LED wafer, carrier substrate for LED chip, method for manufacturing display device, and method for repairing display device

Abstract

To provide an LED wafer and a carrier substrate for an LED chip that can be easily mounted on a mounting pad of the LED chip, provide a method for manufacturing a display device using the LED wafer and the carrier substrate for an LED chip that can be easily mounted on the mounting pad of the LED chip, and provide a method for repairing the display device using the carrier substrate for an LED chip that can be easily mounted on the mounting pad from which the LED chip has been removed.SOLUTION: An LED wafer comprises: at least one LED element laminate including a first semiconductor layer of one conductivity type, a light-emitting layer, and a second semiconductor layer of a conductivity type opposite to the one conductivity type, stacked on a crystal substrate; at least one terminal electrode that forms contact with the first semiconductor layer or the second semiconductor layer; and a conductive bonding material layer on the at least one terminal electrode.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an LED (Light Emitting Diode) wafer, a carrier substrate for LED chips, a method for manufacturing a display device, and a method for repairing a display device. [Background technology]

[0002] In recent years, LED displays, in which tiny LEDs (so-called micro LEDs) are mounted in each pixel, have been developed as next-generation display devices. LED displays have a structure in which multiple LED chips are mounted on a circuit board that forms a pixel array. The circuit board has drive circuits for emitting light from the LEDs at positions corresponding to each pixel. These drive circuits are electrically connected to each LED chip.

[0003] When multiple LED chips are mounted on a circuit board, poor connections may occur between each LED and the electrodes provided on the circuit board. Patent Document 1 discloses a method for non-destructively checking whether or not there are poor connections between the LEDs and the circuit board when multiple LED chips are mounted on a circuit board, in order to improve the reliability of a display device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,096,740 Summary of the Invention [Problem to be solved by the invention]

[0005] In display devices with mounted LED chips, the yield is a major issue when mounting the LED chips from the carrier substrate on which they are formed to the circuit board. For example, while conventional technology uses laser light to bond the LED chip to the circuit board, a connection failure between the LED chip and the circuit board can occur. One approach is to remove the LED chip with such a connection failure or to cut and open the wiring on the circuit board, and then remount a new LED chip on a spare mounting pad located near the defective location.

[0006] However, providing spare LED chip mounting pads within the pixels of the circuit board increases the area per pixel, making it difficult to miniaturize the pixels and making it impossible to accommodate higher resolution.

[0007] Another idea is to remove an LED chip that has developed a connection problem from a mounting pad and then reuse the same mounting pad from which the LED chip was removed, without providing a spare mounting pad as described above in the display device. However, it is extremely difficult to accurately target and reposition a bonding material (solder, microbumps, bonding resin, etc.) on the mounting pad from which the LED chip has been removed.

[0008] In view of the above problems, one embodiment of the present invention aims to provide an LED wafer and an LED chip carrier substrate that can be easily mounted on mounting pads for LED chips.Another embodiment of the present invention aims to provide a method for manufacturing a display device using an LED wafer and an LED chip carrier substrate that can be easily mounted on mounting pads for LED chips.Another embodiment of the present invention aims to provide a method for repairing a display device that uses an LED chip carrier substrate that can be easily mounted on mounting pads from which LED chips have been removed. [Means for solving the problem]

[0009] One embodiment of the present invention is an LED wafer, which includes at least one LED element stack including a first semiconductor layer of one conductivity type, a light-emitting layer, and a second semiconductor layer having an opposite conductivity type to the first conductivity type stacked on a crystalline substrate, at least one terminal electrode forming contact with the first semiconductor layer or the second semiconductor layer, and a conductive bonding material layer on the at least one terminal electrode.

[0010] One embodiment of the present invention is a carrier substrate for LED chips, the carrier substrate for LED chips comprising a carrier substrate and at least one LED chip on the carrier substrate, the at least one LED chip including a semiconductor layer including a first semiconductor layer of one conductivity type, a light-emitting layer, and a second semiconductor layer of an opposite conductivity type stacked thereon, at least one terminal electrode forming contact with the first semiconductor layer or the second semiconductor layer, and a conductive bonding material layer on the terminal electrode, the at least one LED chip being disposed on the carrier substrate with the surface provided with the conductive bonding material layer facing up, and the at least one LED chip being fixed to the carrier substrate by an adhesive layer.

[0011] One embodiment of the present invention is a method for manufacturing a display device, which includes aligning an LED chip carrier substrate including a carrier substrate, at least one LED chip on the carrier substrate, a conductive bonding material layer on a first surface of the at least one LED chip, and an adhesive layer on a second surface of the at least one LED chip with a circuit substrate having a pixel area so that the pixel area and the at least one LED chip overlap in a plan view, and mounting the at least one LED chip in the pixel area.

[0012] One embodiment of the present invention is a method for repairing a display device, which includes removing a first LED chip from a circuit board including a pixel region, the first LED chip being disposed at a first location of a first pixel provided in the pixel region and determined to be defective, and mounting the at least one LED chip at the first location on an LED chip carrier substrate including a carrier substrate, at least one LED chip on the carrier substrate, a conductive bonding material layer on a first surface of the at least one LED chip, and an adhesive layer on a second surface of the at least one LED chip, the at least one LED chip being aligned with the first location. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view showing an LED wafer according to one embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a portion of an LED wafer according to one embodiment of the present invention. [Figure 3] 1 is a plan view showing an LED wafer according to one embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing a portion of an LED wafer according to one embodiment of the present invention. [Figure 5] 1 is a plan view showing a carrier substrate of an LED chip according to one embodiment of the present invention. [Figure 6] 1 is a plan view showing a carrier substrate of an LED chip according to one embodiment of the present invention. [Figure 7] 2 is a cross-sectional view showing a portion of a carrier substrate of an LED chip according to one embodiment of the present invention. [Figure 8] 1 is a plan view showing a carrier of an LED chip according to one embodiment of the present invention. [Figure 9] 2 is a cross-sectional view showing a portion of a carrier substrate of an LED chip according to one embodiment of the present invention. [Figure 10] FIG. 1 is a flowchart illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 11]1A to 1C are plan views illustrating a method for manufacturing a display device according to an embodiment of the present invention. [Figure 12] 1A to 1C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 13] 1A to 1C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 14] FIG. 1 is a flowchart illustrating a method for repairing a display device according to an embodiment of the present invention. [Figure 15] 1A to 1C are cross-sectional views illustrating a method for repairing a display device according to an embodiment of the present invention. [Figure 16] 1A to 1C are cross-sectional views illustrating a method for repairing a display device according to an embodiment of the present invention. [Figure 17] 1A to 1C are cross-sectional views illustrating a method for repairing a display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various forms without departing from the spirit of the present invention. The present invention should not be interpreted as being limited to the description of the embodiments exemplified below. In order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part more schematically than the actual form. However, the drawings are merely examples and do not limit the interpretation of the present invention.

[0015] When describing embodiments of the present invention, the direction from the substrate toward the LED chip is referred to as "upper," and the opposite direction is referred to as "lower." However, the terms "upper" and "lower" merely describe the upper-level relationship of each element. For example, the term "LED chip is disposed on a substrate" also includes cases where other components are interposed between the substrate and the LED chip. Furthermore, the terms "upper" and "lower" include not only cases where elements overlap in a plan view, but also cases where they do not overlap.

[0016] When describing embodiments of the present invention, elements having the same functions as elements already described may be designated by the same reference numerals or the same reference numerals with alphabetic characters or other symbols, and description thereof may be omitted.

[0017] First Embodiment In this embodiment, an LED wafer 10, which is one embodiment of the present invention, will be described with reference to FIGS.

[0018] 1 is a plan view showing an LED wafer 10 according to one embodiment of the present invention. The LED wafer 10 includes a crystalline substrate 100, an LED element stack 106, terminal electrodes 108, and a conductive bonding material layer 110.

[0019] The crystal substrate 100 is provided with a region 102 in which an LED element stack 106 is arranged, and a peripheral region 104 surrounding the periphery of the region 102. The multiple LED element stacks 106 are arranged in a matrix in a first direction D1 (row direction) and a second direction (column direction) shown in Fig. 1. The peripheral region 104 can be provided with markers or the like to be used when transferring the LED element stack 106 to another substrate.

[0020] The LED element stack 106 is provided with a terminal electrode 108 and a conductive bonding material layer 110. The terminal electrode 108 can be provided within the LED element stack 106, as shown in FIG. 1. The shape of the terminal electrode 108 can be matched to the shape of the LED element stack 106 in a planar view. The conductive bonding material layer 110 can be provided within the terminal electrode 108, as shown in FIG. 1. The shape of the conductive bonding material layer 110 can be matched to the shape of the terminal electrode 108 in a planar view.

[0021] Although FIG. 1 shows an example in which the LED element stack 106, the terminal electrode 108, and the conductive bonding material layer 110 are each rectangular in shape, they are not limited to rectangular shapes and can be formed into any shape.

[0022] 2 is a cross-sectional view showing a portion of an LED wafer according to one embodiment of the present invention, specifically, an enlarged cross-sectional view taken along line A1-A2 shown in FIG.

[0023] As shown in Fig. 2, an LED element stack 106 is provided on a crystal substrate 100. At least one terminal electrode 108 may be provided on the LED element stack 106. A conductive bonding material layer 110 is provided on the terminal electrode 108. The conductive bonding material layer 110 may be disposed so as to sandwich the crystal substrate 100 and the LED element stack 106 therebetween.

[0024] The crystal substrate 100 can support each layer provided on the crystal substrate 100. Furthermore, the crystal substrate 100 is preferably a substrate on which the first semiconductor layer 106N, the second semiconductor layer 106P, and the light-emitting layer 106E included in the LED element stack 106 can grow as crystals. The crystal substrate 100 can be, for example, a sapphire substrate, a gallium nitride substrate, or a silicon carbide substrate.

[0025] The LED element stack 106 includes a first semiconductor layer 106N of one conductivity type, a light-emitting layer 106E, and a second semiconductor layer 106P of the opposite conductivity type, which are stacked on a crystal substrate 100. The first semiconductor layer 106N is disposed on the crystal substrate 100. The light-emitting layer 106E is disposed on the first semiconductor layer 106N. The second semiconductor layer 106P is disposed on the light-emitting layer 106E. As shown in FIGS. 1 and 2, the multiple LED element stacks 106 can be separated from one another by separation grooves 112. The separation grooves 112 can be formed by processing such as etching.

[0026] The first semiconductor layer 106N is, for example, a layer formed of an n-type semiconductor, and the second semiconductor layer 106P is, for example, a layer formed of a p-type semiconductor. The n-type semiconductor layer 106N and the p-type semiconductor layer 106P can be made of, for example, gallium nitride. The light-emitting layer 106E can be made of, for example, a material containing indium, gallium, and nitrogen, and may have a quantum well structure. The emission color of the light-emitting layer 106E can be changed by adjusting the composition ratio of indium and gallium.

[0027] The terminal electrode 108 forms a contact with the second semiconductor layer 106P. The terminal electrode 108 can be directly or electrically connected to the second semiconductor layer 106P. The terminal electrode 108 can be made of a conductive material such as gold (Au), copper (Cu), silver (Ag), tin (Sn), or aluminum (Al).

[0028] The conductive bonding material layer 110 is a conductive layer for connecting the LED element stack 106 to the circuit board 30, which will be described later, and is provided on the LED element stack 106. The conductive bonding material layer 110 can be made of a conductive material such as silver paste, solder (Sn), a paste containing metal nanoparticles, or an anisotropic conductive film (ACF).

[0029] In the embodiment of the present invention described above, a first semiconductor layer 106N of one conductivity type, a light-emitting layer 106E, and a second semiconductor layer 106P having a conductivity type opposite to the one conductivity type are stacked on a crystal substrate 100, and the terminal electrode 108 forms contact with the second semiconductor layer 106P, resulting in a so-called vertically structured LED element stack 106. However, the connection between the LED element stack and the terminal electrode 108 is not limited to the vertically structured connection.

[0030] Fig. 3 is a plan view showing an LED wafer according to one embodiment of the present invention. As shown in Fig. 3, this embodiment shows an LED element stack 106 with a flip-type structure having two terminal electrodes 108N and 108P in plan view. In Figs. 3 and 4, the same components as those in the LED element stack 106 shown in Figs. 1 and 2 are designated by the same reference numerals, and redundant descriptions will be omitted.

[0031] The LED element stack 106F has, in a plan view, a region 106Ns where the first semiconductor layer 106N is exposed and a region 106PS where the second semiconductor layer 106P is exposed, and may include a first terminal electrode 108N and a second terminal electrode 108P. As shown in FIG. 3 , the region 106NS where the first semiconductor layer 106N is exposed may be adjacent to the region 106PS where the second semiconductor layer 106P is exposed. The region 106NS where the first semiconductor layer 106N is exposed may be disposed so as to surround the first terminal electrode 108N. The region 106PS where the second semiconductor layer 106P is exposed may be disposed so as to surround the second terminal electrode 108P. The region 106NS where the first semiconductor layer 106N is exposed and the region 106PS where the second semiconductor layer 106P is exposed may be disposed so as to partially surround the first terminal electrode 108N and the second terminal electrode 108P, rather than entirely surrounding each other.

[0032] 4 is a cross-sectional view showing a portion of an LED wafer according to one embodiment of the present invention, specifically an enlarged cross-sectional view taken along line B1-B2 shown in FIG.

[0033] The first terminal electrode 108N can form a contact with the first semiconductor layer 106N. The first terminal electrode 108N can be directly or electrically connected to the first semiconductor layer 106N. The second terminal electrode 108P can form a contact with the second semiconductor layer 106P. The second terminal electrode 108P can be directly or electrically connected to the second semiconductor layer 106P. A conductive bonding material layer 110 can be disposed on the upper surface of the first terminal electrode 108 and the second terminal electrode 108P. As shown in FIG. 4, a first conductive bonding material layer 110-1 can be disposed on the upper surface of the first terminal electrode 108N. A second conductive bonding material layer 110-2 can be disposed on the upper surface of the second terminal electrode 108P.

[0034] As described above, in the LED wafer 10 according to one embodiment of the present invention, the conductive bonding material layer 110 is provided on the terminal electrodes 108 on the LED element stack 106, and therefore the LED element stack 106 can be mounted on the LED chip mounting pad on the circuit board 30 without providing the conductive bonding material layer 110 on the LED chip mounting pad.

[0035] In the embodiment of the present invention described above, the crystalline substrate 100 is used as the substrate supporting the LED element stack 106. However, the substrate supporting the LED element stack 106 is not limited to the crystalline substrate 100.

[0036] Second Embodiment In this embodiment, a carrier substrate 20 for an LED chip, which is one embodiment of the present invention, will be described with reference to FIGS.

[0037] FIG. 5 is a plan view showing an LED chip carrier substrate according to one embodiment of the present invention. As shown in FIG. 5, in this embodiment, a carrier substrate 200A is used as a substrate supporting an LED chip 1206. The LED chip carrier substrate 20A shown in FIG. 5 is a carrier substrate obtained by transferring the LED chip from the LED wafer 10 between substrates at least twice. That is, the LED chip carrier substrate shown in FIG. 5 shows a state in which the LED chip is transferred from the LED wafer 10 to a primary transfer substrate, and then the LED chip is transferred again from the primary transfer substrate to the carrier substrate 200A. The LED chip 1206 is obtained by singulating the LED wafer 10 shown in the first embodiment. The LED chip carrier substrate 20 includes the carrier substrate 200A, the LED chip 1206, and an adhesive layer 214.

[0038] The carrier substrate 200A is provided with an area 202 in which the LED chips 1206 are arranged and a peripheral area 204 surrounding the area 202. A plurality of LED chips 1206 can be provided in the area 202. The plurality of LED chips 1206 are arranged on the carrier substrate 200A at a distance from one another. The plurality of LED chips 1206 are arranged in a matrix in a first direction D1 (row direction) and a second direction (column direction) shown in FIG. 5. The peripheral area 204 can be provided with markers or the like to be used when transferring the LED chips 1206 to another carrier substrate.

[0039] An adhesive layer 214 is provided on the carrier substrate 200A. The adhesive layer 214 can be arranged to cover the carrier substrate 200A. The adhesive layer 214 may be arranged to cover the region 202 where the LED chip 1206 is to be disposed. In FIG. 5 , the adhesive layer 214 is shown as a continuous layer in the region 202 where the LED chip 1206 is to be disposed, but it may be separated. For example, the adhesive layer 214 may be provided in the region overlapping the LED chip 1206, and may be separated from the adhesive layer 214 provided in the region overlapping the adjacent LED chip 1206.

[0040] The spacing between the LED chips 1206 on the carrier substrate 200A can be adjusted. The spacing S1 between the LED chips 1206 on the carrier substrate 200A can be the same as or wider than the spacing between the LED element stacks 106 on the crystal substrate 100 described above. By transferring the LED chips 1206 between carrier substrates, the spacing S1 between the LED chips 1206 can be further widened. For example, as shown in FIGS. 5 and 6 , if the spacing between the LED chips 1206 on the carrier substrate 200A is S1, the spacing S2 between the LED chips 1206 can be adjusted to be wider than S1 by thinning out the LED chips 1206 on the carrier substrate 200A and transferring them to another carrier substrate, and then transferring them from the other carrier substrate to the carrier substrate 200B. In this case, the spacing S1 can be adjusted by, for example, transferring the LED chips on carrier substrate 200A to an adhesive layer on another carrier substrate that is more adhesive than adhesive layer 214A, and then transferring the transferred LED chips on the other carrier substrate to adhesive layer 214B on carrier substrate 200B that is more adhesive than the adhesive layer 214A. By thinning out the LED chips by column or row during transfer, the spacing S1 can be adjusted to a spacing S2 of, for example, 50 μm to 100 μm. Also, for example, as shown in FIG. 6, the spacing S1 between the LED chips 1206 can be adjusted to a distance (spacing S2) corresponding to an area 206×2 where two LED chips can be mounted.

[0041] 7 is an enlarged cross-sectional view of a portion of a carrier substrate of an LED chip according to one embodiment of the present invention, taken along line C1-C2 in FIG.

[0042] 7, an LED chip 1206 and an adhesive layer 214A are provided on a carrier substrate 200A. The adhesive layer 214A is disposed on the carrier substrate 200A. The LED chip 1206 is disposed on the adhesive layer 214A.

[0043] The carrier substrate 200A can support each layer provided thereon. The carrier substrate 200A can be, for example, a light-transmitting substrate such as a glass substrate, a quartz substrate, or a resin substrate. The resin substrate can be, for example, a flexible substrate such as a polyimide substrate, an acrylic substrate, a siloxane substrate, or a fluororesin substrate. When the LED chip 1206 is transferred to the circuit board using laser light, the carrier substrate 200A is preferably a light-transmitting substrate that transmits laser light.

[0044] The adhesive layer 214A fixes the LED chip 1206 to the carrier substrate 200A. The adhesive layer 214A is disposed between the carrier substrate 200A and the LED chip 1206. The adhesive layer 214A can be made of a material that can adhere and detach the LED chip 1206. Examples of the adhesive and detachable material that can be used include a silicon-based adhesive and a polyimide-based adhesive. Examples of the silicon-based adhesive include polydimethylsiloxane (PDMS). Examples of the polyimide-based adhesive include polyimide (PI).

[0045] The LED chip 1206 includes a semiconductor layer 206, a terminal electrode 208, and a conductive bonding material layer 210 on the terminal electrode 208. The LED chip 1206 is disposed on the carrier substrate 200A with the surface on which the conductive bonding material layer 210 is provided as an upper surface 1206S-1 and the surface on which the adhesive layer 214 is provided as a lower surface 1206S-2. A plurality of LED chips 1206 are provided on the carrier substrate 200A, and the plurality of LED chips 1206 can be disposed on the carrier substrate 200A at a distance from each other.

[0046] The semiconductor layer 206 is a layer in which a first semiconductor layer 206N of one conductivity type, a light-emitting layer, and a second semiconductor layer having the opposite conductivity type to the first conductivity type are stacked. The semiconductor layer 206 can be disposed on an adhesive layer 214A. The first semiconductor layer 106N, the light-emitting layer 106E, and the second semiconductor layer 106P can be the same as those in the LED element stack 106 described above.

[0047] The terminal electrode 208 forms contact with the first semiconductor layer 206N or the second semiconductor layer 206P. The terminal electrode 208 can be directly or electrically connected to the first semiconductor layer 106N or the second semiconductor layer 106P. The terminal electrode 208 can be disposed on the semiconductor layer 206. The terminal electrode 208 can be the same as the terminal electrode 108 used in the LED wafer 10 described above.

[0048] The conductive bonding material layer 210 can be disposed on the terminal electrode 208. The conductive bonding material layer 110 can be the same as the conductive bonding material layer 110 used in the LED wafer 10 described above.

[0049] In the embodiment of the present invention described above, a first semiconductor layer 206N of one conductivity type, a light emitting layer 206E, and a second semiconductor layer 206P having a conductivity type opposite to the one conductivity type are stacked on a carrier substrate 200A, and the terminal electrode 208 forms contact with the first semiconductor layer 206N or the second semiconductor layer 206P, resulting in a so-called vertically structured LED chip 1206. However, the connection between the LED chip 1206 and the terminal electrode 208 is not limited to the vertically structured connection.

[0050] Fig. 8 is a plan view showing the carrier substrate 20 of an LED chip according to one embodiment of the present invention. As shown in Fig. 8, this embodiment is an LED chip 1206 with a flip-type structure having two terminal electrodes 108N and 108P in plan view. In Figs. 8 and 9, the same components as those of the LED chip 1206 shown in Figs. 6 and 7 are designated by the same reference numerals, and redundant descriptions will be omitted.

[0051] The LED chip 1206F has, in a plan view, a region 206NS where the first semiconductor layer 206N is exposed and a region 206PS where the second semiconductor layer 206P is exposed, and may include a first terminal electrode 208N and a second terminal electrode 208P. As shown in FIG. 8 , the region 206NS where the first semiconductor layer 206N is exposed may be adjacent to the region 206PS where the second semiconductor layer 206P is exposed. The region 206NS where the first semiconductor layer 206N is exposed may be arranged to surround the first terminal electrode 208N. The region 206PS where the second semiconductor layer 206P is exposed may be arranged to surround the second terminal electrode 208P. The region 206NS where the first semiconductor layer 206N is exposed and the region 206PS where the second semiconductor layer 206P is exposed may be arranged to partially surround the first terminal electrode 208N and the second terminal electrode 208P, rather than entirely.

[0052] 9 is a cross-sectional view showing a portion of an LED wafer according to one embodiment of the present invention, specifically an enlarged cross-sectional view taken along line E1-E2 shown in FIG.

[0053] The first terminal electrode 208N can form a contact with the first semiconductor layer 206N. The first terminal electrode 208N can be directly or electrically connected to the first semiconductor layer 206N. The second terminal electrode 208P can form a contact with the second semiconductor layer 206P. The second terminal electrode 208P can be directly or electrically connected to the second semiconductor layer 206P. A conductive bonding material layer 210 can be disposed on the upper surface of the first terminal electrode 208N and the second terminal electrode 208P. As shown in FIG. 9 , a first conductive bonding material layer 210-1 can be disposed on the upper surface of the first terminal electrode 208N. A second conductive bonding material layer 210-2 can be disposed on the upper surface of the second terminal electrode 208P.

[0054] As described above, by providing a conductive bonding material layer 210 on the terminal electrode 208 of the LED chip carrier substrate 20, the LED chip 1206 can be mounted on the LED chip mounting pad on the circuit board 30 without providing a conductive bonding material layer 210 on the LED chip mounting pad.

[0055] Third Embodiment In this embodiment, a method for manufacturing a display device, which is one embodiment of the present invention, will be described with reference to Fig. 10 to Fig. 13. Descriptions of configurations that are the same as or similar to those described in the first or second embodiment may be omitted.

[0056] (Display Device Manufacturing Method) Fig. 10 is a flowchart showing a method for manufacturing a display device according to one embodiment of the present invention. Specifically, Fig. 10 shows a process for mounting a plurality of LED chips 1206 on a circuit board. Fig. 11 is a plan view showing a method for manufacturing a display device according to one embodiment of the present invention. Figs. 12 and 13 are cross-sectional views showing a method for manufacturing a display device according to one embodiment of the present invention. Figs. 11 and 12 show a simplified configuration of the LED chip 1206 shown in Fig. 7.

[0057] (Circuit board manufacturing process) First, in step S10 of Fig. 10, drive circuits 318 for causing LEDs to emit light using thin film transistors (TFTs) are fabricated at positions corresponding to each pixel. These drive circuits 318 are electrically connected to each LED chip 1206. Next, in step S11 of Fig. 10, mounting pads are fabricated to electrically connect the drive circuits 318 fabricated at positions corresponding to each pixel to the LED chip 1206.

[0058] (LED chip carrier substrate manufacturing process) 10, an LED element stack 106 is fabricated on the LED wafer 10, and terminal electrodes 108 are formed on the LED element stack 106. Next, in step S21 of Fig. 10, the LED element stack 106 is transferred from the LED wafer 10 to the carrier substrate 200A to fabricate the LED chip 1206. Furthermore, in step S22 of Fig. 10, a conductive bonding material layer 110 is formed on the LED chip 1206 on the carrier substrate 204A.

[0059] (LED chip mounting process) 10, the carrier substrate 200A is placed opposite the circuit substrate 30, and the circuit substrate 30 and the LED chip carrier substrate 20 are aligned. Specifically, as shown in Fig. 11, the circuit substrate 30 and the LED chip carrier substrate 20 are aligned so that the mounting pads 316 provided in each pixel of the pixel region 302 of the circuit substrate 30 overlap with at least one LED chip 1206 arranged in the region 202 of the carrier substrate 200 in a plan view.

[0060] In cross-sectional view, for example, as shown in FIG. 12, the circuit board 30 and the carrier substrate 20 of the LED chip are aligned so that the mounting pads 316 provided in each pixel of the pixel region 302 of the circuit board 30 and the LED chip 1206 overlap each other.

[0061] Next, in step S31 of Fig. 10, the LED chip 1206 is peeled off from the carrier substrate 200A. The LED chip 1206 is peeled off. A known method for peeling off an LED chip may be used. For example, as shown in Fig. 12, a laser beam (arrow) is irradiated onto the adhesive layer 214A or the LED chip 1206 to peel off the LED chip 1206 from the carrier substrate 200A. At this time, the peeled LED chip 1206 is transferred onto the mounting pad 316 of each pixel.

[0062] Alternatively, for example, the carrier substrate 20 of the LED chip is pressed against the circuit board 30, and the conductive bonding material layer 210 of the LED chip 1206 is brought into close contact with the mounting pad 316 of the circuit board 30. Then, for example, the conductive bonding material layer 210 or the mounting pad 316 is heated by laser irradiation or the like, to fuse the conductive bonding material layer 210 and the mounting pad 316 together. Finally, as shown in FIG. 13 , the carrier substrate 200 is lifted up, and the LED chip 1206 is peeled off from the carrier substrate 200. Here, before lifting up the carrier substrate 200, the adhesive layer 214 may be peeled off from the LED chip 1206 or the carrier substrate 200, to separate the LED chip 1206 and the carrier substrate 200.

[0063] 10, the LED chip 1206 is fused to the mounting pad 316. For example, the LED chip 1206 may be fused to the mounting pad 316 by heating the area where the conductive bonding material layer 210 and the mounting pad 316 contact each other using laser irradiation or the like to melt at least a portion of the conductive bonding material layer 210, which is then hardened, thereby fusing the LED chip 1206 to the mounting pad 316 corresponding to each pixel of the circuit board 30.

[0064] By carrying out the steps of fabricating a circuit board, fabricating a carrier substrate for an LED chip, and mounting the LED chip on the circuit board, a display device can be manufactured in which the conductive bonding material layer 210 is in contact with the mounting pad 316 of the circuit board 30.

[0065] In addition, the process of manufacturing the circuit board, the process of manufacturing the carrier substrate for the LED chip, and the process of mounting the LED chip on the circuit board may be carried out as a single unit, or a separately manufactured carrier substrate for the LED chip may be provided for the circuit board manufactured by the above-mentioned process, and the mounting process may be carried out.

[0066] As described above, in the manufacturing method of the display device, when the LED chip 1206 is mounted on the circuit board 30 using the LED chip carrier substrate 20 including the conductive bonding material layer 210 on the upper surface 1206S-1 of at least one LED chip 1206 and the adhesive layer 214 on the lower surface 1206S-2 of at least one LED chip 1206, the LED chip 1206 can be mounted on the circuit board 30 without providing the conductive bonding material layer 210 on the mounting pad 316 of the circuit board 30.

[0067] <Fourth embodiment> In this embodiment, a method for repairing a display device, which is one embodiment of the present invention, will be described with reference to Figures 14 to 17. Descriptions of configurations that are the same as or similar to those described in the first to third embodiments may be omitted.

[0068] (Display Device Repair Method) Fig. 14 is a flowchart showing a method for repairing a display device according to one embodiment of the present invention. Specifically, Fig. 14 shows a process for removing an LED chip 1206D determined to be defective from the circuit board 30 and mounting an LED chip 1206 from an LED chip carrier substrate 200A in the removed location. Figs. 15 to 17 are cross-sectional views showing a method for repairing a display device according to one embodiment of the present invention. Figs. 15 to 17 show a simplified configuration of the LED chip 1206 shown in Fig. 7. It is assumed that an LED chip 1206 is mounted on each pixel of the circuit board 30.

[0069] First, in step S41 of Fig. 14, the LED chip 1206D determined to be defective is removed from the circuit board 30. For example, of the multiple LED chips 1206 provided in the pixel region 302 of the circuit board 30 shown in Fig. 14, the LED chip 1206D determined to be defective is irradiated with laser light (arrow) and removed from the circuit board 30. After removing the LED chip 1206D determined to be defective, a process may be performed to further expose the mounting pad 316 provided in the location from which the LED chip 1206D was removed. As a method for exposing the mounting pad 316, for example, a method of irradiating the mounting pad 316 with laser light can be used.

[0070] 14, the portion from which the LED chip 1206D has been removed is aligned with the LED chip 1206 on the carrier substrate 200A. Specifically, the conductive bonding material layer 110 of the LED chip 1206 on the carrier substrate 200A is aligned with the mounting pad 316 from which the LED chip 1206D has been removed.

[0071] 14, the LED chip 1206 on the carrier substrate 200A is mounted in the location where the LED chip 1206D has been removed. The LED chip 1206 can be mounted on the circuit board 30 in the same manner as in steps S30 to S32 in FIG.

[0072] 6, the carrier substrate 200A can be a carrier substrate 200B in which the spacing S2 between the LED chips 1206 is wide. By using the carrier substrate 200B in which the spacing S2 between the LED chips 1206 is wide, a new LED chip can be mounted on the circuit board 30 without interfering with the LED chips 1206 other than the repaired portion.

[0073] As described above, in the display device repair method, by using the LED chip carrier substrate 20 including the conductive bonding material layer 110 on the upper surface 1206S-1 of at least one LED chip 1206 and the adhesive layer 214 on the lower surface 1206S-2 of at least one LED chip 1206, a new LED chip can be easily placed on the mounting pad from which the defective LED chip was removed. In this case, since the conductive bonding material layer 210 is provided on the LED chip 1206 on the carrier substrate 200A side, there is no need to provide a conductive material for bonding on the circuit board 30 side, and irregularly occurring defective locations can be easily replaced with good LED chips.

[0074] Furthermore, by reusing the mounting pads from which the LED chips have been removed, it becomes unnecessary to provide spare LED chip mounting pads within the pixels provided on the circuit board 30, and this allows for miniaturization of the pixels.

[0075] The above-described embodiments of the present invention can be combined as appropriate as long as they are not mutually inconsistent. Furthermore, even if a person skilled in the art appropriately adds or deletes components or modifies the design based on the display device of each embodiment, or adds or omits processes or modifies conditions, such combinations are included in the scope of the present invention as long as they include the gist of the present invention.

[0076] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0077] 10: wafer, 20: carrier substrate for LED chip, 30: circuit substrate, 100: crystal substrate, 102: region, 104: peripheral region, 106: LED element stack, 106E: light-emitting layer, 106F: LED element stack, 106N: n-type semiconductor layer, 106N: first semiconductor layer, 106Ns: region, 106NS: region, 106P: p-type semiconductor layer, 106P: second semiconductor layer, 106PS: region, 108: terminal electrode, 108N: first terminal electrode, 108P: second terminal electrode, 110: conductive bonding material layer, 110-1: first conductive bonding material layer, 110-2: second conductive bonding material layer, 112: separation groove, 200: carrier substrate, 200A: carrier substrate, 200B: Carrier substrate, 202: region, 204: peripheral region, 206×2: region, 206: semiconductor layer, 206E: light-emitting layer, 206N: first semiconductor layer, 206NS: region, 206P: second semiconductor layer, 206PS: region, 208: terminal electrode, 208N: first terminal electrode, 208P: second terminal electrode, 210: conductive bonding material layer, 210-1: first conductive bonding material layer, 210-2: second conductive bonding material layer, 214: adhesive layer, 214A: adhesive layer, 214B: adhesive layer, 302: pixel region, 316: mounting pad, 318: drive circuit, 1206: LED chip, 1206D: LED chip, 1206F: LED chip, 1206S-1: upper surface, 1206S-2: lower surface

Claims

1. At least one LED element stack including a first semiconductor layer of one conductivity type, a light emitting layer, and a second semiconductor layer having a conductivity type opposite to the first conductivity type stacked on a crystal substrate; at least one terminal electrode that forms contact with the first semiconductor layer or the second semiconductor layer; a conductive bonding material layer on the at least one terminal electrode; LED wafer.

2. The crystal substrate is a sapphire substrate or a gallium nitride substrate. The LED wafer of claim 1 .

3. the at least one LED element stack comprises a plurality of LED element stacks; The plurality of LED element stacks are separated from each other by separation grooves. The LED wafer of claim 1 .

4. the LED element stack has, in a plan view, a region where the first semiconductor layer is exposed and a region where the second semiconductor layer is exposed; the at least one terminal electrode includes a first terminal electrode and a second terminal electrode; the first terminal electrode forms a contact with the first semiconductor layer, and the second terminal electrode forms a contact with the second semiconductor layer; the conductive bonding material layer is disposed on the upper surface of the first terminal electrode and the upper surface of the second terminal electrode, respectively; The LED wafer of claim 1 .

5. a carrier substrate; at least one LED chip on the carrier substrate; an adhesive layer between the carrier substrate and the at least one LED chip; The at least one LED chip a semiconductor layer in which a first semiconductor layer of one conductivity type, a light emitting layer, and a second semiconductor layer having a conductivity type opposite to the first conductivity type are stacked; at least one terminal electrode that forms contact with the first semiconductor layer or the second semiconductor layer; a conductive bonding material layer on the terminal electrode, the at least one LED chip is disposed on the carrier substrate with the surface on which the conductive bonding material layer is provided facing upward; the at least one LED chip is fixed to the carrier substrate by the adhesive layer; Carrier substrate for LED chips.

6. the at least one LED chip comprises a plurality of LED chips; The plurality of LED chips are spaced apart from one another and disposed on the carrier substrate. A carrier substrate for the LED chip according to claim 5.

7. the LED element stack has, in a plan view, a region where the first semiconductor layer is exposed and a region where the second semiconductor layer is exposed; the at least one terminal electrode includes a first terminal electrode and a second terminal electrode; the first terminal electrode forms a contact with the first semiconductor layer, and the second terminal electrode forms a contact with the second semiconductor layer; the conductive bonding material layer is disposed on the upper surface of the first terminal electrode and the upper surface of the second terminal electrode, respectively; A carrier substrate for the LED chip according to claim 5.

8. a carrier substrate for the LED chip, the carrier substrate including a carrier substrate, at least one LED chip on the carrier substrate, a conductive bonding material layer on a first surface of the at least one LED chip, and an adhesive layer on a second surface of the at least one LED chip, and a circuit board having mounting pads corresponding to pixels in a pixel region are arranged to face each other, and are aligned so that the mounting pads and the conductive bonding material layer overlap in a plan view; Peeling the LED chip from the carrier substrate; At least a portion of the conductive bonding material layer is melted and hardened. and fusing the at least one LED chip to the mounting pad. A method for manufacturing a display device.

9. a circuit board including a plurality of LED chips in a pixel region, the circuit board being arranged on a mounting pad at a first location of a first pixel provided in the pixel region, and a first LED chip determined to be defective from among the plurality of LED chips being removed; a carrier substrate for an LED chip, the carrier substrate including: a carrier substrate; at least one LED chip on the carrier substrate; a conductive bonding material layer on a first surface of the at least one LED chip; and an adhesive layer on a second surface of the at least one LED chip, the conductive bonding material layer and the mounting pad being aligned so as to overlap each other; peeling the at least one LED chip from the carrier substrate; melting and curing at least a portion of the conductive bonding material layer to fuse the at least one LED chip to the mounting pad; A method for repairing a display device.

10. removing the first LED chip and then exposing a mounting pad provided at the first location; The method for repairing a display device according to claim 9.

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