C ). The light-shielding mask 400 has a plurality of openings 400a. The plurality of openings 400a are arranged, for example, to match the pitch (interval between pixels) of the pixels corresponding to red, the pixels corresponding to green, or the pixels corresponding to blue. In Figure 4C , the opening 400a overlaps with the position where the LED element 820R is arranged.

[0059] In Figure 3In step S400, the pressing jig 200 is disposed on the photomask 400, and the element substrate 800 is pressed via the photomask 400 (refer to Figure 4D ). Thereby, the terminal electrode 830R of the LED element 820R can be reliably brought into close contact with the connection electrode 930. In addition, by the pressing of the pressing jig 200, the plate-like member 210 of the pressing jig 200, the photomask 400, and the element substrate 800 are brought into close contact with each other.

[0060] In Figure 3 step S500, the laser irradiation unit 300 irradiates the first laser 310 onto the LED element 820, and joins the connection electrode 930 and the LED element 820R together (refer to Figure 4E ). This process is a process of fusion-joining the connection electrode 930 and the terminal electrode 830R by the irradiation of the first laser 310. In addition, the first laser 310 passes through the through region 230 of the pressing jig 200 and the opening 400a of the photomask 400, and is irradiated onto the terminal electrode 830 of the LED element 820.

[0061] As described above, the first laser 310 has a wavelength in the infrared region or the near-infrared region and is absorbed by the terminal electrode 830 or the connection electrode 930. By the irradiation of the first laser 310, an alloy layer 940 made of a eutectic alloy is formed between the connection electrode 930 and the terminal electrode 830R. As described above, the connection electrode 930 is made of tin (Sn). On the other hand, the terminal electrode 830R is made of gold (Au). That is, as the alloy layer 940, a layer made of a Sn-Au eutectic alloy is formed. However, as the connection electrode 930 and the terminal electrode 830R, other metal materials may be used as long as they can form a eutectic alloy with each other.

[0062] By forming the alloy layer 940 made of a eutectic alloy between the connection electrode 930 and the terminal electrode 830R, the connection electrode 930 and the terminal electrode 830R are joined via the alloy layer 940. As a result, the LED element 820R can be firmly mounted on the connection electrode 930.

[0063] In Figure 3 step S600, the laser irradiation unit 300 irradiates the second laser 320 onto the LED element 820, and separates the semiconductor substrate 810 and the LED element 820R together (refer to Figure 4F ). This process is a so-called laser lift-off process. Specifically, it is a process of modifying the boundary portion between the semiconductor substrate 810 and the plurality of LED elements 820R by the irradiation of the second laser 320 and separating the plurality of LED elements 820R from the semiconductor substrate 810.

[0064] As described above, the second laser 320 has a wavelength in the ultraviolet region and is absorbed by the LED element 820. By irradiating the second laser 320, the surface layer portion (the boundary portion with the semiconductor substrate 810) of the LED element 820R is modified, and the semiconductor substrate 810 and the LED element 820R are separated.

[0065] After irradiating the second laser 320, the semiconductor substrate 810 and each LED element 820R are separated. Through the above processing, as Figure 4G shown, the LED element 820R can be mounted on the circuit board 900.

[0066] After obtaining the Figure 4G state shown, the steps S200 to S600 shown are repeatedly performed, and the LED element 820G that emits green light and the LED element 820B that emits blue light are sequentially mounted on the circuit board 900. Figure 3

[0067] Due to the irradiation of the first laser 310 in step S500 and the irradiation of the second laser 320 in step S600, the temperatures of the light-shielding mask 400, the element substrate 800, and the circuit board 900 may rise. However, in the present embodiment, a cooling portion (heat sink 220) is provided on the pressing jig 200. By pressing and being in close contact with the plate-like member 210, the light-shielding mask 400, the element substrate 800, and the circuit board 900, the heat of the light-shielding mask 400, the element substrate 800, and the circuit board 900 is conducted to the plate-like member 210, and the heat sink 220 can absorb or dissipate the heat conducted to the plate-like member 210. Therefore, the pressing jig 200 can suppress the temperature rise of the light-shielding mask 400, the element substrate 800, and the circuit board 900. Thus, in the transfer device 10 including the pressing jig 200, the temperature rise of the light-shielding mask 400, the element substrate 800, and the circuit board 900 can be suppressed, so that the accuracy of transferring the LED element 820 to a specified position is improved. In addition, the damage to the LED element 820 or the circuit board 900 caused by heat can be reduced.

[0068] [3. Structure of the display device 20]

[0069] With reference to Figures 5 to 8 , the display device 20 manufactured using the transfer device 10 according to an embodiment of the present invention will be described.

[0070] [3-1. Outline of the structure of the display device 20]

[0071] Figure 5 is a schematic top view showing the structure of the display device 20 manufactured using the transfer device 10 according to an embodiment of the present invention. As Figure 5As shown, the display device 20 includes a circuit board 900, a flexible printed circuit board 1010 (FPC 1010), and an IC chip 1020. In addition, the display device 20 is divided into a display area 20a, a peripheral area 20b, and a terminal area 20c.

[0072] The display area 20a is an area where a plurality of pixels including LED elements 820 are arranged in the row direction (D1 direction) and the column direction (D2 direction). Specifically, in the display area 20a, pixels 950R including LED element 820R, pixels 950G including LED element 820G, and pixels 950B including LED element 820B are arranged. The display area 20a functions as an area for displaying an image corresponding to an image signal.

[0073] The peripheral area 20b is an area around the display area 20a. The peripheral area 20b is provided with a driver circuit ( Figure 6 the data driver circuit 1030 and the gate driver circuit 1040 shown) for controlling the pixel circuits 920 provided in each pixel 950.

[0074] The terminal area 20c is an area where a plurality of wirings connected to the driver circuit are integrated. The flexible printed circuit board 1010 is electrically connected to the plurality of wirings in the terminal area 20c. An image signal (data signal) or a control signal output from an external device (not shown) is input to the IC chip 1020 via a wiring (not shown) provided in the flexible printed circuit board 1010. The IC chip 1020 performs signal processing on the image signal or generates a control signal required for display control. The image signal and the control signal output from the IC chip 1020 are input to the display device 20 via the flexible printed circuit board 1010.

[0075] [3-2. Circuit Structure of Display Device 20]

[0076] Figure 6 is a block diagram showing the circuit structure of the display device 20 manufactured using the transfer device 10 according to an embodiment of the present invention. As Figure 6 shown, in the display area 20a, a plurality of pixel circuits 920 are provided in the row direction (D1 direction) and the column direction (D2 direction) corresponding to each pixel 950. That is, pixel circuits 920R, pixel circuits 920G, and pixel circuits 920B are provided corresponding to pixels 950R, pixels 950G, and pixels 950B, respectively.

[0077] Figure 7It is a circuit diagram showing the structure of a pixel circuit 920 of a display device 20 manufactured using a transfer device 10 according to an embodiment of the present invention. The pixel circuit 920 is disposed in a region surrounded by a data line 921, a gate line 922, an anode power line 923, and a cathode power line 924. The pixel circuit 920 includes a selection transistor 926, a driving transistor 927, a holding capacitor 928, and an LED element 820. Circuit elements other than the LED element 820 in the pixel circuit 920 are provided on a circuit substrate 900. That is, by mounting the LED element 820 on the circuit substrate 900, the pixel circuit 920 is completed. However, in this specification, there are cases where, for convenience, a circuit structure not including the LED element 820 is described as the pixel circuit 920.

[0078] As Figure 7 shown, the source electrode, gate electrode, and drain electrode of the selection transistor 926 are connected to the data line 921, the gate line 922, and the gate electrode of the driving transistor 927, respectively. The source electrode, gate electrode, and drain electrode of the driving transistor 927 are connected to the anode power line 923, the drain electrode of the selection transistor 926, and the LED element 820, respectively. The holding capacitor 928 is connected between the gate electrode and the drain electrode of the driving transistor 927. That is, the holding capacitor 928 is connected to the drain electrode of the selection transistor 926. The anode and cathode of the LED element 820 are connected to the drain electrode of the driving transistor 927 and the cathode power line 924, respectively.

[0079] For the data line 921, a gradation signal that determines the light emission intensity of the LED element 820 is supplied. For the gate line 922, a gate signal for selecting the selection transistor 926 for writing the gradation signal is supplied. If the selection transistor 926 becomes conductive, the gradation signal is stored in the holding capacitor 928. Then, if the driving transistor 927 becomes conductive, a driving current corresponding to the gradation signal flows through the driving transistor 927. If the driving current output from the driving transistor 927 is input to the LED element 820, the LED element 820 emits light with a light emission intensity corresponding to the gradation signal.

[0080] Referring again to Figure 6 , a data driver circuit 1030 is disposed at a position adjacent in the column direction (D2 direction) with respect to the display area 20a. In addition, a gate driver circuit 1040 is disposed at a position adjacent in the row direction (D1 direction) with respect to the display area 20a. In addition, in Figure 6 , two gate driver circuits 1040 are provided on both sides of the display area 20a, but they may also be provided on only one side.

[0081] Both the data driver circuit 1030 and the gate driver circuit 1040 are arranged in the peripheral area 20b. However, the area where the data driver circuit 1030 is arranged is not limited to the peripheral area 20b. For example, the data driver circuit 1030 can also be arranged on the flexible printed circuit board 1010.

[0082] Figure 7 The shown data line 921 extends from the data driver circuit 1030 in the D2 direction and is connected to the source electrode of the selection transistor 926 in each pixel circuit 920. The gate line 922 extends from the gate driver circuit 1040 in the D1 direction and is connected to the gate electrode of the selection transistor 926 in each pixel circuit 920.

[0083] The terminal portion 1050 is arranged in the terminal area 20c. The terminal portion 1050 is connected to the data driver circuit 1030 via the connection wiring 1051. Similarly, the terminal portion 1050 is connected to the gate driver circuit 1040 via the connection wiring 1052. Further, the terminal portion 1050 is connected to the flexible printed circuit board 1010.

[0084] [3-3. Cross-sectional structure of the display device 20]

[0085] Figure 8 It is a cross-sectional view showing the structure of the pixel 950 of the display device 20 manufactured using the transfer device 10 according to an embodiment of the present invention. The pixel 950 has a driving transistor 927 provided on the support substrate 910.

[0086] The driving transistor 927 includes a semiconductor layer 927a, a gate insulating layer 927b, and a gate electrode 927c. On the semiconductor layer 927a, a source electrode 927e and a drain electrode 927f are connected via an insulating layer 927d. Although not shown, the gate electrode 927c is connected to Figure 7 the drain electrode of the shown selection transistor 926.

[0087] In the same layer as the source electrode 927e and the drain electrode 927f, a wiring 961 is provided. The wiring 961 functions as Figure 7 the anode power supply line 923 shown. Therefore, the source electrode 927e and the wiring 961 are electrically connected by the connection wiring 963 provided on the planarization layer 962. The planarization layer 962 is a transparent resin layer using a resin material such as polyimide or propylene. The connection wiring 963 is a transparent conductive layer using a metal oxide material such as ITO. However, it is not limited to this example, and other metal materials can also be used as the connection wiring 963.

[0088] On the connection wiring 963, an insulating layer 964 made of silicon nitride or the like is provided. On the insulating layer 964, an anode electrode 965 and a cathode electrode 966 are provided. In the present embodiment, the anode electrode 965 and the cathode electrode 966 are transparent conductive layers using a metal oxide material such as ITO. The anode electrode 965 is connected to the drain electrode 927f through an opening provided in the planarization layer 962 and the insulating layer 964.

[0089] The anode electrode 965 and the cathode electrode 966 are respectively connected to the mounting pads 968a and 968b through the planarization layer 967. The mounting pads 968a and 968b are made of a metal material such as tantalum or tungsten, for example. On the mounting pads 968a and 968b, connection electrodes 930a and 930b are respectively provided. The connection electrodes 930a and 930b correspond to Figure 4A the connection electrode 930 shown. That is, electrodes made of tin (Sn) are arranged as the connection electrodes 930a and 930b.

[0090] On the connection electrodes 930a and 930b, the terminal electrodes 830a and 830b of the LED element 820 are respectively joined. As described above, the terminal electrodes 830a and 203b are electrodes made of gold (Au). In addition, as described with reference to Figure 4E there is an alloy layer ( Figure 4E the alloy layer 940 shown) not shown between the connection electrode 930a and the terminal electrode 830a.

[0091] As Figure 7 shown, the terminal electrode 830a of the LED element 820 is connected to the anode electrode 965 connected to the drain electrode 927f of the driving transistor 927. The terminal electrode 830b of the LED element 820 is connected to the cathode electrode 966. The cathode electrode 966 is electrically connected to Figure 7 the cathode power supply line 924 shown.

[0092] In addition, in Figure 8 a flip-chip type LED element 820 is shown, but a face-up type can also be used as the LED element 820.

[0093] The display device 20 manufactured using the transfer device 10 of the present embodiment firmly mounts the LED element 820 by the pushing of the pushing jig 200, and reduces the thermal damage to the LED element 820 or the circuit board 900 by the cooling of the pushing jig 200.

[0094] <Second Embodiment>

[0095] Refer to Figure 9A and Figure 9B, the pressing jig 200A different from the pressing jig 200 of the transfer device 10 will be described. Figure 9A and Figure 9B are a schematic perspective view and a cross-sectional view of the pressing jig 200A according to an embodiment of the present invention. More specifically, Figure 9B is along Figure 9A The cross-sectional view of the pressing jig 200A cut along the line A1 - A2 shown. In addition, hereinafter, when the structure of the pressing jig 200A is the same as that of the pressing jig 200, the description thereof may be omitted.

[0096] As Figure 9A shown, the pressing jig 200A includes a plate-like member 210 and a heat sink 220A. The heat sink 220A is provided in contact with the peripheral portion of the plate-like member 210. In addition, the heat sink 220A includes an inlet hole 221A for supplying liquid and an outlet hole 222A for discharging the liquid. The heat sink 220A is a water-cooled type, while the heat sink 220 is an air-cooled type. That is, in the pressing jig 200A, as Figure 9B shown, a flow path 223A is provided in the heat sink 220A, and the liquid supplied from the inlet hole 221A flows in the flow path 223A and is discharged from the outlet hole 222A.

[0097] In addition, the liquid supplied to the heat sink 220A is, for example, water, but is not limited thereto. The liquid supplied to the heat sink 220A may also be a fluorine-based refrigerant. In addition, a chiller or a pump may be used to circulate the liquid supplied to the heat sink 220A.

[0098] In the pressing jig 200A, the liquid flowing in the heat sink 220A can absorb the heat of the plate-like member 210 in contact with the heat sink 220A. That is, in the present embodiment, by providing a cooling portion (heat sink 220A) on the pressing jig 200A, the heat generated in the photomask 400, the element substrate 800, and the circuit substrate 900 by the irradiation of the laser is conducted to the plate-like member 210, and the heat sink 220A can absorb or dissipate the heat conducted to the plate-like member 210. Therefore, the pressing jig 200A can suppress the temperature rise of the photomask 400, the element substrate 800, and the circuit substrate 900. Thus, if the LED element 820 is transferred from the element substrate 800 to the circuit substrate 900 using the pressing jig 200A, the temperature rise of the photomask 400, the element substrate 800, and the circuit substrate 900 can be suppressed, so that the transfer accuracy of the LED element 820 to a specified position is improved. In addition, the damage caused by the heat to the LED element 820 or the circuit substrate 900 can be reduced.

[0099] <Third Embodiment>

[0100] Refer to Figure 10A andFigure 10B Another pressing jig 200B will be described. Figure 10A And Figure 10B FIGS. and are a schematic perspective view and a cross-sectional view, respectively, of a pressing jig 200B according to an embodiment of the present invention. More specifically, Figure 10B is a cross-sectional view of the pressing jig 200B cut along the line B1 - B2 shown in Figure 10A In addition, hereinafter, when the structure of the pressing jig 200B is the same as that of the pressing jig 200, the description thereof may be omitted.

[0101] As Figure 10A shown, the pressing jig 200B includes a plate-like member 210 and a heat sink 220B. The heat sink 220B is provided in contact with the plate-like member 210 at the peripheral portion of the plate-like member 210. As Figure 10B shown, the heat sink 220B is provided in contact with not only the upper surface and the lower surface but also the side surfaces at the peripheral portion of the plate-like member 210. That is, since the area of contact between the heat sink 220B and the plate-like member 210 is large, the heat conduction from the plate-like member 210 to the heat sink 220B is increased.

[0102] In the present embodiment, by providing a cooling portion (heat sink 220B) in the pressing jig 200B, the heat generated in the photomask 400, the element substrate 800, and the circuit substrate 900 is conducted to the plate-like member 210 by laser irradiation, and the heat sink 220B can absorb or dissipate the heat conducted to the plate-like member 210. Therefore, the pressing jig 200B can suppress the temperature rise of the photomask 400, the element substrate 800, and the circuit substrate 900. Thus, if the LED element 820 is transferred from the element substrate 800 to the circuit substrate 900 using the pressing jig 200B, the temperature rise of the photomask 400, the element substrate 800, and the circuit substrate 900 can be suppressed, so that the transfer accuracy of the LED element 820 to a specified position is improved. In addition, the damage caused by heat to the LED element 820 or the circuit substrate 900 can be reduced.

[0103] <Fourth Embodiment>

[0104] Referring to Figure 11A And Figure 11B Another pressing jig 200C will be described. Figure 11A And Figure 11B FIGS. and are a schematic perspective view and a cross-sectional view, respectively, of a pressing jig 200C according to an embodiment of the present invention. More specifically, Figure 11B is a cross-sectional view of the pressing jig 200C cut along the line C1 - C2 shown in Figure 11A In addition, hereinafter, when the structure of the pressing jig 200C is the same as that of the pressing jig 200, the description thereof may be omitted.

[0105] As shown Figure 11A in FIG. 3, the pressing jig 200C includes a plate-like member 210C. The plate-like member 210C includes an inlet hole 211C for supplying a liquid and an outlet hole 212C for discharging the liquid. That is, in the pressing jig 200C, as shown Figure 11B in FIG. 3, a flow path 213C is provided in the plate-like member 210C, and the liquid supplied from the inlet hole 211C flows in the flow path 213C and is discharged from the outlet hole 212C.

[0106] In the pressing jig 200C, the liquid flowing in the plate-like member 210C can take away the heat of the plate-like member 210C. Therefore, in the present embodiment, by providing a cooling portion inside the plate-like member 210C of the pressing jig 200C, the heat generated in the light-shielding mask 400, the element substrate 800, and the circuit substrate 900 by the irradiation of the laser is conducted to the plate-like member 210, and the heat transferred by the cooling portion inside the plate-like member 210C can be absorbed or dissipated. Therefore, the pressing jig 200C can suppress the temperature rise of the light-shielding mask 400, the element substrate 800, and the circuit substrate 900. Thus, if the LED element 820 is transferred from the element substrate 800 to the circuit substrate 900 using the pressing jig 200C, the temperature rise of the light-shielding mask 400, the element substrate 800, and the circuit substrate 900 can be suppressed, so that the accuracy of the transfer of the LED element 820 to a specified position is improved. In addition, the damage caused by the heat to the LED element 820 or the circuit substrate 900 can be reduced.

[0107] As for the above-described embodiments of the present invention, as long as they are not mutually contradictory, they can be appropriately combined and implemented. A form in which elements are appropriately added, deleted, or designed to be changed, or a form in which processes are added, omitted, or conditions are changed, based on each embodiment, as long as it has the gist of the present invention, is included in the scope of the present invention.

[0108] In addition, even if there are other effects different from the effects brought about by the forms of the above-described embodiments, those that are obvious from the description of this specification or can be easily predicted by those skilled in the art should of course be considered as brought about by the present invention.

Claims

1. A transfer device, characterized in that: It includes: A stage for placing a circuit board provided with a pixel circuit for driving an LED element; A pressing jig for pressing an element board provided with the above-mentioned LED element against the above-mentioned circuit board; and A laser irradiation unit for irradiating the above-mentioned LED element with laser light through the above-mentioned pressing jig and the above-mentioned element board; The above-mentioned pressing jig includes a plate-like member including a transmission region through which the above-mentioned laser passes and a cooling unit for cooling the above-mentioned plate-like member, The above-mentioned cooling unit is provided at a peripheral portion of the above-mentioned transmission region of the above-mentioned plate-like member, The above-mentioned cooling unit has a plurality of protrusions that are in close contact with the above-mentioned plate-like member by pressing.

2. The transfer device according to claim 1, characterized in that: The above-mentioned cooling unit is a heat sink.

3. The transfer device according to claim 1, characterized in that: The above-mentioned cooling unit is water-cooled.

4. The transfer device according to any one of claims 1 to 3, characterized in that: The above-mentioned plate-like member is quartz glass.

5. The transfer device according to claim 1, characterized in that: It further includes a patterned light-shielding mask between the above-mentioned pressing jig and the above-mentioned element board.

6. The transfer device according to claim 1, characterized in that: The above-mentioned laser irradiation unit irradiates two kinds of the above-mentioned lasers with different wavelengths.

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