Method for manufacturing display device and inorganic light emitting element holding substrate

Abstract

The present application improves the manufacturing efficiency of an LED display device that improves the performance of a display device. A manufacturing method of a display device includes a step of irradiating laser light (51) from the back surface (SS1b) side of a substrate (SS1) in a state where the substrate (SS1) and an array substrate (SUB1) are pushed against each other, and a step of electrically connecting a plurality of LED elements (20) to a plurality of terminals (30) of the array substrate (SUB1). The laser light (51) is capable of transmitting through the substrate (SS1). The substrate (SS1) has a light shielding film (LSF) formed on an element holding surface (SS1t) and having light shielding properties with respect to the laser light (51). In a plan view, the plurality of LED elements (20) are respectively arranged at positions overlapping a plurality of opening portions formed in the light shielding film (LSF).

Description

Technical Field

[0001] This invention relates to manufacturing techniques for display devices and inorganic light-emitting element holding substrates used in the manufacturing of display devices. Background Technology

[0002] As a display device, there is an LED (Light Emitting Diode) display device in which light-emitting diode elements, which are self-emissive elements, are arranged in a matrix on a substrate (see, for example, Patent Document 1 (Japanese Patent Application Publication No. 2018-517298)). Patent Document 1 describes a method for peeling the sapphire substrate from the light-emitting diode elements by irradiating a laser from the back side of the sapphire substrate after assembling the sapphire substrate on which the light-emitting diode elements are formed. Furthermore, Patent Document 2 (Japanese Patent Application Publication No. 2021-5632) describes a method for bonding the light-emitting diode elements transferred from the sapphire substrate to a transfer substrate to a circuit board after transferring the light-emitting diode elements from the sapphire substrate to the transfer substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2018-517298

[0006] Patent Document 2: Japanese Patent Application Publication No. 2021-5632 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the case of LED display devices, a number of LED elements are mounted on an array substrate. One method for mounting these LED elements onto the array substrate is to irradiate the back side of a holding substrate on which the LED elements are arranged with a laser, thereby heating the electrodes of the LED elements and electrically connecting them to the terminals of the array substrate. However, irradiating the entire array substrate with the laser can sometimes cause damage to the elements. Therefore, a technique for selectively irradiating the array substrate with the laser is needed.

[0009] The purpose of this invention is to provide a technique for improving the performance of display devices.

[0010] Methods used to solve problems

[0011] A method for manufacturing a display device according to a technical solution of the present invention includes: (a) a step of preparing a first substrate and an array substrate having a plurality of first terminals, wherein the first substrate has a first surface and a second surface opposite to the first surface, and a plurality of first inorganic light-emitting elements are arranged in a matrix on the first surface; (b) a step of pressing the first substrate and the array substrate together with the first surface of the first substrate held by a first worktable facing the array substrate held by a second worktable; and (c) a step of irradiating a laser from the second surface of the first substrate while the first substrate and the array substrate are pressed together, and electrically connecting the plurality of first inorganic light-emitting elements to the plurality of first terminals of the array substrate. The laser is transmissible through the first substrate. The first substrate has a first light-shielding film formed on the first surface and having light-shielding properties against the laser. In a plan view, the plurality of first inorganic light-emitting elements are respectively disposed at positions overlapping with the plurality of first openings formed in the first light-shielding film.

[0012] Another embodiment of the present invention provides an inorganic light-emitting element holding substrate, comprising: a substrate having a first surface and a second surface opposite to the first surface; a light-shielding film formed on the first surface; and a plurality of inorganic light-emitting elements held on the first surface. The substrate is light-transmitting. The plurality of inorganic light-emitting elements are respectively disposed in a plurality of openings formed in the light-shielding film. Attached Figure Description

[0013] Figure 1 This is a plan view showing a structural example of a display device according to one embodiment.

[0014] Figure 2 It means Figure 1 The circuit diagram shown is an example of the structure of the circuit around the pixel.

[0015] Figure 3 It means in Figure 1 An enlarged cross-sectional view of an example of the peripheral structure of the LED elements arranged in each of the multiple pixels of the display device shown.

[0016] Figure 4 It means relative to Figure 3 An enlarged cross-sectional view of a modified example of the LED element shown.

[0017] Figure 5 It means Figure 1 A flowchart illustrating the manufacturing process of the display device.

[0018] Figure 6 It means in Figure 5 The diagram shows a schematic plan view of the substrate prepared during the LED holding substrate preparation process.

[0019] Figure 7 It means in Figure 5 A schematic cross-sectional view of the array substrate SUB1 prepared in the array substrate preparation process shown.

[0020] Figure 8 yes Figure 6 Enlarged cross-sectional views of the various substrates shown.

[0021] Figure 9 It is a schematic representation of... Figure 5 The diagram shows a cross-sectional view of the substrate and array substrate in which the first inorganic light-emitting element is arranged, which are pressed together in the first substrate pressing process.

[0022] Figure 10 It is Figure 9 The enlarged cross-sectional view shows the state of the connection interface between the LED element and the array substrate.

[0023] Figure 11 It is a schematic representation of... Figure 5 An enlarged cross-sectional view showing the state of the conductive joint being heated by a laser during the first laser irradiation process.

[0024] Figure 12 It means for Figure 11 An enlarged sectional view of the research example.

[0025] Figure 13 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state after the holding substrate has been peeled from the plurality of first inorganic light-emitting elements in the first holding substrate peeling process.

[0026] Figure 14 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state in which the substrate and the array substrate on which the second inorganic light-emitting element is arranged are pressed during the second substrate pressing process.

[0027] Figure 15 It is Figure 14 The enlarged cross-sectional view shows the state of the connection interface between the LED element and the array substrate.

[0028] Figure 16 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state after the holding substrate has been peeled from the plurality of second inorganic light-emitting elements in the second holding substrate peeling process.

[0029] Figure 17 It is a schematic representation of... Figure 5The cross-sectional view shown is of the state in which the substrate and the array substrate on which the second inorganic light-emitting element are arranged are pressed during the third substrate pressing process.

[0030] Figure 18 It is Figure 17 The enlarged cross-sectional view shows the state of the connection interface between the LED element and the array substrate.

[0031] Figure 19 It means relative to Figure 8 An enlarged cross-sectional view of a modified example of the substrate shown.

[0032] Figure 20 It means that it was used. Figure 19 In the manufacturing method of the display device that holds the substrate shown, relative to Figure 11 An enlarged sectional view of a modified example.

[0033] Label Explanation

[0034] 5. Control Circuit

[0035] 6. Drive Circuit

[0036] 10. SS1, SS2, SS3, SS4 substrate

[0037] 10b, 10f, 20b, 20f face

[0038] 11 Inorganic insulating layer

[0039] 12, 13 Organic insulating layers

[0040] 20, 20M1 LED components (inorganic light-emitting components)

[0041] 20E electrode

[0042] 20EA anode electrode

[0043] 20EK cathode electrode

[0044] 21. First Inorganic Light-Emitting Element

[0045] 22. Second Inorganic Light-Emitting Element

[0046] 23 Third Inorganic Light-Emitting Element

[0047] 30, 30H, 30L, 31, 32, 33 terminals

[0048] 40, 41, 42, 43 Conductive joints

[0049] 51 laser

[0050] Workbench 61, 62

[0051] 61h, 62h maintenance surface

[0052] 70 Component Holding Part

[0053] 71. Protrusion

[0054] 72 Adhesive layer

[0055] BCT output switch

[0056] Cad auxiliary capacitor

[0057] Cs holding capacitor

[0058] DA display area

[0059] DRT drive transistor

[0060] DSP1 display device

[0061] EK cathode electrode

[0062] GL, GLA, GLB scan signal lines

[0063] GLR reset wiring

[0064] Gsb, Gsr, Gss control signals

[0065] IC Driver

[0066] LED Micro

[0067] PFA surrounding area

[0068] PIX pixels

[0069] PVD and PVS potentials

[0070] RST Reset Switch

[0071] Back of SS1b, SS2b, SS3b, SSHb

[0072] SS1t, SS2t, SS3t, SSHt component holding surfaces

[0073] SST Pixel Switch

[0074] SUB1 and SUB2 array substrates

[0075] Subb side (side 2)

[0076] Subt (Page 1)

[0077] VL image signal line

[0078] Vsg image signal Detailed Implementation

[0079] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the disclosure is merely an example, and forms that can be readily conceived by those skilled in the art with appropriate modifications while maintaining the spirit of the invention are naturally included within the scope of the present invention. In addition, the drawings may schematically represent the width, thickness, shape, etc., of various parts compared to the actual form in order to make the description clearer, but this is merely an example and does not limit the interpretation of the present invention. Furthermore, in this specification and the drawings, there are instances where elements described in the prior drawings are given the same or related reference numerals, and detailed descriptions are appropriately omitted.

[0080] In the following embodiments, a micro-LED display device incorporating multiple micro-LED elements will be described as an example of a display device using multiple inorganic light-emitting elements. Micro-LED elements have the advantage of being able to display high-resolution images because their size (outer diameter) is smaller than that of conventional LED elements.

[0081] Furthermore, light-emitting diode elements, which are self-emissive elements, include organic light-emitting diode elements (OLEDs). The inorganic light-emitting diode elements (micro-LED elements) described in the following embodiments are distinguished from organic light-emitting diode elements.

[0082] <Display Device>

[0083] First, a structural example of the micro LED display device, which is the display device of this embodiment, will be described. Figure 1 This is a plan view showing a structural example of a display device according to one embodiment. Figure 1 In the diagram, double-dotted lines represent the boundary between the display area DA and the surrounding area PFA, the control circuit 5, the driving circuit 6, and multiple pixels PIX. Figure 2 It means Figure 1 The circuit diagram shown is an example of the structure of the circuit around the pixel.

[0084] like Figure 1 As shown, the display device DSP1 of this embodiment has a display area DA, a peripheral area PFA that surrounds the display area DA in a frame shape, and a plurality of pixels PIX arranged in a matrix within the display area DA. Furthermore, the display device DSP1 has a substrate 10, a control circuit 5 formed on the substrate 10, and a drive circuit 6 formed on the substrate 10.

[0085] Control circuit 5 is a control circuit that controls the driving of the display function of display device DSP1. For example, control circuit 5 is a driver IC (Integrated Circuit) mounted on substrate 10. Figure 1 In the example shown, the control circuit 5 is arranged along one of the short sides of the four sides of the substrate 10. Furthermore, in this embodiment, the control circuit 5 includes an image signal line VL (refer to...) connected to the plurality of pixels PIX. Figure 2 The signal line driving circuit is used to drive the signal. However, the location and structure of the control circuit 5 are not limited to this. Figure 1 The examples shown have various variations. For example, in Figure 1 In some cases, a flexible substrate or other circuit board is connected to the position indicated as control circuit 5, and the aforementioned driver IC is mounted on the circuit board. Furthermore, for example, there are cases where the signal line driving circuit that drives the image signal line VL is formed differently from the control circuit 5.

[0086] Driving circuit 6 is a circuit that drives the scan signal lines GL in multiple pixels (PIX). Driving circuit 6 drives the multiple scan signal lines GL based on control signals from control circuit 5. Figure 1 In the example shown, the driving circuits 6 are arranged along two of the long sides of the four sides of the substrate 10. However, the position and structure of the driving circuits 6 are not limited to this example. Figure 1 The examples shown have various variations. For example, in Figure 1 In some cases, a flexible substrate or other circuit board is connected to the position indicated as control circuit 5, and the aforementioned drive circuit 6 is mounted on the circuit board.

[0087] Next, use Figure 2 An example of the circuit structure for a pixel PIX will be explained. Additionally, in... Figure 2 The text represents and illustrates a pixel PIX, but... Figure 1 The multiple pixel PIX shown have the same characteristics as... Figure 2 The same circuit is shown for the pixel PIX. Hereinafter, the circuit including switches, capacitors, and LED elements 20 in the pixel PIX will be referred to as the pixel circuit. The pixel circuit is based on the control circuit 5 (see reference 5). Figure 1 The circuit uses a voltage signal to control the light-emitting state of the LED element 20 by supplying the image signal Vsg.

[0088] like Figure 2 As shown, the pixel PIX includes an LED element 20. The LED element 20 is the aforementioned miniature light-emitting diode. The LED element 20 has an anode electrode 20EA (see below). Figure 3 ) and cathode electrode 20EK (see below) Figure 3 The anode electrode 20EA and cathode electrode 20EK of the LED element 20 are electrically connected to the terminal 30 of the pixel PIX. Figure 2 In the example shown, the cathode electrode 20EK of LED element 20 is connected to terminal 30L, and the anode electrode 20EA of LED element 20 is connected to terminal 30H. Terminal 30L is supplied with a relatively low fixed potential (low potential), i.e., potential PVS, and terminal 30H is supplied with a higher fixed potential (high potential), i.e., potential PVD, than the potential supplied to terminal 30L.

[0089] The pixel PIX includes an output switch BCT, a driving transistor DRT, and a pixel switch SST. The output switch BCT is a transistor that controls the emission time of the LED element 20 in response to a control signal Gsb supplied from the driving circuit 6. The driving transistor DRT is a transistor that controls the amount of driving current supplied to the anode electrode of the LED element 20 based on the image signal Vsg. The pixel switch SST is a transistor that controls the connection state (on or off) between the pixel circuit and the image signal line VL in response to the control signal Gss. Furthermore, the driving circuit 6 includes a reset switch RST that controls the input of a reset potential. The output switch BCT, driving transistor DRT, pixel switch SST, and reset switch RST are, for example, thin-film transistors. When the pixel switch SST is in the on state, the pixel circuit receives the image signal Vsg from the image signal line VL.

[0090] The drive circuit 6 includes a shift register circuit (not shown), an output buffer circuit, etc. The drive circuit 6 is based on the control circuit 5 (see reference 5). Figure 1 The horizontal scan start pulse transmitted is used to output pulses, and control signals Gss, Gsb and Gsr are output.

[0091] Multiple scan signal lines GL include scan signal lines GLA and GLB, and a reset wiring GLR. Each scan signal line GL extends in the X direction. Scan signal line GLA is connected to the gate electrode of output switch BCT. When a control signal Gsb is supplied to scan signal line GLA, output switch BCT becomes active. Scan signal line GLB is connected to the gate electrode of pixel switch SST. When a control signal Gss is supplied to scan signal line GLB, pixel switch SST becomes active. Reset wiring GLR is connected between output switch BCT and drive transistor DRT, and to the drain electrode of reset switch RST. When a control signal Gsr, serving as a reset signal, is supplied to the gate electrode of reset switch RST, reset wiring GLR is supplied with a reset potential.

[0092] The pixel PIX includes a storage capacitor Cs and an auxiliary capacitor Cad. Each of the storage capacitor Cs and the auxiliary capacitor Cad is a capacitor. The storage capacitor Cs is connected between the gate electrode of the driving transistor DRT and the terminal 30H. The auxiliary capacitor Cad is connected between the source electrode of the output switch BCT and the terminal 30H. The auxiliary capacitor Cad is a capacitive element for adjusting the amount of light emission current, and as a modified example, the auxiliary capacitor Cad may not be provided.

[0093] <Peripheral Structure of LED Element>

[0094] Next, the Figure 1 peripheral structure of the LED element disposed in the pixel PIX shown in the above will be described. Figure 3 is an enlarged cross-sectional view showing an example of the peripheral structure of the LED element disposed in each of the plurality of pixels of the display device shown in the Figure 1 above. Figure 4 is an enlarged cross-sectional view showing a modified example of the LED element shown in the Figure 3 above.

[0095] Figure 3 The array substrate SUB1 shown in the above is a substrate including a substrate 10 and a plurality of insulating layers stacked on the substrate 10. The plurality of insulating layers included in the array substrate SUB1 include an inorganic insulating layer 11, an organic insulating layer 12, and an organic insulating layer 13. In addition, the array substrate SUB1 includes various circuits included in the pixel PIX described with reference to Figure 2 . The substrate 10 has a surface 10f and a surface 10b on the opposite side of the surface 10f. The inorganic insulating layer 11, the organic insulating layer 12, and the organic insulating layer 13 are respectively stacked on the surface 10f of the substrate 10.

[0096] Each of the inorganic insulating layer 11, the organic insulating layer 12, and the organic insulating layer 13 may be a stacked film composed of a plurality of stacked insulating films. For example, the semiconductor layers of the thin film transistors constituting the output switch BCT, the driving transistor DRT, and the pixel switch SST shown in Figure 2 are formed in the inorganic insulating layer 11. A part of the plurality of inorganic insulating films constituting the inorganic insulating layer 11 is used as a base layer for forming the thin film transistors, and the other part is used as a gate insulating film of the thin film transistors.

[0097] As shown in Figure 3 , the LED element 20 is mounted on the array substrate SUB1. The LED element 20 has a surface 20f and a surface 20b on the opposite side of the surface 20f. Further, the LED element 20 includes a plurality (in Figure 3there are two electrodes 20E. The plurality of electrodes 20E include an anode electrode 20EA and a cathode electrode 20EK. The anode electrode 20EA is connected to the terminal 30H via a conductive joint member 40. The cathode electrode 20EK is connected to the terminal 30L via a conductive joint member 40. The conductive joint member 40 is made of, for example, solder. In Figure 3 one LED element is illustrated, but a plurality of LED elements are mounted in a matrix on the array substrate SUB1. The display device DSP1 displays an image by driving the plurality of LED elements 20 mounted on the array substrate SUB1. Light emitted from the LED elements 20 is emitted from, for example, the surface 20b side.

[0098] In addition, in Figure 3 as an example of the LED element 20, an example in which both the anode electrode 20EA and the cathode electrode 20EK are arranged on the surface 20f is shown. However, there are various modifications to the structure of the LED element 20. For example, in Figure 4 in the case of the LED element 20M1 shown, the cathode electrode 20EK is provided on the surface 20b, and the anode electrode 20EA is provided on the surface 20f. When the Figure 3 the LED element 20 shown is replaced with Figure 4 in the case of the LED element 20M1 shown, the terminal 30L connected to the cathode electrode 20EK is provided on the surface 20b of the LED element 20M1 (refer to Figure 3 ).

[0099] <Method for Manufacturing Display Device>

[0100] Next, the manufacturing method of the display device DSP1 shown in Figure 1 will be described. Figure 5 is an explanatory diagram showing the flow of the manufacturing steps of the display device shown in Figure 1 . In the process illustrated in Figure 5 , a method of sequentially mounting three types of LED elements for red, green, and blue on an array substrate will be described as an example. However, as will be described later as a modification, a method may also be adopted in which a holding substrate on which a plurality of types of LED elements 20 are arranged in a matrix is used to collectively mount the plurality of types of LED elements onto the array substrate.

[0101] <LED Holding Substrate Preparing Step and Array Substrate Preparing Step>

[0102] In the LED holding substrate preparing step shown in Figure 5 , the substrates SS1, SS2, and SS3 shown in Figure 6 are prepared. Figure 6 is a diagram showing the structure on Figure 5The diagram shows a schematic plan view of the substrates prepared in the LED holding substrate preparation process. Substrates SS1, SS2, and SS3 each have an upper surface and a lower surface. Furthermore, each of the substrates SS1, SS2, and SS3, serving as LED holding substrates, has a portion on one of its upper and lower surfaces (in...). Figure 6 In the example shown, the upper surface has multiple LED elements arranged in a matrix.

[0103] In detail, different types of LED elements are arranged on substrates SS1, SS2, and SS3. In other words, substrates SS1, SS2, and SS3 are LED holding substrates that hold multiple LED elements. For example, on the element holding surface SS1t of substrate SS1, a first inorganic light-emitting element 21, which is one of a red LED element, a green LED element, and a blue LED element, is arranged. On the element holding surface SS2t of substrate SS2, a second inorganic light-emitting element 22, which is an LED element different from the first inorganic light-emitting element 21, is arranged. On the element holding surface SS3t of substrate SS3, a third inorganic light-emitting element 23, which is an LED element different from the first inorganic light-emitting element 21 and the second inorganic light-emitting element 22, is arranged.

[0104] In this process, for example, electrodes 20E of the first inorganic light-emitting element 21, the second inorganic light-emitting element 22, and the third inorganic light-emitting element 23 are pre-deposited. Figure 3 The conductive connector 40 is shown. However, as a variation, there is a pre-connected connector on the terminal 30. Figure 3 The case of the conductive connector 40 shown.

[0105] On the element holding surface SS1t of substrate SS1, a plurality of first inorganic light-emitting elements 21 are arranged in a matrix. No second inorganic light-emitting elements 22 or third inorganic light-emitting elements 23 are disposed on the element holding surface SS1t of substrate SS1. On the element holding surface SS2t of substrate SS2, a plurality of second inorganic light-emitting elements 22 are arranged in a matrix. No first inorganic light-emitting elements 21 or third inorganic light-emitting elements 23 are disposed on the element holding surface SS2t of substrate SS2. On the element holding surface SS3t of substrate SS3, a plurality of third inorganic light-emitting elements 23 are arranged in a matrix. No first inorganic light-emitting elements 21 or second inorganic light-emitting elements 22 are disposed on the element holding surface SS3t of substrate SS3. Substrates SS1, SS2, and SS3 are, for example, sapphire substrates. The first inorganic light-emitting element 21, the second inorganic light-emitting element 22, and the third inorganic light-emitting element 23 are formed, for example, by laminating a metal film, an insulating film, and a semiconductor film on a sapphire substrate.

[0106] In addition, Figure 6 In the illustration, the planar shapes of substrates SS1, SS2 and SS3 are shown as circles, but the planar shapes of substrates SS1, SS2 and SS3 are not limited to circles, and there are various variations such as quadrilaterals.

[0107] In this embodiment, an implementation where all substrates SS1, SS2, and SS3 are prepared in advance before the first holding substrate pushing process is described. However, as a variation, there are cases where all substrates SS1, SS2, and SS3 are not prepared in advance before the first holding substrate pushing process. For example, substrate SS2 may be prepared at least before the second holding substrate pushing process. Furthermore, substrate SS3 may be prepared at least before the third holding substrate pushing process.

[0108] In addition, during the array substrate preparation process, preparation Figure 7 The array substrate SUB1 is shown. Figure 7 It means in Figure 5 The diagram shows a schematic cross-sectional view of the array substrate SUB1 prepared during the array substrate preparation process. In the display area DA of the array substrate SUB1, a plurality of terminals 30 are arranged in a matrix. Figure 7 This represents a part of it.

[0109] like Figure 7 As shown, the array substrate SUB1 has a surface SUBt and a surface SUBb opposite to the surface SUBt. Surface SUBt is the surface to be mounted. Figure 6 The mounting surfaces of the plurality of LED elements 20 are shown. The array substrate SUB1 has a plurality of terminals 30. The plurality of terminals 30 include those intended to be connected to the first inorganic light-emitting element 21 (see reference). Figure 6 Terminal 31 (first terminal) for electrical connection. Multiple terminals 30 include those intended for connection to the second inorganic light-emitting element 22 (see reference). Figure 6 Terminal 32 (second terminal) for electrical connection. Furthermore, multiple terminals 30 include those intended for connection to the third inorganic light-emitting element 23 (see reference). Figure 6 Terminal 33 (third terminal) is electrically connected. Terminals 31, 32, and 33 are respectively connected to... Figure 1 The positions of the pixels shown are arranged in a matrix.

[0110] exist Figure 7 In the example shown, conductive contacts 40, which serve as protruding electrodes, are pre-formed on each of the plurality of terminals 30. However, as a variation, there are cases where the conductive contacts 40 are not pre-contacted with the terminals 30.

[0111] Figure 8 yes Figure 6 The figures shown are enlarged cross-sectional views of the various substrates. Since substrates SS1, SS2, and SS3 have the same cross-sectional structure, only one figure is shown to illustrate the common structure of substrates SS1, SS2, and SS3. Hereinafter, substrate SS1, which includes a plurality of first inorganic light-emitting elements 21, will be described as a representative example. However, in the following description, the first inorganic light-emitting element 21 can be replaced with a second inorganic light-emitting element 22 or a third inorganic light-emitting element 23, substrate SS1 can be replaced with substrate SS2 or substrate SS3, and element holding surface SS1t can be replaced with element holding surface SS2t or element holding surface SS3t.

[0112] exist Figure 8The plurality of first inorganic light-emitting elements 21 disposed on the element holding surface SS1t of the substrate SS1 shown respectively have an N-type semiconductor layer 24, an active layer 25 stacked on the N-type semiconductor layer 24, and a P-type semiconductor layer 26 stacked on the active layer 25. The N-type semiconductor layer 24 is formed as a common base layer for both the anode electrode 20EA and the cathode electrode 20EK, and the active layer 25 and the P-type semiconductor layer 26 are stacked on the anode electrode 20EA side. On the anode electrode 20EA side, a transparent electrode layer 27a is formed on the P-type semiconductor layer 26. The transparent electrode layer 27a on the anode electrode 20EA side and the N-type semiconductor layer 24 on the cathode electrode 20EK side are covered by a passivation film 28, which serves as an inorganic insulating film. Openings are formed in the passivation film 28 at the locations where the anode electrode 20EA and the cathode electrode 20EK are formed. At each opening, a metal electrode layer 27c is stacked with a seed layer 27b in between. The anode electrode 20EA is a stack of a transparent electrode layer 27a, a seed layer 27b, and a metal electrode layer 27c. On the other hand, the cathode electrode 20EK is a stack of a seed layer 27b and a metal electrode layer 27c stacked on an N-type semiconductor layer 24. A buffer layer 29 made of gallium nitride is formed between the N-type semiconductor layer 24 and the substrate SS1.

[0113] Furthermore, a light-shielding film LSF is formed between adjacent first inorganic light-emitting elements 21. The light-shielding film LSF is, for example, a laminated film composed of a seed layer 27b and a metal electrode layer 27c. For example, copper can be used as the seed layer 27b. Figure 6 As shown, the light-shielding film LSF, in a plan view, is a lattice-shaped metal film having multiple openings LSH arranged in a matrix. Furthermore, copper, aluminum, or gold can be used as the metal electrode layer 27c. The reasons for providing the light-shielding film LSF will be explained later.

[0114] <First Holding Substrate Pushing Process>

[0115] Next, regarding Figure 5 The first substrate pressing process shown will be explained. Figure 9 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state in which the holding substrate and the array substrate on which the first inorganic light-emitting element is arranged are pressed during the first holding substrate pressing process. Figure 10 It is Figure 9 The enlarged cross-sectional view shows the state of the connection interface between the LED element and the array substrate.

[0116] In the first substrate pressing process, with the substrate SS1 held by the worktable 61 facing the array substrate SUB1 held by the worktable 62, each of the plurality of first inorganic light-emitting elements 21 and the array substrate SUB1 are pressed together. In this process, as... Figure 10As shown, the terminal 31 of the array substrate SUB1 and the electrode 20E of the first inorganic light-emitting element 21 are electrically connected via a conductive bonding member 40. However, at this stage of the process, the conductive bonding member 40 is not bonded to the electrode 20E. The conductive bonding member 40 and the electrode 20E are bonded together in the subsequent laser irradiation process.

[0117] The worktable 61 is a component capable of holding the substrate SS1. The back surface SS1b of the substrate SS1 is held on the holding surface 61h of the worktable 61. The worktable 62 is a component capable of holding the array substrate SUB1. The surface SUBb of the array substrate SUB1 is held on the holding surface 62h of the worktable 62. Methods for holding the substrate SS1 by the worktable 61 and the array substrate SUB1 by the worktable 62 include, for example, a method of adsorption holding, or a method of fixing the periphery of the substrate SS1 or the array substrate SUB1 with a fixing clamp (not shown).

[0118] Figure 9 The holding surface 61h of the worktable 61 and the holding surface 62h of the worktable 62 shown are opposite to each other. Therefore, with the back surface SS1b of the substrate SS1 held on the holding surface 61h and the surface SUBb of the array substrate SUB1 held on the holding surface 62h, as shown... Figure 9 As shown, the element holding surface SS1t of substrate SS1 is opposite to the surface SUBt of array substrate SUB1. Furthermore, worktables 61 and 62 are each equipped with a mechanism capable of independently moving in a planar direction (X-Y plane). In this process, at least one of worktables 61 and 62 is moved in the X-Y plane for precise alignment, so that the electrodes 20E (refer to...) of the plurality of first inorganic light-emitting elements 21... Figure 10 ) respectively with terminals 31 of array substrate SUB1 (refer to Figure 10 ( ) Opposite. If the conductive connector 41 is pre-connected to the terminal 31, and alignment is performed along the X-Y plane, the conductive connector 41 connected to the terminal 31 will be in a state where it is opposite to the electrode 20E of the first inorganic light-emitting element 21. Alternatively, in Figure 10 If the electrode 20E shown has been pre-attached to the conductive connector 41, then if alignment is performed along the X-Y plane, the terminal 31 will be in a state where it is opposite to the conductive connector 41 attached to the electrode 20E of the first inorganic light-emitting element 21.

[0119] After the alignment along the X-Y plane described above, if the distance between worktable 61 and worktable 62 is brought closer, the plurality of first inorganic light-emitting elements 21 disposed on the element holding surface SS1t of substrate SS1 will approach array substrate SUB1 respectively. Figure 10As shown, when terminal 31 is in contact with conductive connector 41, or when electrode 20E is in contact with conductive connector 41, electrode 20E and terminal 31 of the first inorganic light-emitting element 21 are electrically connected via conductive connector 40. In this state, one of the interfaces between terminal 31 and conductive connector 41 and between electrode 20E and conductive connector 41 is not bonded but merely in contact.

[0120] Thus, the subsequent laser irradiation process is carried out while the bonding of either the interface between terminal 31 and conductive connector 41 or the interface between electrode 20E and conductive connector 41 is incomplete. As a result, an alloy layer is formed at the interface between conductive connector 41 and electrode 20E (or terminal 31) after being heated by laser energy. Electrode 20E and terminal 31 are then bonded via conductive connector 41.

[0121] In addition, Figure 9 The example shown illustrates an embodiment in which pushing force is applied by pushing the worktable 61 toward the worktable 62, but there are various variations in the method of applying the pushing force. For example, there are methods such as pushing the worktable 62 toward the worktable 61, or causing the worktable 61 and the worktable 62 to move in the Z direction respectively.

[0122] <Laser Irradiation Process>

[0123] Next, regarding Figure 5 The first laser irradiation process shown will be explained. Figure 11 It is a schematic representation of... Figure 5 An enlarged cross-sectional view showing the state of the conductive joint being heated by a laser during the first laser irradiation process. Figure 12 It means for Figure 11 An enlarged sectional view of the research example. Figure 11 and Figure 12 In the diagram, the range of the laser 51 traveling through the opening of the light-shielding film LSF is schematically represented by a shadow surrounded by double-dotted lines.

[0124] In the first laser irradiation process, after the first holding substrate pushing process, laser 51 is irradiated from the back side SS1b of substrate SS1 while substrate SS1 and array substrate SUB1 are being pushed, electrically connecting the first inorganic light-emitting element 21 to the terminal 31 of array substrate SUB1. Laser 51 is transparent to substrate SS1. In other words, substrate SS1 is transparent to laser 51.

[0125] In this process, when the laser 51 is irradiated onto the entire array substrate SUB1, it can sometimes cause damage to the components of the array substrate SUB1. Therefore, when irradiating the laser 51, a technique is needed to selectively irradiate it. Therefore, in this embodiment, by using... Figure 8 The light-shielding film LSF shown partially blocks the light from the laser 51, enabling selective irradiation of the laser 51.

[0126] In detail, the substrate SS1 has a light-shielding film LS1 formed on the element holding surface SS1t, which serves as the first element holding surface, and has light-shielding properties against the laser 51. Furthermore, as... Figure 6 As shown, in the plan view, a plurality of first inorganic light-emitting elements 21 are respectively arranged at positions overlapping with a plurality of openings LSH1 formed on the light-shielding film LS1. Figure 11 As shown, if laser 51 is irradiated from the back side SS1b of the substrate SS1 equipped with the light-shielding film LS1, the light will pass through the opening LSH1 (see reference). Figure 8 The laser 51 is selectively irradiated onto the first inorganic light-emitting element 21. The light irradiated onto the light-shielding film LSF is reflected or absorbed.

[0127] In addition, such as in Figure 12 As illustrated in the example, when a light-shielding film LSF is formed on the back side SS1b of the substrate SS1, light passing through the opening of the light-shielding film LSF is directed toward the array substrate SUB1, but diffraction occurs during its journey toward the element holding surface SS1t of the substrate SS1. Therefore, as... Figure 12 As shown, there is a case where the light described in the final description is irradiated onto the entire array substrate SUB1. Furthermore, in areas where light interferes with each other after passing through the openings, the light intensity increases. When stronger light is irradiated between adjacent LED elements 20, it can cause damage to the elements and circuits formed on the array substrate SUB1. Therefore, it is necessary to reduce the effect of light interference. One method to reduce the effect of light interference is to make the substrate SS1 very thin. However, by making the substrate SS1 thinner, the strength of the substrate SS1 decreases, thus reducing operability.

[0128] In this embodiment, such as Figure 11As shown, since the light-shielding film LS1 and a plurality of first inorganic light-emitting elements 21 are formed on the element holding surface SS1t of the substrate SS1, the laser 51 can be selectively irradiated onto the first inorganic light-emitting elements 21 with reduced light diffraction, regardless of the thickness of the substrate SS1. Thus, according to this embodiment, since the thickness of the substrate SS1 does not affect the diffraction of the laser 51, a substrate SS1 with sufficient thickness considering operability can be used. For example, in... Figure 11 In the example shown, the thickness of the substrate SS1 (the distance from one side of the element holding surface SS1t and the back surface SS1b to the other) is approximately 500–600 μm. The thickness of each of the plurality of first inorganic light-emitting elements 21 (…) Figure 11 The distance from the interface between the buffer layer 29 and the element holding surface SS1t to the front end of the anode electrode 20EA (as shown) is, for example, about 10 to 20 μm. Therefore, the thickness of the substrate SS1 is thicker than the thickness of each of the plurality of first inorganic light-emitting elements 21.

[0129] Furthermore, during the laser irradiation process, when laser 51 is irradiated, the distance from the component holding surface SS1t of the substrate SS1 to the back surface SS1b is more than 10 times the distance from the terminal 31 to the component holding surface SS1t. This allows the substrate SS1 to be sufficiently thick, thereby increasing its strength.

[0130] Through this process Figure 10 The electrode 20E of the first inorganic light-emitting element 21 and the terminal 31 of the array substrate SUB1 are respectively bonded to the conductive bonding member 41. In other words, the electrode 20E of the first inorganic light-emitting element 21 and the terminal 31 of the array substrate SUB1 are bonded to each other while being electrically connected via the conductive bonding member 41. In this process, damage to the components and circuits formed on the array substrate SUB1 due to laser irradiation can be avoided, and the electrode 20E and the terminal 31 can be electrically connected.

[0131] <First substrate peeling process>

[0132] Next, regarding Figure 5 The first substrate peeling process shown will be described. Figure 13 It is a schematic representation of... Figure 5 The diagram shows a cross-sectional view of the state after the holding substrate has been peeled from the plurality of first inorganic light-emitting elements during the first holding substrate peeling process. In the first holding substrate peeling process, as shown... Figure 13 As shown, after the first substrate pressing process, the substrate SS1 and the plurality of first inorganic light-emitting elements 21 are peeled off.

[0133] A method for separating the element holding surface SS1t of the substrate SS1, which serves as the holding substrate, from the close interface between the plurality of first inorganic light-emitting elements 21 can, for example, employ a technique called laser lift-off. When using the laser lift-off technique, an ultraviolet laser is irradiated, for example, from the back side SS1b of the substrate SS1 towards the close interface between the element holding surface SS1t of the substrate SS1 and the plurality of first inorganic light-emitting elements 21. Figure 8 As shown, a buffer layer 29 made of gallium nitride is formed between the N-type semiconductor layer 24 of the first inorganic light-emitting element 21 and the element holding surface SS1t of the substrate SS1. When a laser is irradiated onto the buffer layer 29, the surface layer of the buffer layer 29 (a portion of the element holding surface SS1t side) is modified, enabling the substrate SS1 and the first inorganic light-emitting element 21 to be peeled off.

[0134] This process yields a structure in which multiple first inorganic light-emitting elements 21 are mounted on an array substrate SUB1.

[0135] <Second Holding Substrate Pushing Process>

[0136] Next, regarding Figure 5 The second substrate pressing process shown will be explained. Figure 14 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state in which the substrate and the array substrate on which the second inorganic light-emitting element is arranged are pressed during the second substrate pressing process. Figure 15 It is Figure 14 An enlarged cross-sectional view showing the state of the connection interface between the second inorganic light-emitting element (LED) and the array substrate.

[0137] In the second substrate pressing process, with the substrate SS2 held by the worktable 61 facing the array substrate SUB1 held by the worktable 62, the plurality of second inorganic light-emitting elements 22 are pressed against the array substrate SUB1, and the plurality of terminals 32 of the array substrate SUB1 (refer to...) are pressed together. Figure 15 The array substrate SS2, held by the worktable 61, is electrically connected to multiple second inorganic light-emitting elements 22. In other words, during the second substrate pressing process, with the substrate SS2 held by the worktable 61 and the array substrate SUB1 held by the worktable 62 facing each other, the substrate SS2 and the array substrate SUB1 are pressed together, thereby connecting multiple terminals 32 of the array substrate SUB1 (refer to...) Figure 15 It is electrically connected to multiple second inorganic light-emitting elements 22.

[0138] The stage 61 is a component capable of holding the substrate SS2. The back surface SS2b of the substrate SS2 is held by the holding surface 61h of the stage 61. The stage 62 is a component capable of holding the array substrate SUB1. The surface SUBb of the array substrate SUB1 is held by the holding surface 62h of the stage 62. Various methods exist for the stage 61 to hold the substrate SS2 and for the stage 62 to hold the array substrate SUB1, as already described.

[0139] The holding surface 61h of the worktable 61 and the holding surface 62h of the worktable 62 face each other. Therefore, with the back surface SS2b of the substrate SS2 held by the holding surface 61h and the front surface SUBb of the array substrate SUB1 held by the holding surface 62h, as... Figure 14 As shown, the element holding surface SS2t of substrate SS2 is opposite to the surface SUBt of array substrate SUB1. Furthermore, worktables 61 and 62 are each equipped with a mechanism capable of independently moving in a planar direction (X-Y plane). In this process, at least one of worktables 61 and 62 is moved in the X-Y plane for precise alignment, so that the electrodes 20E (refer to...) of the plurality of second inorganic light-emitting elements 22... Figure 3 ) respectively with terminals 32 of array substrate SUB1 (refer to Figure 3 Opposite. In Figure 15 When the conductive connector 42 is pre-attached to the electrode 20E, if alignment is performed along the X-Y plane, the terminal 32 will be in a state where it faces the conductive connector 42 attached to the electrode 20E of the second inorganic light-emitting element 22. Alternatively, when the conductive connector 42 is pre-attached to the terminal 32, if alignment is performed along the X-Y plane, the conductive connector 42 attached to the terminal 32 will be in a state where it faces the electrode 20E of the second inorganic light-emitting element 22.

[0140] After the alignment along the X-Y plane described above, if the distance between worktable 61 and worktable 62 is brought closer, the plurality of second inorganic light-emitting elements 22 disposed on the element holding surface SS2t of substrate SS2 will approach the array substrate SUB1. Figure 15 As shown, when terminal 32 is in contact with conductive connector 42, or when electrode 20E is in contact with conductive connector 42, electrode 20E and terminal 32 of the second inorganic light-emitting element 22 are electrically connected via conductive connector 40. In this state, one of the interfaces between terminal 32 and conductive connector 42 and between electrode 20E and conductive connector 42 is not bonded; it is a state of only contact.

[0141] <Laser Irradiation Process>

[0142] Next, use Figure 11 right Figure 5 The second laser irradiation process will be described below. In the second laser irradiation process, after the second holding substrate pushing process, laser 51 is irradiated from the back side SS2b of substrate SS2 while substrate SS2 and array substrate SUB1 are being pushed together, electrically connecting the second inorganic light-emitting element 22 to the terminal 32 of array substrate SUB1. Laser 51 is transparent to substrate SS1. In other words, substrate SS1 is transparent to laser 51.

[0143] In the second laser irradiation process, after the second substrate pressing process, laser 51 is irradiated from the back side SS2b of substrate SS2 while substrate SS2 and array substrate SUB1 are pressed together, electrically connecting the second inorganic light-emitting element 22 to the terminal 32 of array substrate SUB1. Laser 51 can pass through substrate SS2. In other words, substrate SS2 is transmissive to laser 51. Preferably, in addition to suppressing laser 51 irradiation of components and circuits formed on array substrate SUB1, laser 51 irradiation of the first inorganic light-emitting element 21 already mounted on array substrate SUB1 is also suppressed. This is because the first inorganic light-emitting element 21 has been bonded to array substrate SUB1, and it is desirable to avoid the conductive bonding member 41 (see reference) at the bonding portion. Figure 10 It is reheated. In this embodiment, by using Figure 8 The light-shielding film LSF shown partially blocks the light from the laser 51, enabling selective irradiation of the laser 51.

[0144] In detail, the substrate SS2 has a light-shielding film LS2 formed on the element holding surface SS2t, which serves as the second element holding surface, and has light-shielding properties for the laser 51. Furthermore, as... Figure 6 As shown, in the plan view, a plurality of second inorganic light-emitting elements 22 are respectively arranged at positions overlapping with a plurality of openings LSH2 formed on the light-shielding film LS2. Figure 11 As shown, if laser 51 is irradiated from the back side SS2b of the substrate SS2 equipped with the light-shielding film LS2, the light will pass through the opening LSH2 (see reference). Figure 8 The laser 51 is selectively irradiated onto the second inorganic light-emitting element 22. The light irradiated onto the light-shielding film LSF is reflected or absorbed.

[0145] In addition, such as Figure 6 As shown, the light-shielding film LS2 completely covers the periphery of the opening LSH2 where the second inorganic light-emitting element 22 is disposed in the plan view. Therefore, in this process, as... Figure 14 As shown, at the time of this process, the multiple first inorganic light-emitting elements 21 already mounted on the array substrate SUB1 are respectively connected with... Figure 6The light-shielding film LS2 shown overlaps in the plan view. Therefore, according to this embodiment, in the second laser irradiation process, it is possible to prevent the laser 51 from irradiating the first inorganic light-emitting element 21.

[0146] In this embodiment, due to... Figure 11 As shown, the light-shielding film LS2 and a plurality of second inorganic light-emitting elements 22 are formed on the element holding surface SS2t of the substrate SS2. Therefore, regardless of the thickness of the substrate SS2, the laser 51 can be selectively irradiated onto the second inorganic light-emitting elements 22 with reduced light diffraction. Thus, according to this embodiment, the thickness of the substrate SS2 does not affect the diffraction of the laser 51, so a substrate SS2 with sufficient thickness considering operability can be used. For example, in Figure 11 In the example shown, the thickness of the substrate SS2 (the distance from one side of the element holding surface SS2t and the back surface SS2b to the other) is approximately 500–600 μm. The thickness of each of the plurality of second inorganic light-emitting elements 22 (…) Figure 11 The distance shown (from the interface between the buffer layer 29 and the element holding surface SS2t to the front end of the anode electrode 20EA) is, for example, about 10 to 20 μm. Therefore, the thickness of the substrate SS2 is thicker than the thickness of each of the plurality of second inorganic light-emitting elements 22.

[0147] Furthermore, during the laser irradiation process, when laser 51 is irradiated, the distance from the component holding surface SS2t of the substrate SS2 to the back surface SS2b is more than 10 times the distance from the terminal 32 to the component holding surface SS2t. This allows the thickness of the substrate SS2 to be sufficiently increased, thus improving the strength of the substrate SS2.

[0148] Through this process Figure 15 The electrodes 20E of the second inorganic light-emitting element 22 and the terminals 32 of the array substrate SUB1 are respectively bonded to the conductive bonding member 42. In other words, the electrodes 20E of the second inorganic light-emitting element 22 and the terminals 32 of the array substrate SUB1 are bonded to each other in a state of electrical connection via the conductive bonding member 42.

[0149] <Second step of substrate peeling>

[0150] Next, regarding Figure 5 The second substrate peeling process shown will be explained. Figure 16 It is a schematic representation of... Figure 5 The diagram shows a cross-sectional view of the second holding substrate peeling process, in which the holding substrate has been peeled from the plurality of second inorganic light-emitting elements. In the second holding substrate peeling process, as shown... Figure 16As shown, after the second laser irradiation process, the substrate SS2 and the plurality of second inorganic light-emitting elements 22 are peeled off. The method for peeling off the close-fitting interface between the element holding surface SS2t of the substrate SS2 (which serves as the holding substrate) and the plurality of second inorganic light-emitting elements 22 is the same as the first holding substrate peeling process described above; for example, a technique called laser peeling can be used. Through this process, a structure in which a plurality of first inorganic light-emitting elements 21 and a plurality of second inorganic light-emitting elements 22 are mounted on the array substrate SUB1 can be obtained.

[0151] <Third step of holding substrate push-up>

[0152] Next, regarding Figure 5 The third substrate pressing process shown will be explained. Figure 17 It is a schematic representation of... Figure 5 The cross-sectional view shown is of the state in which the substrate and the array substrate on which the third inorganic light-emitting element is arranged are pressed during the third substrate pressing process. Figure 18 It is Figure 17 An enlarged cross-sectional view showing the state of the connection interface between the third inorganic light-emitting element (LED) and the array substrate.

[0153] In the third substrate pressing process, with the substrate SS3 held by the worktable 61 and the array substrate SUB1 held by the worktable 62 facing each other, the plurality of third inorganic light-emitting elements 23 are pressed against the array substrate SUB1, and the plurality of terminals 33 of the array substrate SUB1 (refer to...) are pressed together. Figure 18 The array substrate SS3 is electrically connected to multiple third inorganic light-emitting elements 23. In other words, in the third holding substrate pushing process, the substrate SS3 held by the worktable 61 and the array substrate SUB1 held by the worktable 62 are pressed together, thereby pushing the multiple terminals 33 of the array substrate SUB1 (refer to...) Figure 18 It is electrically connected to multiple third inorganic light-emitting elements 23.

[0154] The stage 61 is a component capable of holding the substrate SS3. The back surface SS3b of the substrate SS3 is held by the holding surface 61h of the stage 61. The stage 62 is a component capable of holding the array substrate SUB1. The surface SUBb of the array substrate SUB1 is held by the holding surface 62h of the stage 62. Various methods exist for the stage 61 to hold the substrate SS3 and for the stage 62 to hold the array substrate SUB1, as already described.

[0155] The holding surface 61h of the worktable 61 and the holding surface 62h of the worktable 62 face each other. Therefore, with the back surface SS3b of the substrate SS3 held by the holding surface 61h and the front surface SUBb of the array substrate SUB1 held by the holding surface 62h, as... Figure 17 As shown, the element holding surface SS3t of substrate SS3 is opposite to the surface SUBt of array substrate SUB1. Furthermore, worktables 61 and 62 are each equipped with a mechanism capable of independently moving in a planar direction (X-Y plane). In this process, at least one of worktables 61 and 62 is moved in the X-Y plane for precise alignment, so that the electrodes 20E (refer to...) of the plurality of third inorganic light-emitting elements 23... Figure 3 ) respectively with terminals 33 of array substrate SUB1 (refer to Figure 3 Opposite. In Figure 18 When the conductive connector 43 is pre-attached to the electrode 20E, if alignment is performed along the X-Y plane, the terminal 33 will be in a state where it faces the conductive connector 43 attached to the electrode 20E of the third inorganic light-emitting element 23. Alternatively, when the conductive connector 43 is pre-attached to the terminal 33, if alignment is performed along the X-Y plane, the conductive connector 43 attached to the terminal 33 will be in a state where it faces the electrode 20E of the third inorganic light-emitting element 23.

[0156] If, after the alignment along the X-Y plane described above, the distance between worktable 61 and worktable 62 is brought close, then the plurality of third inorganic light-emitting elements 23 disposed on the element holding surface SS3t of substrate SS3 will approach array substrate SUB1 respectively. Figure 18 As shown, when terminal 33 is in contact with conductive connector 43, or when electrode 20E is in contact with conductive connector 43, electrode 20E of the third inorganic light-emitting element 23 is electrically connected to terminal 33 via conductive connector 40. In this state, one of the interfaces between terminal 33 and conductive connector 43 and the interface between electrode 20E and conductive connector 43 is not bonded, but merely in contact.

[0157] <Laser Irradiation Process>

[0158] Next, use Figure 11 right Figure 5 The third laser irradiation process will be described below. In the third laser irradiation process, after the third holding substrate pushing process, laser 51 is irradiated from the back side SS3b of substrate SS3 while substrate SS3 and array substrate SUB1 are being pushed together, electrically connecting the third inorganic light-emitting element 23 to the terminal 33 of array substrate SUB1. Laser 51 is transparent to substrate SS1. In other words, substrate SS1 is transparent to laser 51.

[0159] In the third laser irradiation process, it is preferable to suppress not only the irradiation of the laser 51 onto the components and circuits formed on the array substrate SUB1, but also the irradiation of the laser 51 onto the first inorganic light-emitting element 21 and the second inorganic light-emitting element 22 already mounted on the array substrate SUB1. This is because the first inorganic light-emitting element 21 and the second inorganic light-emitting element 22 have already been bonded to the array substrate SUB1, and it is desirable to prevent the conductive bonding member 41 (see reference) at the bonding portion from being exposed. Figure 10 ) and conductive connector 42 (refer to) Figure 15 It is reheated. In this embodiment, by using Figure 8 The light-shielding film LSF shown partially blocks the light from the laser 51, enabling selective irradiation of the laser 51.

[0160] In detail, the substrate SS3 has a light-shielding film LS3 formed on the element holding surface SS3t, which serves as the third element holding surface, and has light-shielding properties for the laser 51. Furthermore, as... Figure 6 As shown, in the plan view, multiple third inorganic light-emitting elements 23 are respectively arranged at positions overlapping with multiple openings LSH3 formed on the light-shielding film LS3. Figure 11 As shown, if laser 51 is irradiated from the back side SS3b of the substrate SS3 equipped with the light-shielding film LS3, the laser light will pass through the opening LSH3 (see reference). Figure 8 The laser 51 is then selectively irradiated onto the third inorganic light-emitting element 23. The light irradiated onto the light-shielding film LSF is either reflected or absorbed.

[0161] In addition, such as Figure 6 As shown, the light-shielding film LS3 completely covers the periphery of the opening LSH3 where the third inorganic light-emitting element 23 is disposed in the plan view. Therefore, in this process, as... Figure 14 As shown, at the time point of this process, the multiple first inorganic light-emitting elements 21 and second inorganic light-emitting elements 22 already mounted on the array substrate SUB1 are respectively connected with... Figure 6 The light-shielding film LS3 shown overlaps in the plan view. Therefore, according to this embodiment, in the third laser irradiation process, it is possible to prevent the laser 51 from being irradiated onto the first inorganic light-emitting element 21 and the second inorganic light-emitting element 22.

[0162] In this embodiment, due to... Figure 11As shown, the light-shielding film LS3 and a plurality of third inorganic light-emitting elements 23 are formed on the element holding surface SS3t of the substrate SS3. Therefore, regardless of the thickness of the substrate SS3, the laser 51 can be selectively irradiated onto the third inorganic light-emitting elements 23 with reduced light diffraction. Thus, according to this embodiment, since the thickness of the substrate SS3 does not affect the diffraction of the laser 51, a substrate SS3 with sufficient thickness considering operability can be used. For example, in Figure 11 In the example shown, the thickness of the substrate SS3 (the distance from one side of the element holding surface SS3t and the back surface SS3b to the other) is approximately 500–600 μm. The thickness of each of the plurality of third inorganic light-emitting elements 23 (…) Figure 11 The distance shown (from the interface between the buffer layer 29 and the element holding surface SS3t to the front end of the anode electrode 20EA) is, for example, about 10 to 20 μm. Therefore, the thickness of the substrate SS3 is thicker than the thickness of each of the plurality of third inorganic light-emitting elements 23.

[0163] Furthermore, during the laser irradiation process, when laser 51 is irradiated, the distance from the component holding surface SS3t of the substrate SS3 to the back surface SS3b is more than 10 times the distance from the terminal 33 to the component holding surface SS3t. This allows the substrate SS3 to be sufficiently thick, thus increasing its strength.

[0164] Through this process Figure 15 The electrode 20E of the third inorganic light-emitting element 23 and the terminal 33 of the array substrate SUB1 are respectively bonded to the conductive bonding member 43. In other words, the electrode 20E of the third inorganic light-emitting element 23 and the terminal 33 of the array substrate SUB1 are bonded to each other in a state of electrical connection via the conductive bonding member 43.

[0165] <Third step: substrate peeling process>

[0166] Next, regarding Figure 5 The third substrate removal process will be described below. Although not shown in the diagram, this third substrate removal process occurs after the third laser irradiation process. Figure 17 The substrate SS3 and the plurality of third inorganic light-emitting elements 23 are peeled off. The method for peeling off the close interface between the element holding surface SS3t of the substrate SS3, which serves as the holding substrate, and the plurality of third inorganic light-emitting elements 23 is the same as the first holding substrate peeling process described above, and for example, a technique called laser peeling can be used. Through this process, a structure in which a plurality of first inorganic light-emitting elements 21 and a plurality of third inorganic light-emitting elements 23 are mounted on the array substrate SUB1 can be obtained.

[0167] As explained above, according to this embodiment, when using Figure 10, Figure 15 and Figure 18 In the laser irradiation process of the conductive bonding member 40 shown being bonded to a terminal 30 and an electrode 20E, damage to the components, circuits formed on the array substrate SUB1 or the already mounted LED components 20 can be prevented by selectively irradiating the laser.

[0168] In addition, Figure 5 The example shown illustrates an embodiment where three types of LED components are installed sequentially; however, the types of LED components installed are not limited to three. For example, if only one type of LED component is installed, it is possible to... Figure 5 The second holding substrate pushing process to the third holding substrate peeling process shown is omitted. Furthermore, in the case of a manufacturing method for a display device that mounts two types of LED elements, it is possible to... Figure 5 The steps from the third holding substrate pushing process to the third holding substrate peeling process are omitted. Furthermore, in the manufacturing method of a display device that mounts four or more types of LED elements, it is possible to... Figure 5 The holding substrate is obtained by repeating the holding substrate pushing process and the holding substrate peeling process after the third holding substrate peeling process, which are different types of LED elements from the first to the third types of LED elements.

[0169] <Example of substrate deformation>

[0170] right Figure 6 and Figure 8 The following describes a deformation example of the substrate. Figure 19 It means relative to Figure 8 An enlarged cross-sectional view of a modified example of the substrate shown. Figure 20 It means that it is in use Figure 19 In the manufacturing method of the display device that holds the substrate shown, relative to Figure 11 An enlarged sectional view of a modified example. Figure 6 and Figure 8 The substrates SS1, SS2, and SS3 shown are holding substrates used when LED elements 20 are formed on a sapphire substrate and then formed onto an array substrate SUB1. On the other hand, as a variation of the above, there is a manufacturing method in which the LED elements 20 formed on the sapphire substrate are transferred to a holding substrate other than the sapphire substrate and then mounted onto the array substrate SUB1. Hereinafter, the holding substrate used in this variation will be described. Furthermore, the manufacturing method of the display device using the holding substrate described below can be compared with... Figure 5 The process shown is the same as the process shown, or it may be omitted. Figure 5 The process is carried out after the second substrate pushing process shown.

[0171] In this variant example, Figure 5 The LED holding substrate preparation process shown includes a process of transferring a plurality of LED elements 20 formed on a sapphire substrate to a transfer substrate (not shown), and a process of transferring the plurality of LED elements 20 transferred to the transfer substrate to... Figure 19 The process shown is the re-transfer of the substrate via SSH. Figure 19 The holding substrate SSH shown is the holding substrate after the transfer. Figure 5 The first, second, and third holding substrate pushing processes shown use respectively... Figure 19 The holding substrate SSH is shown. In the process of transferring to a transfer substrate (not shown), the LED element 20 is peeled off from the sapphire substrate using laser lift-off. At this time, there are... Figure 19 The buffer layer 29 shown is not left. Therefore, in Figure 19 In the process of holding the LED element 20 with the holding substrate SSH shown, there are Figure 19 The case where the buffer layer 29 is absent, or where it exists as a part of the buffer layer 29.

[0172] Figure 19 The holding substrate SSH shown is similar to having the component holding member 70 in this respect. Figure 8 The substrate SS1 shown is different. The holding substrate SSH has a component holding surface (component holding member forming surface) SSHt and a back surface SSHb opposite to the component holding surface SSHt. The component holding member 70 is fixed to the component holding surface SSHt of the holding substrate SSH. The component holding member 70 has a plurality of protrusions 71 made of an elastomer and protruding in a direction away from the component holding surface SSHt. The plurality of protrusions 71 are respectively disposed in a plurality of openings LSH provided in the light-shielding film LSF. A plurality of LED elements 20 are respectively attached to the front end surfaces of the plurality of protrusions 71 of the component holding member 70. In detail, an adhesive layer 72 is disposed on the front end surface of the protrusion 71, and the surface 20b of the LED element 20 is attached to the adhesive layer 72.

[0173] Regarding the method of attaching the LED element 20 to the front end face of the protrusion 71 of the element holding member 70, for example, it can be applied to... Figure 8 The method shown describes the sequential mounting of a first inorganic light-emitting element 21, a second inorganic light-emitting element 22, and a third inorganic light-emitting element 23 on an array substrate SUB1. When the LED element 20 is attached and fixed to the holding substrate SSH, the laser irradiation process can be omitted since electrical connections are not required.

[0174] Using the retaining substrate SSH in this modified example Figure 5In the case of the laser irradiation process shown, for example, Figure 20 As shown, with the holding substrate SSH and the array substrate SUB1 pressed together, laser 51 is irradiated from the back side SSHb of the holding substrate SSH, electrically connecting the LED element 20 to the terminal 31 of the array substrate SUB1. Laser 51 is permeable to the holding substrate SSH and the element holding member 70. In other words, the holding substrate SSH and the element holding member 70 are permeable to laser 51.

[0175] The substrate SSH has a light-shielding film LSF formed on the component holding surface SSHt, which provides light shielding against laser 51. Furthermore, as... Figure 6 As shown, in a plan view, multiple LED elements 20 are respectively arranged at positions overlapping with multiple openings LSH formed in the light-shielding film LSF. Figure 11 As shown, if laser 51 is irradiated from the back side SSHb of the holding substrate SSH with the light-shielding film LSF, the laser light passes through the opening LSH (see reference). Figure 19 The laser 51 is then selectively irradiated onto the LED element 20. The light irradiated onto the light-shielding film LSF is either reflected or absorbed.

[0176] Furthermore, the light-shielding film LSF completely covers the periphery of the opening LSH of the LED element 20 in a plan view. Therefore, in this process, it is possible to suppress the laser 51 from irradiating the periphery of the LED element 20. For example, when using a holding substrate SSH, and... Figure 5 When the process involves mounting the first, second, and third inorganic light-emitting elements, it is possible to prevent the laser 51 from irradiating the previously mounted LED element 20. Furthermore, for example, when multiple types of LED elements 20 are mounted together using a retaining substrate SSH, it is possible to suppress the irradiation of the laser 51 into the area between adjacent LED elements 20.

[0177] Furthermore, in this modified example, due to... Figure 20 As shown, the light-shielding film LSF and multiple LED elements 20 are disposed on the element holding surface SSHt of the holding substrate SSH. Therefore, regardless of the thickness of the holding substrate SSH, the laser 51 can be selectively irradiated onto the LED elements 20 with reduced light diffraction. Thus, according to this embodiment, since the thickness of the holding substrate SSH does not affect the diffraction of the laser 51, a holding substrate SSH with sufficient thickness considering operability can be used. For example, in Figure 11 In the example shown, the thickness of the substrate SSH (the distance from one side of the component holding surface SSHt and the back surface SS2b to the other) is approximately 500–600 μm. The thickness of each of the multiple LED components 20 (…) Figure 11The distance from the interface between the element holding surface SSHt and the front end of the anode electrode 20EA is, for example, about 10 to 20 μm. Therefore, the thickness of the holding substrate SSH is thicker than the thickness of each of the multiple LED elements 20.

[0178] Furthermore, the thickness of the protrusion 71 of the component holding member 70 (i.e., the thickness of the thickest part of the component holding member 70) is approximately 10 to 20 μm. Therefore, during the laser irradiation process, when the laser 51 is irradiated, the distance from the component holding surface SSHt of the holding substrate SSH to the back surface SS2b is more than 10 times the distance from the terminal 32 to the component holding surface SSHt. This allows the holding substrate SSH to be sufficiently thick, thus increasing its strength.

[0179] In this modified example, multiple types of LED elements 20 can be mounted onto the array substrate SUB1 simultaneously. In this case, the time required for the substrate pressing process can be reduced compared to... Figure 5 The example shown is shortened.

[0180] The embodiments and representative modifications have been described above, but the above-described techniques can be applied to various modifications other than those illustrated. For example, the above-described modifications can also be combined with each other.

[0181] Within the scope of the present invention, those skilled in the art will be able to conceive of various modifications and alterations, and it should be understood that these modifications and alterations also fall within the scope of the present invention. For example, any appropriate additions, deletions, or design changes to the constituent elements of the above embodiments, or any additions, omissions, or changes to the steps or conditions, are also included within the scope of the present invention as long as they possess the spirit of the present invention.

[0182] Industrial availability

[0183] This invention can be used in display devices and electronic devices assembled with display devices.

Claims

1. A method for manufacturing a display device, characterized in that, include: (a) A process of preparing a first substrate and an array substrate having a plurality of first terminals and pixel circuits connected to the first terminals, wherein the first substrate has a first element holding surface and a first back surface opposite to the first element holding surface, and a plurality of first inorganic light-emitting elements are arranged in a matrix on the first element holding surface. (b) A process of pressing the first substrate and the array substrate while the first element holding surface of the first substrate held by the first worktable is facing the array substrate held by the second worktable; and (c) After the above (b) process, with the first substrate and the array substrate pressed, a laser is irradiated from the first back side of the first substrate to electrically connect the plurality of first inorganic light-emitting elements to the plurality of first terminals of the array substrate. The aforementioned laser can pass through the aforementioned first substrate; The first substrate has a first light-shielding film formed on the holding surface of the first element and having light-shielding properties against the laser. In a plan view, the plurality of first inorganic light-emitting elements are respectively disposed at positions overlapping with the plurality of first openings formed in the first light-shielding film.

2. The method for manufacturing a display device as claimed in claim 1, characterized in that, The array substrate prepared by the above-mentioned process (a) also has a plurality of second terminals formed thereon; The method for manufacturing the above-mentioned display device includes: (d) A process of peeling off the first substrate and the plurality of first inorganic light-emitting elements after the process (c) above; (e) The process of preparing a second substrate, wherein the second substrate has a second element holding surface and a second back surface opposite to the second element holding surface, and a plurality of second inorganic light-emitting elements are arranged in a matrix on the second element holding surface. (f) A step of pressing the second substrate and the array substrate after steps (d) and (e) above, with the second element holding surface of the second substrate held by the first worktable facing the array substrate held by the second worktable; and (g) After the above (f) process, with the second substrate and the array substrate pressed down, the laser is irradiated from the second back side of the second substrate and the plurality of second inorganic light-emitting elements are electrically connected to the plurality of second terminals of the array substrate. The aforementioned laser can pass through the aforementioned second substrate; The second substrate has a second light-shielding film formed on the second element holding surface and having light-shielding properties against the laser. In a plan view, the plurality of second inorganic light-emitting elements are respectively arranged at positions overlapping with the plurality of second openings formed in the second light-shielding film.

3. The method for manufacturing a display device as described in claim 2, characterized in that, The array substrate prepared by the above-mentioned process (a) also has a plurality of third terminals formed thereon; The method for manufacturing the above-mentioned display device includes: (h) A process of peeling off the second substrate and the plurality of second inorganic light-emitting elements after the process described in (g); (i) The process of preparing a third substrate, wherein the third substrate has a third element holding surface and a third back surface opposite to the third element holding surface, and a plurality of third inorganic light-emitting elements are arranged in a matrix on the third element holding surface. (k) A step of pressing the third substrate and the array substrate after steps (h) and (i) above, with the third element holding surface of the third substrate held by the first worktable facing the array substrate held by the second worktable; and (m) After the above (k) process, the laser is irradiated from the third back side of the third substrate while the third substrate and the array substrate are pressed, and the plurality of third inorganic light-emitting elements are electrically connected to the plurality of third terminals of the array substrate. The aforementioned laser can pass through the aforementioned third substrate; The third substrate has a third light-shielding film formed on the holding surface of the third element and having light-shielding properties against the laser. In a plan view, the plurality of third inorganic light-emitting elements are respectively disposed at positions overlapping with the plurality of third openings formed in the third light-shielding film.

4. The method for manufacturing a display device as claimed in claim 1, characterized in that, The thickness of the first substrate is greater than the thickness of each of the plurality of first inorganic light-emitting elements.

5. The method for manufacturing a display device as claimed in claim 1, characterized in that, When the laser is irradiated in step (c) above, The distance from the first element holding surface of the first substrate to the first back surface is more than 10 times the distance from the first terminal to the first element holding surface.

6. The method for manufacturing a display device as claimed in claim 1, characterized in that, An element holding member is fixed on the first element holding surface of the first substrate. The element holding member is made of an elastomer and has a plurality of protrusions that protrude in a direction away from the first element holding surface. The aforementioned protruding parts are respectively disposed in the aforementioned multiple first openings; The aforementioned plurality of first inorganic light-emitting elements are respectively attached to the front end face of the aforementioned plurality of protrusions of the aforementioned element holding member.

7. An inorganic light-emitting element holding substrate, used to temporarily hold inorganic light-emitting elements and manufacture a display device by transferring the inorganic light-emitting elements to an array substrate, characterized in that, have: The substrate has a first element holding surface and a first back surface opposite to the first element holding surface; A light-shielding film is formed on the holding surface of the first element; and Multiple inorganic light-emitting elements are held on the surface of the first element mentioned above; The aforementioned substrate has light transmittance; The aforementioned inorganic light-emitting elements are respectively disposed in the aforementioned openings formed in the aforementioned light-shielding film.

8. The inorganic light-emitting element holding substrate as described in claim 7, characterized in that, The thickness of the substrate is greater than the thickness of each of the aforementioned inorganic light-emitting elements.

9. The inorganic light-emitting element holding substrate as described in claim 7, characterized in that, An element holding member is fixed on the first element holding surface of the substrate. The element holding member is made of an elastomer and has a plurality of protrusions that protrude in a direction away from the first element holding surface. The aforementioned protruding parts are respectively disposed in the aforementioned openings; The aforementioned inorganic light-emitting elements are respectively attached to the front end face of the aforementioned protrusions of the aforementioned element holding component.

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