Display device manufacturing method

Abstract

To provide a manufacturing method of a display device and a holding substrate, capable of increasing the number of light-emitting devices obtained from one holding substrate.SOLUTION: A manufacturing method of a display device includes the steps of: acquiring a first reference position on a surface of a holding substrate on the basis of positions of a plurality of first alignment marks of the holding substrate; and performing positioning of the holding substrate and a moved substrate so as to match the first reference position and a second reference position on the surface of the moved substrate. The holding substrate is divided into a first partition and a plurality of second partitions in view of one direction. The second partition is arranged with a predetermined interval viewed in one direction. The first partition is provided at one part of a gap between the plurality of second partitions viewed in one direction. The first partition has permeability of a light higher than that of the second partition, and forms the first alignment mark which transmits the light.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a manufacturing method for a display device and a holding substrate. [Background technology]

[0002] There are display devices that combine light-emitting elements such as red, green, and blue to form pixels. The light-emitting elements that make up the pixels are transferred from a holding substrate that holds the light-emitting elements to a substrate to be transferred of the display device. In the manufacturing process of the display device, a technique is sometimes used in which the holding substrate that holds the light-emitting elements is directly pressed against the substrate to be transferred, so that multiple light-emitting elements are transferred at the same time.

[0003] When a holding substrate that holds light-emitting elements is pressed directly against a transferred substrate to transfer the light-emitting elements, the positions of the holding substrate and the transferred substrate are aligned by aligning an alignment mark on the holding substrate with an alignment mark on the transferred substrate.

[0004] Patent Document 1 discloses that an alignment mark for aligning an anisotropic conductive film with a circuit board is formed on an anisotropic conductive film in which conductive particles are dispersed by agglomerating the conductive particles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-4988 Summary of the Invention [Problem to be solved by the invention]

[0006] The alignment marks on the holding substrate were provided in a region that did not hold light-emitting elements, which was formed in a part of the region of the holding substrate that should hold light-emitting elements. As a result, the number of light-emitting elements that could be obtained from one holding substrate was reduced by the area with the alignment marks. Furthermore, in the manufacturing process of the display device, after the light-emitting elements were transferred en bloc from the holding substrate to the transferred substrate, a process of transferring the light-emitting elements to the region of the transferred substrate that corresponds to the region with the alignment marks on the holding substrate was required.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a manufacturing method for a display device and a holding substrate that can increase the number of light-emitting elements that can be obtained from one holding substrate. [Means for solving the problem]

[0008] To achieve the above-mentioned object, a manufacturing method for a display device according to the present disclosure includes a step of acquiring a first reference position on a surface of a holding substrate based on positions of a plurality of first alignment marks on the holding substrate, and a step of aligning the holding substrate and the transferred substrate so that the first reference position is aligned with a second reference position on the surface of the transferred substrate, wherein the holding substrate is partitioned into a plurality of first sections and a plurality of second sections when viewed from one direction, the second sections are arranged at a predetermined interval when viewed from the one direction, the first sections are provided in part of the gaps between the plurality of second sections when viewed from the one direction, and the first sections have a higher light transmittance than the second sections, forming the first alignment mark through which light passes when viewed from the one direction.

[0009] In order to achieve the above-mentioned object, the holding substrate of the present disclosure is partitioned into a plurality of first sections and a plurality of second sections when viewed from one direction, the second sections are arranged at a predetermined interval when viewed from the one direction, the first sections are provided in some of the gaps between the plurality of second sections when viewed from the one direction, the first sections have a higher light transmittance than the second sections, and form an alignment mark through which light passes when viewed from the one direction. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a conceptual bottom view of a holding substrate according to the present embodiment. [Diagram 2] FIG. 2 is a detailed view of the main part of FIG. [Figure 3A] FIG. 3A is a cross-sectional view taken along line AA of FIG. [Figure 3B] FIG. 3B is a cross-sectional view showing a modification of FIG. 3A. [Figure 4] FIG. 4 is a conceptual plan view of a substrate to be transferred. [Figure 5A] FIG. 5A is a conceptual diagram showing a step of obtaining a first reference position in a manufacturing method of a display device. [Figure 5B] FIG. 5B is a conceptual diagram showing a step of obtaining a second reference position in the manufacturing method of the display device. [Figure 5C] FIG. 5C is a conceptual diagram showing an alignment step in the manufacturing method of the display device. [Figure 5D] FIG. 5D is a conceptual diagram showing a step of pressing a holding substrate against a transferred substrate in the manufacturing method of a display device. [Figure 6] FIG. 6 is a conceptual plan view of a holding substrate in accordance with a manufacturing method of a display device. [Figure 7] FIG. 7 is a conceptual plan view of a substrate to be transferred in the manufacturing method of a display device. [Figure 8] FIG. 8 is a conceptual plan view showing a state in which a holding substrate and a transferred substrate are aligned in accordance with the manufacturing method of the display device. [Figure 9] FIG. 9 is a detailed view of a main part of a holding substrate according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The form (embodiment) for carrying out the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited by the contents described in the following embodiments. The components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the components described below can be appropriately combined. Note that the disclosure is merely an example, and those that a person skilled in the art can easily imagine appropriate modifications while maintaining the gist of the disclosure are naturally included in the scope of the present disclosure. In addition, in order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment, but they are merely examples and do not limit the interpretation of the present disclosure. In addition, in this specification and each figure, elements similar to those described above with respect to the previously mentioned figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0012] An embodiment for carrying out the present disclosure will be described below with reference to Figs. 1 to 4. Fig. 1 is a conceptual bottom view of a holding substrate according to this embodiment. Fig. 2 is a detailed view of a main part of Fig. 1. Fig. 3A is a cross-sectional view taken along line AA in Fig. 2. Fig. 3B is a cross-sectional view showing a modified example of Fig. 3A. Fig. 4 is a conceptual plan view of a substrate to be transferred.

[0013] In the following description, the surface of the first region 110 of the holding substrate 100 is the XY plane parallel to the X-axis and the Y-axis, and the axis perpendicular to the XY plane is the Z-axis. In addition, the direction from right to left among the directions parallel to the X-axis in FIG. 1 may be called the X+ direction, and the direction opposite to the X+ direction may be called the X- direction. In addition, the direction from bottom to top among the directions parallel to the Y-axis in FIG. 1 may be called the Y+ direction, and the direction opposite to the Y+ direction may be called the Y- direction. In addition, the direction parallel to the Z-axis in FIG. 1 toward the paper surface may be called the Z+ direction, and the direction opposite to the Z+ direction may be called the Z- direction.

[0014] First Embodiment A plurality of light emitting elements D held on the holding substrate 100 shown in FIG. 1 are transferred to a transferred substrate 200 (see FIG. 4).

[0015] <Light emitting element> The light-emitting element D emits light of a predetermined color. The light-emitting element D is an inorganic light-emitting diode (LED: Light Emitting Diode) chip having a size of about 3 μm or more and 300 μm or less when viewed from a direction perpendicular to the first surface 101, and is called a micro LED. The display device 10 having a micro LED in each pixel is also called a micro LED display device. Note that the "micro" in micro LED does not limit the size of the inorganic light-emitting diode. The light-emitting element D may also be a mini LED.

[0016] The light-emitting element D has a laminated structure in which a first electrode connection layer, a light-emitting layer, and a second electrode connection layer (not shown) are laminated in this order. The light-emitting element D has the above-mentioned laminated structure formed by growing semiconductor crystals on a growth substrate. When the light-emitting layer is a gallium nitride material (GaN), the first electrode connection layer is, for example, N-type GaN, and the second electrode connection layer is P-type GaN. By passing a current through the first electrode connection layer and the second electrode connection layer of the light-emitting element D, the light-emitting layer emits light of a predetermined color. The light emitted by the light-emitting element D may be any color, such as red, blue, yellow-green, or green. Specifically, the central wavelength of each color of light emitted from the light-emitting element D is about 610 nm for red, about 470 nm for blue, about 505 nm for green, or 570 nm for yellow-green.

[0017] <Holding board> The holding substrate 100 is a plate-shaped substrate. As shown in FIG. 1, the holding substrate 100 has a first region 110 in the center of the holding substrate 100, an edge 102A which is the outer edge of the holding substrate 100, and an edge 102B which is the outer edge of the holding substrate 100 on the opposite side of the edge 102A with the first region 110 sandwiched therebetween. The holding substrate 100 is made of a material having light-transmitting properties. The holding substrate 100 is a so-called growth substrate for growing crystals of a semiconductor thin film. The holding substrate 100 is, for example, a sapphire substrate. The holding substrate 100 is a so-called patterned sapphire substrate in which a plurality of convex portions 122 are formed in a pattern on the second surface 120.

[0018] The holding substrate 100 is not limited to a growth substrate, and may be a transfer substrate that temporarily holds the light-emitting element D for transport. In this case, the holding substrate 100 is made of a plate material such as a glass-based material or a resin-based material, and holds the light-emitting element D on the second surface 120 via, for example, an adhesive sheet. Hereinafter, the holding substrate 100 will be described as a growth substrate.

[0019] <First area> 1 and 2, the first region 110 includes a plurality of first sections 112 and a plurality of second sections 114. In this embodiment, the center 116 of the first region 110 coincides with the position of the center of the holding substrate 100 when viewed from the Z+ direction.

[0020] <First Section> As shown in FIG. 2, FIG. 3A, and FIG. 3B, the first section 112 has a flat first surface 101 parallel to the XY plane. As shown in FIG. 2, the first section 112 is provided in a part of the gap between the second sections 114 when viewed from the Z+ direction. The first section 112 is provided in a part of the lattice lines formed by the gaps between the second sections 114. As shown in FIG. 2, the first section 112 has a cross shape when viewed from the Z+ direction. The width w of the first section 112 provided in the gap between the second sections 114 in the X+ direction along the surface of the first surface 101 is smaller than the interval d between the second sections 114 as shown in FIG. 3A and FIG. 3B. The shape of the first section 112 when viewed from the Z+ direction may be, for example, a shape formed by combining two straight lines.

[0021] As shown in Figs. 3A and 3B, the first surface 101 of the first section 112 has a smaller difference in height of undulations than the second surface 120 of the second section 114. The first surface 101 of the first section 112 is, for example, a smooth surface. In Fig. 3A, the first surface 101 is a smooth surface at a position higher in the Z direction than the second surface 102. In Fig. 3B, the first surface 101 is a smooth surface lower in the Z direction than the second surface 102. Since the first surface 101 has a smaller difference in height of undulations than the second surface 102, the first section 112 has a higher light transmittance than the second section 114. The first section 112 transmits a predetermined amount of light between the first surface 101 and the surface opposite to the first surface 101.

[0022] As shown in FIG. 1, a plurality of first sections 112 are provided in the first region 110. The plurality of first sections 112 are provided at positions that are point symmetrical with respect to the center 116 of the first region 110. For example, when the plurality of first sections 112 have a first section 112A and a first section 112B, the first section 112A is provided on the edge 102A side in the X+ direction and the Y+ direction as viewed from the center 116 of the first region 110, and the first section 112B is provided on the edge 102B side in the X- direction and the Y- direction as viewed from the center 116, opposite the edge 102A sandwiching the first region 110. The first section 112 is surrounded by the second section 114 as shown in FIG. 2. In addition, when the holding substrate 100 includes a light-emitting element D on the second surface 120 of the second section 114, the first section 112 is provided across a plurality of gaps formed by the plurality of light-emitting elements D.

[0023] <Second Section> As shown in Figs. 2, 3A, and 3B, the second sections 114 are sections having second surfaces 120 when viewed from the Z+ direction. The second sections 114 are arranged at predetermined intervals when viewed from the Z+ direction. As shown in Fig. 1, the second sections 114 are arranged in a lattice pattern when viewed from the Z+ direction. As shown in Figs. 3A and 3B, the second surface 120 has a greater difference in height between the undulations of the convex portions 122 than the first surface 101. The second surface 120 has a lower light transmittance than the first surface 101 because the undulations of the convex portions 122 cause light passing through the second surface 120 to be reflected.

[0024] The convex portions 122 of the second surface 120 are formed by light-reflecting structures that are periodically formed as a fine pattern. The light-reflecting structures have, for example, a cone, hemisphere, pyramid, or column shape that protrudes in a direction perpendicular to the second surface 120.

[0025] The convex portion 122 of the second surface 120 can be formed by, for example, the same process as that for forming a PPS (Patterned Sapphire Substrate). The convex portion 122 of the second surface 120 can be formed by, for example, an etching process technique or a so-called nanoimprint technique.

[0026] In FIG. 3A, the case where the convex portion 122 of the second surface 120 is formed by dry etching will be described below. The surface of the first region 110 of the holding substrate before the dry etching may be a smooth surface, or may be a surface on which unevenness has been formed in advance in a pattern. When using a holding substrate 100 in which the surface of the first region 110 before the dry etching is a smooth surface, the first section 112 is covered with a photoresist, and the second section 114 is not covered with a photoresist. In this case, the first section 112 is not dry etched and remains a smooth surface, and the second surface 120 of the second section 114 is dry etched to form a pattern of the convex portion 122.

[0027] 3B, when a holding substrate having a pattern of the convex portions 122 formed on the surface of the first region 110 is used, the first section 112 is not covered with photoresist, and the second section 114 is covered with photoresist. In this case, the first section 112 is dry-etched to make the first surface 101 a smooth surface, and the second surface 120 of the second section 114 is not dry-etched, and the pattern of the convex portions 122 remains. In this manner, the convex portions 122 of the second surface 120 are formed by dry etching. In addition, the mask used in the dry etching process can be formed, for example, by applying photoresist to the entire surface of the first region 110 of the holding substrate 100 to form a photoresist film, and exposing the area of ​​the photoresist film corresponding to either the first section 112 or the second section 114 to light by lithography.

[0028] <Transferred board> The transferred substrate 200 is a plate-shaped substrate as shown in Fig. 4. The transferred substrate 200 becomes, for example, an array substrate of the display device 10. The transferred substrate 200 has a transferred region 210 to which light-emitting elements D are transferred, thereby forming a display region. As shown in Fig. 4, the transferred substrate 200 has a transferred region 210, a peripheral region 214, and a plurality of second alignment marks 203. The transferred substrate 200 is, for example, an array substrate in which a TFT (Thin Film Transistor) circuit, a signal line, and a scanning line are formed in the display region.

[0029] The transferred region 210 includes a plurality of pixels to form a display region. The light-emitting element D is transferred to a predetermined position in the transferred region 210. The transferred region 210 has a size equivalent to that of the first region 110 of the holding substrate 100 when viewed from the Z+ direction. The transferred region 210 may include other light-emitting elements that are transferred before the light-emitting element D. The peripheral region 214 is provided on the outer periphery of the transferred region 210.

[0030] 4, the multiple second alignment marks 203 are provided on a surface that is visible together with the surface of the transferred region 210 when the transferred substrate 200 is viewed from the Z+ direction. The multiple second alignment marks 203 are provided at positions that are point-symmetric with respect to the center 212 of the transferred region 210. The multiple second alignment marks 203 are provided, for example, in the peripheral region 214. The multiple second alignment marks 203 are not limited to being provided in the peripheral region 214, and may be provided in the transferred region 210. In this case, the multiple second alignment marks 203 are provided at positions corresponding to the multiple first alignment marks 103 of the holding substrate 100.

[0031] 4, the second alignment mark 203A is provided in the peripheral region 214, for example, in the X+ direction and the Y+ direction as viewed from the center 212 of the transferred region 210, and the second alignment mark 203B is provided in the peripheral region 214, in the X- direction and the Y- direction as viewed from the center 212 of the transferred region 210, on a line connecting the second alignment mark 203B and the center 212 of the transferred region 210. That is, the second alignment mark 203A and the second alignment mark 203B are provided in the peripheral region 214 of the transferred substrate 200 at diagonal positions sandwiching the transferred region 210 with the center 212 of the transferred region 210 as the center. In addition, the second alignment mark 203A and the second alignment mark 203B are not limited to being positioned diagonally across the transported region 210, and may be arranged so that the line connecting the second alignment mark 203A and the second alignment mark 203B passes through the center 212 of the transported region 210 and is parallel to any one of the outer edges of the transported region 210.

[0032] The second alignment mark 203 is formed in a metal layer in which a circuit is formed. The second alignment mark 203 is provided in the metal layer in which a circuit is formed, among the laminated structure of the transferred substrate 200. The transferred substrate 200 can precisely determine the position of an electrode for connecting to the light-emitting element D, depending on the position of the second alignment mark 203. The second alignment mark 203 may be provided in any of a plurality of metal layers provided in the transferred substrate 200. The second alignment mark 203 may be formed, for example, in a metal layer in which a so-called gate electrode layer or source electrode layer is formed.

[0033] When the light emitting element D is transferred to the transferred substrate 200, it becomes the display device 10. The display device 10 displays an image by controlling a plurality of pixels. The pixel includes the light emitting element D that emits a plurality of different color lights. The display device 10 includes a plurality of pixels on the transferred substrate 200.

[0034] The pixels are arranged in a matrix. Each pixel includes, for example, a light-emitting element that emits blue light, a light-emitting element that emits red light, and a light-emitting element that emits green light. In the following description, the color of light emitted by the light-emitting element D is not specified.

[0035] <Manufacturing method of the display device according to the first embodiment> A manufacturing method of the display device according to the first embodiment will be described below with reference to Figs. 5A to 8. Fig. 5A is a conceptual diagram showing a step of acquiring a first reference position in the manufacturing method of the display device. Fig. 5B is a conceptual diagram showing a step of acquiring a second reference position in the manufacturing method of the display device. Fig. 5C is a conceptual diagram showing a positioning step in the manufacturing method of the display device. Fig. 5D is a conceptual diagram showing a step of pressing a holding substrate against a transferred substrate in the manufacturing method of the display device. Fig. 6 is a conceptual plan view of a holding substrate in the manufacturing method of the display device. Fig. 7 is a conceptual plan view of a transferred substrate in the manufacturing method of the display device. Fig. 8 is a conceptual plan view showing a state in which the holding substrate and the transferred substrate are aligned in the manufacturing method of the display device. The manufacturing method of the display device includes a step of acquiring a first reference position of the holding substrate, a step of acquiring a second reference position of the transferred substrate, and a step of aligning the holding substrate and the transferred substrate.

[0036] The manufacturing method of the display device is performed by using an alignment device (not shown). The alignment device includes a camera C1, a camera C2, a light L, a handler H, a table T, and an image processing unit and a control unit (not shown). The camera C1 captures the entire surface of the holding substrate 100 opposite to the surface having the first region 110. The camera C2 captures the entire surface of the transferred substrate 200 having the transferred region 210. The light L irradiates a predetermined amount of light onto the first region 110 of the holding substrate 100. The light L may have a dimming function. As shown in FIG. 5A, the handler H can hold the holding substrate 100 in the air, and can move the holding substrate 100 in the Z direction while holding the holding substrate 100 in the air. As shown in FIG. 5B, the table T can hold the transferred substrate 200, and can move in the X direction and the Y direction while holding the transferred substrate 200. Here, the table T holds the transferred substrate 200 in an orientation in which the transferred region 210 is in the Z+ direction. The table T is movable in the X-axis direction and the Y-axis direction. The table T includes the handler H in its movable range. The table T may further be rotatable around the Z-axis. The image processing unit performs predetermined image processing on the image data captured by the camera C1 and the image data captured by the camera C2. The control unit controls each part of the alignment device.

[0037] 5A, the holding substrate 100 is held by the handler H so that the surface of the first region 110 faces the Z-direction. Here, the holding substrate 100 held by the handler H includes a light L on the surface side that holds the light emitting element D, and a camera C1 on the surface side of the holding substrate 100 opposite to the surface including the first region 110.

[0038] 5B, the transferred substrate 200 is held on a table T of an alignment device in such a direction that the orthogonal direction to the surface of the transferred region 210 is the Z+ direction. The transferred substrate 200 held on the table T is provided with a camera C2 on the Z+ direction side. The camera C2 captures an image of the transferred substrate 200 held on the table T. Image data captured by the camera C2 is sent to an image processing unit.

[0039] <Step of obtaining the first reference position> In the step of acquiring the first reference position, as shown in FIG. 5A, the alignment device irradiates a predetermined amount of light from the light L toward the first region 110 of the holding substrate 100, and captures an image of the holding substrate 100 in a state where the light is irradiated from the light L, using a camera C1. The image data captured by the camera C1 is sent to an image processing unit. The image processing unit processes the image data sent from the camera C1 to recognize the multiple first alignment marks 103. In addition, the image processing unit acquires the first reference position 130 from the image data based on the recognized multiple first alignment marks 103, as shown in FIG. 6.

[0040] Specifically, the alignment device irradiates the holding substrate 100 with light L from the surface opposite to the first region 110 of the holding substrate 100. Of the light irradiated from the light L, the light irradiated to the first section 112 of the holding substrate 100 is transmitted from the first surface 101 to the surface opposite to the first surface 101. Also, of the light irradiated from the light L, the light irradiated to the second section 114 of the holding substrate 100 is reflected by the undulations of the convex portion 122 of the second surface 120 and attenuated. As a result, the amount of light irradiated from the light L to the second section 114 of the holding substrate 100 and transmitted in the opposite direction to the surface of the first region 110 is smaller than the amount of light irradiated to the first section 112 of the holding substrate 100 and transmitted in the opposite direction to the surface of the first region 110. That is, the light irradiated from the light L to the second section 114 of the holding substrate 100 is cut off so that the amount of light passing through the opposite side to the surface of the first region 110 is reduced to a predetermined amount or less. Here, the "predetermined amount of light" is a predetermined amount of light. Of the light passing through the second section 114, the light passing through the first section 114 is captured by the camera C1 provided on the opposite side of the first section 101.

[0041] The image processing unit recognizes the portions of the transferred substrate 200 corresponding to the first section 112A and the first section 112B as the first alignment mark 103A and the first alignment mark 103B, respectively, based on the image data for the first section 112A and the first section 112B. The image processing unit divides the image data captured by the camera C1 into a plurality of image regions and acquires the luminance of each image region. The image processing unit recognizes the plurality of image regions having a predetermined luminance or more among the acquired plurality of image regions as the plurality of first alignment marks 103, respectively, and acquires the first reference position 130. Here, the predetermined luminance is a luminance that is specified in advance. The image region corresponding to the first section 112 on the image data has a predetermined amount of light transmitted therethrough and has a predetermined luminance or more, and the image region corresponding to the second section 114 of the image data has a luminance lower than that of the image region corresponding to the first section 112. The image processing unit combines image areas of the image data that have a predetermined brightness or more, recognizes the first alignment mark 103 based on the shape of the combined image area, and obtains the coordinates of the position of the center 104 of the first alignment mark 103. More specifically, the image processing unit obtains the coordinates of the position of the center 104A of the shape of the image area recognized as the first alignment mark 103A in the image data, and the coordinates of the position of the center 104B of the shape of the image area recognized as the first alignment mark 103B.

[0042] Thereafter, the image processing unit acquires a specific position based on the coordinates of the position of the center 104A of the first alignment mark 103A and the coordinates of the position of the center 104B of the first alignment mark 103B, and sets the specific position as the first reference position 130. The specific position acquired by the image processing unit is, for example, a position intermediate between the coordinates of the position of the center 104A of the first alignment mark 103A and the coordinates of the position of the center 104B of the first alignment mark 103B. In this case, the first reference position 130 is acquired within the first region 110. The image processing unit acquires the coordinates of the acquired first reference position 130. The image processing unit may acquire the coordinates of the acquired first reference position 130 in the X direction and the Y direction in the alignment device. The first reference position 130 is not limited to one point, and may be a point at a plurality of different positions.

[0043] <Step of obtaining the second reference position> In the step of acquiring the second reference position, as shown in FIG. 5B, the alignment device captures an image with the camera C2. As shown in FIG. 7, the image processing unit processes the image data captured by the camera C2 to recognize the second alignment mark 203. The image processing unit acquires the coordinates of the positions of the centers 204 of the recognized second alignment marks 203. The image processing unit acquires the second reference position 220 based on the coordinates of the positions of the centers 204 of the acquired second alignment marks 203. It does not matter whether the step of acquiring the second reference position and the step of acquiring the first reference position are performed in chronological order. The step of acquiring the second reference position and the step of acquiring the first reference position may be performed at the same time.

[0044] Specifically, in the step of acquiring the second reference position, the alignment device captures an image of the transferred substrate 200 with the camera C2. The image processing unit acquires the coordinates of the position of the center 204A of the second alignment mark 203A provided on the edge 202A side of the transferred substrate 200 and the coordinates of the position of the center 204B of the second alignment mark 203B provided on the edge 202B side of the transferred substrate 200 based on the image data captured by the camera C2. The image processing unit acquires a specific position based on the coordinates of the position of the center 204A of the second alignment mark 203A and the coordinates of the position of the center 204B of the second alignment mark 203B, and sets the specific position as the second reference position 220. The specific position acquired by the image processing unit is, for example, an intermediate position between the coordinates of the position of the center 204A of the second alignment mark 203A and the coordinates of the position of the center 204B of the second alignment mark 203B. The image processing unit acquires the coordinates of the acquired second reference position 220. The image processing unit may acquire the coordinates in the X direction and the Y direction in the alignment device of the acquired second reference position 220. Note that the second reference position 220 is not limited to one point, and may be a plurality of points at different positions.

[0045] <Alignment step> In the step of aligning, as shown in Fig. 5C, the alignment device moves the table T holding the transferred substrate 200 in the XY directions so that the holding substrate 100 and the transferred substrate 200 are aligned. Specifically, the alignment device obtains the difference in the X direction and the difference in the Y direction between the acquired coordinates of the first reference position 130 of the holding substrate 100 and the acquired coordinates of the second reference position 220 of the transferred substrate 200. Thereafter, the alignment device moves the table T by the amount of the acquired difference in the X direction and the difference in the Y direction to align the second reference position 220 of the transferred substrate 200 with the first reference position 130 of the holding substrate 100.

[0046] <Step of pressing the holding substrate against the transferred substrate> 5D, the alignment device positions the holding substrate 100 and the transferred substrate 200, and then moves the handler H in the Z-direction. The holding substrate 100 held by the handler H descends to the position of the transferred substrate 200, and presses the light-emitting elements D held on the second surface 120 against the transferred region 210 of the transferred substrate 200 with a predetermined load in the Z-direction. By being pressed against the transferred substrate 200, the multiple light-emitting elements D come into contact with the multiple electrodes provided on the transferred substrate 200 via the low-melting point metal member.

[0047] In the manufacturing method of the display device, the holding substrate 100 is irradiated with a heating laser beam of a predetermined wavelength from a heating laser device (not shown) provided on the opposite side of the first surface 101 while pressed against the transferred substrate 200. As a result, the low melting point metal member of the transferred region 210 of the transferred substrate 200 that absorbs the irradiated heating laser beam melts and connects the light emitting element D held by the holding substrate 100 to the electrode of the transferred substrate 200. In addition, in the manufacturing method of the display device, the holding substrate 100 is irradiated with an ablation laser beam from an ablation laser device provided on the opposite side of the first surface 101 of the holding substrate 100 after being irradiated with the heating laser beam. The interface between the second surface 120 of the light emitting element D that absorbs the irradiated ablation laser beam is altered, and the second surface 120 and the light emitting element D are separated. In this way, the light emitting element D held by the holding substrate 100 is transferred to the transferred substrate 200 by the manufacturing method of the display device.

[0048] (Modification) 9 is a detailed view of a main part of a holding substrate according to a modified example. The first section 112 of the holding substrate 100 may surround a plurality of second sections 114 as shown in FIG. 9. In this case, the first section 112 is formed in the gap between the plurality of second sections 114 so as to surround the plurality of second sections 114 in a cross shape centered on the center 116 when viewed from the Z+ direction. This increases the area surrounded by the first sections 112, making it easier for the camera C1 to recognize the first alignment mark 103 formed by the light irradiated from the light L shown in FIG. 5A passing through the first surface 101. Furthermore, the first section 112 may be surrounded by a plurality of second sections 114. This makes it easier for the camera C1 to recognize the difference in luminance between the image area corresponding to the first section 112 in the image data of the holding substrate 100 captured when irradiated with light L and the image area corresponding to the second section 114, so that the coordinates of the position of the center 104 of the first alignment mark 103 can be acquired with greater accuracy. Note that the shape of the first section 112 as viewed from the Z+ direction is not limited to a cross shape, and may be a polygon such as a circle, a triangle, a rectangle, or a hexagon. Also, the shape of the first section 112 as viewed from the Z+ direction may be a combination of multiple shapes.

[0049] As described above, the manufacturing method of the display device includes a step of acquiring a first reference position on the surface of the holding substrate 100 based on the positions of the first alignment marks 103 of the holding substrate 100, a step of acquiring a second reference position 220 on the surface of the transferred substrate 200 based on the positions of the second alignment marks 203 of the transferred substrate 200, and a step of aligning the holding substrate 100 and the transferred substrate 200 so that the first reference position 130 and the second reference position 220 are aligned. The holding substrate 100 is partitioned into a plurality of first sections 112 and a plurality of second sections 114 as viewed from the Z+ direction. The second sections 114 are arranged at a predetermined interval as viewed from the Z+ direction. The first sections 112 are provided in some of the gaps between the plurality of second sections 114 as viewed from the Z+ direction. The first sections 112 have a higher light transmittance than the second sections 114. The first section 112 forms a first alignment mark 103 that transmits light when viewed from the Z+ direction.

[0050] As a result, the holding substrate 100 has the first alignment mark 103, which includes the multiple first sections 112 having a higher light transmittance than the second sections 114, and the multiple second sections 114, and therefore it is possible to recognize a predetermined amount of light passing through the first sections 112 of the first surface 101 as the first alignment mark 103. In addition, the multiple first sections 112 forming the first alignment mark 103 of the holding substrate 100 are provided in some of the gaps between the multiple second sections 114 for holding the light-emitting elements D, and unlike the conventional technology, the first alignment mark 103 is not provided in the second sections 114 which are areas for holding the light-emitting elements D, so that the number of light-emitting elements D held by the holding substrate 100 can be increased. Furthermore, since the holding substrate 100 does not have the first alignment mark 103 in the second section 114, which is the area in which the light-emitting element D is to be held, in the manufacturing process of the display device, after the light-emitting elements D are transferred en bloc from the holding substrate 100 to the transferred substrate 200, there is no need for a process of transferring replenishment light-emitting elements D to the area of ​​the transferred substrate 200 that previously had the second alignment mark 203.

[0051] The first compartment 112 may be surrounded by a number of second compartments 114 .

[0052] As a result, the first section 112 is surrounded by multiple second sections 114, so that when light is irradiated from the side opposite the first region 110 of the holding substrate 100, the difference in brightness between the area corresponding to the first section 112 on the side of the first region 110 and the area corresponding to the second section 114 can be made more clear, thereby improving the ease of recognition of the first section 112.

[0053] The first compartment 112 may surround a number of second compartments 114 .

[0054] As a result, when viewed from the Z+ direction, the first section 112 surrounds at least one of the second sections 114, thereby making the area surrounded by the first section 112 larger, and improving the ease of recognition of the first section 112.

[0055] The second sections 114 are arranged in a lattice pattern when viewed from the Z+ direction, and the first sections 112 may be provided in part of the lattice lines formed by the gaps between the second sections 114.

[0056] As a result, the first section 112 is provided in a part of a grid line formed by the gaps between multiple second sections 114 arranged in a grid pattern, so that the first section 112 can be made to have a shape and size that follows the grid line regardless of the shape and size of the second sections 114.

[0057] When viewed in the Z+ direction, the first section 112 has a first surface 101 and the second section 114 has a second surface 120 , which may be more contoured than the first surface 101 .

[0058] As a result, the second surface 120 of the second section 114 has greater undulations than the first surface 101 of the first section 112, so that the second surface 120 has a high reflectance of light from the orthogonal direction of the second surface 120, and can have a lower transmittance than the light passing between the second surface 120 and the opposite surface of the second surface 120. In addition, since the second section 114 has a high reflectance of light from the orthogonal direction of the second surface 120, it can reflect the light from the orthogonal direction of the second surface 120 in a direction other than the orthogonal direction of the second surface 120.

[0059] The multiple first sections 112 and the multiple second sections 114 of the holding substrate 100 are provided in a first region 110 of the holding substrate 100, and a first reference position 130 of the holding substrate 100 may be obtained within the first region 110.

[0060] As a result, the holding substrate 100 acquires the first reference position 130 within the first region 110, and thus by aligning it with the second reference position 220 of the transferred substrate 200, it becomes possible to align the holding substrate 100 with the transferred substrate 200. Also, since the holding substrate 100 acquires the first reference position 130 within the first region 110, it becomes possible to align the position of the light-emitting element D within the first region 110 as the first reference position 130 with the second reference position 220 of the transferred substrate 200.

[0061] The holding substrate 100 is partitioned into a plurality of first sections 112 and a plurality of second sections 114 when viewed from the Z+ direction. The first sections 112 are provided in some of the gaps between the plurality of second sections 114 when viewed from the Z+ direction. The first sections 112 have a higher light transmittance than the second sections 114. The first sections 112 form the first alignment marks 103.

[0062] As a result, the holding substrate 100 has a plurality of first sections 112 and a plurality of second sections 114, each having a higher light transmittance than the second sections 114, and therefore it becomes possible to recognize a predetermined amount of light passing through the first sections 112 of the first surface 101 as the first alignment mark 103. Also, the plurality of first sections 112 forming the first alignment marks 103 of the holding substrate 100 are provided in some of the gaps between the plurality of second sections 114 for holding the light-emitting elements D, and unlike the conventional technology, the first alignment marks 103 are not provided in the second sections 114, which are areas for holding the light-emitting elements D, so that it is possible to increase the number of light-emitting elements D held by the holding substrate 100. Furthermore, since the holding substrate 100 does not have the first alignment mark 103 in the second section 114, which is the area in which the light-emitting element D is to be held, in the manufacturing process of the display device, after the light-emitting element D held on the holding substrate 100 is transferred to the transferred substrate 200, there is no need for a process of transferring the light-emitting element D to the area of ​​the transferred substrate 200 that previously had the second alignment mark 203 in order to replenish it.

[0063] Although the preferred embodiment has been described above, the present disclosure is not limited to such an embodiment. The contents disclosed in the embodiment are merely examples, and various modifications are possible within the scope of the present disclosure. Appropriate modifications made within the scope of the present disclosure also naturally belong to the technical scope of the present disclosure.

[0064] For example, the transferred substrate may have a transferred region larger than the first region 110 of the holding substrate 100. When the transferred region includes a plurality of regions corresponding to the size of the first region 110, a plurality of second alignment marks are provided in the peripheral region of the transferred substrate for each region corresponding to the size of the first region 110, and the second reference position is obtained based on the plurality of second alignment marks for each region corresponding to the size of the first region 110. [Explanation of symbols]

[0065] 10 Display device 100 Holding board 101 Page 1 102A, 102B Edge 103, 103A, 103B First alignment mark 104, 104A, 104B Center of first alignment mark 110 1st area 112 Section 1 114 Section 2 116 Center of the First Region 120 Side 2 122 Convex 130 1st reference position 200 Transferred substrate 202A, 202B Edge 203, 203A, 203B Second alignment mark 204, 204A, 204B Center of second alignment mark 210 Transported area 212 Center of the transported area 214 Surrounding Areas 220 2nd reference position D Light emitting element d Distance between multiple light emitting elements w Width of first section C1, C2 Camera H Handler L Light T Table

Claims

1. A step of forming a plurality of light emitting elements on a supporting substrate; obtaining a first reference position on a surface of the holding substrate based on positions of a plurality of first alignment marks of the holding substrate; and aligning the holding substrate and the transferred substrate such that the first reference position of the holding substrate coincides with a second reference position on a surface of the transferred substrate; The holding substrate is divided into a plurality of first sections and a second section when viewed from one direction, When viewed from the one direction, the first section has a first surface and the second section has a second surface; the second surface includes a plurality of the light emitting elements on a plurality of convex portions arranged in a pattern; Each of the plurality of light-emitting elements is provided corresponding to a pattern of the plurality of protrusions, The first section is surrounded by the second section, The first section is provided across a plurality of gaps formed by a plurality of the light emitting elements when viewed from the one direction, The second surface has undulations with a greater difference in height than the first surface, A method for manufacturing a display device, comprising forming the first alignment mark, the first section having a higher light transmittance than the second section and through which light passes when viewed from the one direction.

2. The method for manufacturing a display device according to claim 1 , wherein the first section surrounds the second section.

3. The second sections are arranged in a lattice pattern when viewed from the one direction, The method for manufacturing a display device according to claim 1 , wherein the first sections are provided in parts of lattice lines formed by gaps between the light-emitting elements arranged in a lattice pattern.

4. A plurality of the first compartments and the second compartments are provided in a first region of the holding substrate; The method for manufacturing a display device according to claim 1 , wherein the first reference position of the holding substrate is obtained within the first region.

5. the transferred substrate includes a transferred region corresponding to the first region of the holding substrate, and a plurality of second alignment marks outside the transferred region; The method of manufacturing a display device according to claim 4 , wherein the second reference position is obtained based on a plurality of the second alignment marks.

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