JP2023023684A - Method of manufacturing display device - Google Patents

Abstract

To improve performance of a display device.SOLUTION: A manufacturing method of a display device includes the following steps: a step (a) of preparing a first substrate on which a plurality of first inorganic light emitting elements are arranged in matrix and an array substrate on which a plurality of first terminals are formed; a step (b) of measuring thickness of the first substrate, thickness of one or more first inorganic light emitting elements, and thickness of the array substrate; a step (c) of electrically connecting the first terminals on the array substrate to the first inorganic light emitting elements by pressing each of the first inorganic elements and the array substrate while the first substrate held by a first stage faces the array substrate held by a second stage; and a step (d) of separating the first substrate and the first inorganic light emitting elements. In the step (c), the amount of pressing the array substrate and each of the first inorganic light emitting elements is controlled on the basis of results measured in the step (b).SELECTED DRAWING: Figure 5

Description

The present invention relates to manufacturing technology for display devices.

As a display device, there is an LED (Light Emitting Diode) display device in which inorganic light emitting diode elements, which are self-luminous elements, are arranged in a matrix on a substrate (see, for example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2020-67626). ). Further, as a display device with higher definition, there is a micro LED display device using minute inorganic light emitting diode elements called micro LED (see, for example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2019-36719)).

Japanese Patent Application Laid-Open No. 2020-67626 JP 2019-36719 A

A manufacturing process of an LED display device and a manufacturing process of a micro LED display device include a process of mounting a plurality of LED elements (or micro LED elements) on a substrate. In the process of mounting the plurality of LED elements, the plurality of LED elements are pressed against the substrate. At this time, it is important to control the pressure (pressing force) that presses the plurality of LED elements against the substrate. For example, if the pressing force is excessive, it may damage a plurality of LED elements or substrates. Further, if the pressing force is too small, it may cause deterioration in reliability of electrical connection between the terminal formed on the substrate and the LED element.

An object of the present invention is to provide a technique for improving the performance of a display device using a plurality of inorganic light emitting diode elements.

A method for manufacturing a display device, which is one embodiment of the present invention, includes the following steps. (a) A step of preparing a first substrate on which a plurality of first inorganic light emitting elements are arranged in a matrix and an array substrate on which a plurality of first terminals are formed. (b) measuring the thickness of the first substrate, the thickness of one or more first inorganic light emitting elements among the plurality of first inorganic light emitting elements, and the thickness of the array substrate; (c) with the first substrate held on the first stage and the array substrate held on the second stage facing each other, each of the plurality of first inorganic light emitting elements and the array substrate are separated; A step of electrically connecting the plurality of first terminals of the array substrate and the plurality of first inorganic light emitting elements by pressing. (d) a step of separating the first substrate and the plurality of first inorganic light emitting elements after the step (c); In the step (c), the strength with which each of the plurality of first inorganic light emitting devices is pressed against the array substrate is controlled based on the result of the measurement in the step (b).

1 is a plan view showing a configuration example of a display device according to an embodiment; FIG. 2 is a circuit diagram showing a configuration example of a circuit around a pixel shown in FIG. 1; FIG. 2 is an enlarged cross-sectional view showing an example of a peripheral structure of an LED element arranged in each of a plurality of pixels of the display device shown in FIG. 1; FIG. FIG. 4 is an enlarged sectional view showing a modified example of the LED element shown in FIG. 3; FIG. 2 is an explanatory diagram showing a flow of a manufacturing process of the display device shown in FIG. 1; 6 is a plan view showing an outline of a substrate prepared in the LED holding substrate preparation step shown in FIG. 5; FIG. 6 is a cross-sectional view showing an outline of an array substrate SUB1 prepared in the array substrate preparation step shown in FIG. 5; FIG. FIG. 6 is a cross-sectional view schematically showing an example of a measurement point in the thickness measurement process shown in FIG. 5; 6 is an explanatory diagram showing an example of a thickness measuring method in the thickness measuring step shown in FIG. 5; FIG. 6 is a cross-sectional view schematically showing a state in which the substrate on which the first inorganic light emitting elements are arranged and the array substrate are pressed together in the step of mounting the first LED elements shown in FIG. 5; FIG. 6 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of first inorganic light emitting elements in the first holding substrate peeling step shown in FIG. 5; FIG. FIG. 6 is a cross-sectional view schematically showing a state in which the substrate on which the second inorganic light emitting elements are arranged and the array substrate are pressed together in the second LED element mounting step shown in FIG. 5 ; 6 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of second inorganic light emitting elements in the second holding substrate peeling step shown in FIG. 5; FIG. 6 is a cross-sectional view schematically showing a state in which the substrate on which the third inorganic light emitting elements are arranged and the array substrate are pressed together in the third LED element mounting step shown in FIG. 5; FIG. 6 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of third inorganic light emitting elements in the third holding substrate peeling step shown in FIG. 5; FIG. FIG. 11 is a cross-sectional view schematically showing a modification to FIG. 10 and showing a state before mounting on an array substrate using a holding substrate collectively holding a plurality of types of LED elements.

Each embodiment of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art will naturally include within the scope of the present invention any appropriate modifications that can be easily conceived while maintaining the gist of the invention. In addition, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual embodiment, but this is only an example, and the interpretation of the present invention is not intended. It is not limited. In addition, in this specification and each figure, the same or related reference numerals may be given to elements similar to those described above with respect to the previous figures, and detailed description thereof may be omitted as appropriate.

In the following embodiments, a micro LED display device including a plurality of micro LED elements will be described as an example of a display device using a plurality of inorganic light emitting elements. Micro LED elements are smaller in size (outer diameter) than general LED elements, and therefore have the advantage of being able to display high-definition images. However, since the micro LED element is small in size, the pressing force margin to be controlled is small in the process of mounting the light emitting diode element, which will be described later.

As a light-emitting diode element that is a self-luminous element, there is an organic light-emitting diode element (OLED: Organic Light-Emitting Diode). Inorganic light emitting diode elements (micro LED elements) described in the following embodiments are distinguished from organic light emitting diode elements.

<Display device>
First, a configuration example of a micro LED display device, which is the display device of this embodiment, will be described. FIG. 1 is a plan view showing a configuration example of a display device according to one embodiment. In FIG. 1, the boundary between the display area DA and the peripheral area PFA, the control circuit 5, the drive circuit 6, and the plurality of pixels PIX are indicated by two-dot chain lines. FIG. 2 is a circuit diagram showing a configuration example of a circuit around the pixel shown in FIG.

As shown in FIG. 1, the display device DSP1 of the present embodiment includes a display area DA, a peripheral area PFA located around the display area DA, and a plurality of pixels PIX arranged in a matrix within the display area DA. and have The display device DSP1 also has a substrate 10, a control circuit 5 formed on the substrate 10, and a drive circuit 6 formed on the substrate 10. FIG.

The control circuit 5 is a control circuit that controls driving of the display function of the display device DSP1. For example, the control circuit 5 is a driver IC (Integrated Circuit) mounted on the substrate 10 . In the example shown in FIG. 1, the control circuit 5 is arranged along one of the four sides of the substrate 10 along one short side. In addition, in the example of the present embodiment, the control circuit 5 includes a signal line driving circuit that drives the video signal lines VL (see FIG. 2) connected to the plurality of pixels PIX. However, the position and configuration example of the control circuit 5 are not limited to the example shown in FIG. 1, and there are various modifications. For example, in FIG. 1, a circuit board such as a flexible board may be connected to the position shown as the control circuit 5, and the driver IC described above may be mounted on the circuit board. Further, for example, a signal line driving circuit that drives the video signal lines VL may be formed separately from the control circuit 5 .

The drive circuit 6 is a circuit that drives the scanning signal line GL among the plurality of pixels PIX. The drive circuit 6 drives the scanning signal lines GL based on the control signal from the control circuit 5 . In the example shown in FIG. 1 , the drive circuit 6 is arranged along each of two long sides of the four sides of the substrate 10 . However, the position and configuration example of the drive circuit 6 are not limited to the example shown in FIG. 1, and there are various modifications. For example, in FIG. 1, a circuit board such as a flexible board may be connected to the position shown as the control circuit 5, and the drive circuit 6 described above may be mounted on the circuit board.

Next, a circuit configuration example of the pixel PIX will be described with reference to FIG. In FIG. 2, one pixel PIX is shown as a representative, but each of the plurality of pixels PIX shown in FIG. 1 has a circuit similar to that of the pixel PIX shown in FIG. Hereinafter, the circuit including the switch, capacitor, and LED element 20 included in the pixel PIX may be referred to as a pixel circuit. The pixel circuit is a voltage signal type circuit that controls the light emitting state of the LED element 20 according to the video signal Vsg supplied from the control circuit 5 (see FIG. 1).

As shown in FIG. 2, the pixel PIX has an LED element 20 . The LED element 20 is the micro light emitting diode described above. The LED element 20 has an anode electrode 20EA (see FIG. 3 described later) and a cathode electrode EK (see FIG. 3 described later). Each of the anode electrode 20EA and the cathode electrode 20EK of the LED element 20 is electrically connected to the terminal 30 of the pixel PIX. In the example shown in FIG. 2, the cathode electrode 20EK of the LED element 20 is connected to the terminal 30L, and the anode electrode 20EA of the LED element 20 is connected to the terminal 30H. A potential PVS that is a relatively low fixed potential (low potential) is supplied to the terminal 30L, and a potential PVD that is a fixed potential (high potential) higher than the potential supplied to the terminal 30L is supplied to the terminal 30H. be.

The pixel PIX has an output switch BCT, a drive transistor DRT, and a pixel switch SST. The output switch BCT is a transistor that controls the light emission time of the LED element 20 in response to the control signal Gsb supplied from the drive circuit 6. FIG. The drive transistor DRT is a transistor that controls the amount of drive current supplied to the anode electrode of the LED element 20 according to the video signal Vsg. The pixel switch SST is a transistor that controls the connection state (on or off state) between the pixel circuit and the video signal line VL in response to the control signal Gss. The drive circuit 6 also includes a reset switch RST that controls input of a reset potential. Each of the output switch BCT, drive transistor DRT, pixel switch SST, and reset switch RST is a thin film transistor, for example. When the pixel switch SST is on, the pixel circuit receives the video signal Vsg from the video signal line VL.

The drive circuit 6 includes a shift register circuit, an output buffer circuit and the like (not shown). Drive circuit 6 outputs a pulse based on a horizontal scanning start pulse transmitted from control circuit 5 (see FIG. 1), and outputs control signal Gss, control signal Gsb, and control signal Gsr.

The plurality of scanning signal lines GL includes scanning signal lines GLA, GLB, and reset wiring GLR. Each of the multiple scanning signal lines GL extends in the X direction. The scanning signal line GLA is connected to the gate electrode of the output switch BCT. When the control signal Gsb is supplied to the scanning signal line GLA, the output switch BCT is turned on. The scanning signal line GLB is connected to the gate electrode of the pixel switch SST. When the control signal Gss is supplied to the scanning signal line GLB, the pixel switch SST is turned on. The reset wiring GLR is connected between the output switch BCT and the drive transistor DRT and to the drain electrode of the reset switch RST. When a control signal Gsr, which is a reset signal, is supplied to the gate electrode of the reset switch RST, a reset potential is supplied to the reset wiring GLR.

The pixel PIX has a storage capacitor Cs and an auxiliary capacitor Cad. Each of the holding capacitor Cs and the auxiliary capacitor Cad is a capacitor. The holding capacitor Cs is connected between the gate electrode of the drive 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 modification example, the auxiliary capacitor Cad may not be arranged.

<Peripheral Structure of LED Element>
Next, the peripheral structure of the LED element arranged in the pixel PIX shown in FIG. 1 will be described. 3 is an enlarged cross-sectional view showing an example of a peripheral structure of an LED element arranged in each of a plurality of pixels of the display device shown in FIG. 1. FIG. FIG. 4 is an enlarged cross-sectional view showing a modified example of the LED element shown in FIG.

The array substrate SUB1 shown in FIG. 3 is a substrate including a substrate 10 and a plurality of insulating layers laminated on the substrate 10. As shown in FIG. 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. As shown in FIG. Also, the array substrate SUB1 includes various circuits included in the pixel PIX described with reference to FIG. Substrate 10 has a surface 10f and a surface 10b opposite surface 10f. Each of inorganic insulating layer 11 , organic insulating layer 12 , and organic insulating layer 13 is laminated on surface 10 f of substrate 10 .

Each of the inorganic insulating layer 11, the organic insulating layer 12, and the organic insulating layer 13 may be a laminated film composed of a plurality of laminated insulating films. For example, the semiconductor layers of the thin film transistors forming the output switch BCT, the drive transistor DRT, and the pixel switch SST shown in FIG. 2 are formed in the inorganic insulating layer 11 . Some of the plurality of inorganic insulating films forming the inorganic insulating layer 11 are used as base layers for forming thin film transistors, and other parts are used as gate insulating films of the thin film transistors.

As shown in FIG. 3, LED elements 20 are mounted on the array substrate SUB1. The LED element 20 has a surface 20f and a surface 20b opposite to the surface 20f. The LED element 20 also includes a plurality of (two in FIG. 3) electrodes 20E arranged on the surface 20b. The plurality of electrodes 20E includes anode electrodes 20EA and cathode electrodes 20EK. The anode electrode 20EA is connected to the terminal 30H via the conductive bonding material 40. As shown in FIG. Cathode electrode 20EK is connected to terminal 30L via conductive bonding material 40 . The conductive bonding material 40 is made of solder, for example. Although one LED element is illustrated in FIG. 3, a plurality of LED elements are mounted in a matrix on the array substrate SUB1. The display device DSP1 displays an image by driving a plurality of LED elements 20 mounted on the array substrate SUB1. Light emitted from the LED element 20 is emitted from, for example, the surface 20f side.

As an example of the LED element 20, FIG. 3 shows an example in which both the anode electrode 20EA and the cathode electrode 20EK are arranged on the surface 20b. However, there are various modifications of the structure of the LED element 20 . For example, in the LED element 20M1 shown in FIG. 4, the cathode electrode 20EK is provided on the surface 20f, and the anode electrode 20EA is provided on the surface 20b. When the LED element 20 shown in FIG. 3 is replaced with the LED element 20M1 shown in FIG. 4, the terminal 30L (see FIG. 3) connected to the cathode electrode 20EK is provided on the surface 20f of the LED element 20M1.

<Method for manufacturing LED display device>
Next, a method for manufacturing the display device DSP1 shown in FIG. 1 will be described. FIG. 5 is an explanatory diagram showing the flow of the manufacturing process of the display device shown in FIG. In the flow illustrated in FIG. 5, for example, a method of sequentially mounting three types of LED elements for red, green, and blue on an array substrate will be described. However, as will be described later as a modified example, there is also a method of collectively mounting a plurality of types of LED elements on an array substrate using a holding substrate in which a plurality of types of LED elements 20 are arranged in a matrix.

<LED Holding Substrate Preparing Step and Array Substrate Preparing Step>
In the LED holding substrate preparation step shown in FIG. 5, substrates SS1, SS2, and SS3 shown in FIG. 6 are prepared. 6 is a plan view showing an outline of a substrate prepared in the LED holding substrate preparation step shown in FIG. 5. FIG. Each of the substrate SS1, the substrate SS2, and the substrate SS3 has an upper surface and a lower surface. Each of the substrate SS1, the substrate SS2, and the substrate SS3 has a plurality of LED elements arranged in a matrix on either one of the upper surface and the lower surface (on the upper surface in the example shown in FIG. 6).

Specifically, different types of LED elements are arranged on the substrate SS1, the substrate SS2, and the substrate SS3. In other words, each of the substrate SS1, the substrate SS2, and the substrate SS3 is an LED holding substrate holding a plurality of LED elements. For example, on the top surface SS1t of the substrate SS1, the first inorganic light emitting elements 21, which are one of the LED elements for red, LED elements for green, and LED elements for blue, are arranged. On the top surface SS2t of the substrate SS2, the second inorganic light emitting elements 22, which are LED elements different from the first inorganic light emitting elements 21 among the LED elements for red, LED elements for green, and LED elements for blue, are arranged. . On the upper surface SS3t of the substrate SS3, a third inorganic light emitting element which is an LED element different from the first inorganic light emitting element 21 and the second inorganic light emitting element among the red LED element, the green LED element, and the blue LED element 23 are arranged.

A plurality of first inorganic light emitting elements 21 are arranged in a matrix on the top surface SS1t of the substrate SS1. The second inorganic light emitting element 22 and the third inorganic light emitting element 23 are not arranged on the top surface SS1t of the substrate SS1. A plurality of second inorganic light emitting elements 22 are arranged in a matrix on the top surface SS2t of the substrate SS2. The first inorganic light emitting element 21 and the third inorganic light emitting element 23 are not arranged on the top surface SS2t of the substrate SS2. A plurality of third inorganic light emitting elements 23 are arranged in a matrix on the top surface SS3t of the substrate SS3. The first inorganic light emitting element 21 and the second inorganic light emitting element 22 are not arranged on the top surface SS3t of the substrate SS3. Each of the substrate SS1, the substrate SS2, and the substrate SS3 is, for example, a sapphire substrate. Each of the first inorganic light emitting element 21, the second inorganic light emitting element 22, and the third inorganic light emitting element 23 is formed, for example, by laminating a metal film, an insulating film, a semiconductor film, or the like on a sapphire substrate. .

In FIG. 6, the planar shapes of the substrate SS1, the substrate SS2, and the substrate SS3 are illustrated as being circular, but the planar shapes of the substrate SS1, the substrate SS2, and the substrate SS3 are not limited to circular, and may be rectangular, for example. There are various modifications.

In this embodiment, before the first LED element mounting process, all of the substrates SS1, SS2, and SS3 are prepared in advance, and the thicknesses of all types of substrates are measured in advance. In this method, the thickness of each of the first inorganic light emitting element 21, the second inorganic light emitting element 22, and the third inorganic light emitting element 23 is measured in advance, so that the thinnest LED element (inorganic light emitting element) 20 This is preferable in that the mounting on the array substrate SUB1 can be started from the substrate including the . However, as a modification, all of the substrates SS1, SS2, and SS3 may not be prepared in advance before the first LED element mounting step. For example, the substrate SS2 should be prepared at least before the second LED element mounting step and the thickness thereof should be measured. Also, the substrate SS3 should be prepared at least before the third LED element mounting step, and the thickness of each substrate should be measured.

Also, in the array substrate preparation step, the array substrate SUB1 shown in FIG. 7 is prepared. FIG. 7 is a cross-sectional view showing an outline of the array substrate SUB1 prepared in the array substrate preparation process shown in FIG. As shown in FIG. 7, the array substrate SUB1 has a surface SUBt and a surface SUBb opposite to the surface SUBt. The surface SUBt is a mounting surface on which the plurality of LED elements 20 shown in FIG. 6 are scheduled to be mounted.

The array substrate SUB1 has multiple terminals 30 . The multiple terminals 30 include a terminal (first terminal) 31 to be electrically connected to the first inorganic light emitting element 21 (see FIG. 6). The plurality of terminals 30 includes a terminal (second terminal) 32 to be electrically connected to the second inorganic light emitting element 22 (see FIG. 6). The plurality of terminals 30 also includes a terminal (third terminal) 33 to be electrically connected to the third inorganic light emitting element 23 (see FIG. 6). The terminals 31, 32, and 33 are arranged in a matrix corresponding to the positions of the pixels PIX shown in FIG.

The order of the array substrate preparation step and the holding substrate preparation step is not limited as long as it precedes the thickness measurement step shown in FIG. For example, the holding substrate preparation process and the array substrate preparation process can be performed simultaneously (in parallel).

<Thickness measurement process>
Next, the thickness measurement process shown in FIG. 5 will be described. FIG. 8 is a cross-sectional view schematically showing an example of a measurement point in the thickness measurement process shown in FIG. FIG. 9 is an explanatory diagram showing an example of a thickness measuring method in the thickness measuring process shown in FIG.

In this step, the substrate SS1, the substrate SS2 or the substrate SS3 shown in FIG. 6 and the array substrate SUB1 shown in FIG. Collect data for controlling the amount of pressing. Therefore, in this step, the thickness is measured at each portion shown in FIG. In this step, the thickness TSUB of the array substrate SUB1 is measured. The thickness TSUB is the shortest distance between the surface (first surface) SUBt and the surface (second surface) SUBb of the array substrate SUB1. The surface SUBt is the top surface of the organic insulating layer 13, the top surface of the terminal 31, the top surface of the terminal 32, or the top surface of the terminal 33, as shown in FIG. The surface SUBb is the lower surface 10b of the substrate 10, as shown in FIG.

Also, in this step, the thickness TSS1 of the substrate SS1 is measured. The thickness TSS1 of the substrate SS1 is the shortest distance between the top surface SS1t and the bottom surface SS1b of the substrate SS1. Also, in this step, the thickness T21 of one or more first inorganic light emitting elements 21 among the plurality of first inorganic light emitting elements 21 arranged on the substrate SS1 is measured. The thickness T21 of the first inorganic light emitting element 21 is the shortest distance between the surface 20f and the surface 20b shown in FIG. 3, or the shortest distance between the surface 20f and the surface of the electrode 20E facing the substrate SUB1. However, the shortest distance between the surface 20b of the first inorganic light emitting element 21 or the surface of the electrode 20E facing the substrate SUB1 and the bottom surface SS1b of the substrate SS1 is measured, and the difference between this measurement result and the thickness TSS1 of the substrate SS1 is 1 may be regarded as the thickness T21 of the inorganic light emitting element 21 .

Also, in this step, the thickness TSS2 of the substrate SS2 is measured. The thickness TSS2 of the substrate SS2 is the shortest distance between the top surface SS2t and the bottom surface SS2b of the substrate SS2. Also, in this step, the thickness T22 of one or more second inorganic light emitting elements 22 among the plurality of second inorganic light emitting elements 22 arranged on the substrate SS2 is measured. The thickness T22 of the second inorganic light emitting element 22 is the shortest distance between the surface 20f and the surface 20b shown in FIG. 3, or the shortest distance between the surface 20f and the surface of the electrode 20E facing the substrate SUB1. However, the shortest distance between the surface 20b of the second inorganic light emitting element 22 or the surface of the electrode 20E facing the substrate SUB1 and the bottom surface SS2b of the substrate SS2 is measured, and the difference between this measurement result and the thickness TSS2 of the substrate SS2 is 2 may be regarded as the thickness T22 of the inorganic light emitting element 22 .

Also, in this step, the thickness TSS3 of the substrate SS3 is measured. The thickness TSS3 of the substrate SS3 is the shortest distance between the top surface SS3t and the bottom surface SS3b of the substrate SS3. Also, in this step, the thickness T23 of one or more third inorganic light emitting elements 23 among the plurality of third inorganic light emitting elements 23 arranged on the substrate SS3 is measured. The thickness T23 of the third inorganic light emitting element 23 is the shortest distance between the surface 20f and the surface 20b shown in FIG. 3, or the shortest distance between the surface 20f and the surface of the electrode 20E facing the substrate SUB1. However, the shortest distance between the surface 20b of the third inorganic light emitting element 23 or the surface of the electrode 20E facing the substrate SUB1 and the lower surface SS3b of the substrate SS3 is measured, and the difference between this measurement result and the thickness TSS3 of the substrate SS3 is 3 may be regarded as the thickness T23 of the inorganic light emitting element 23 .

By the way, in this step, each of the thickness TSS1, the thickness TSS2, and the thickness TSS3 may be measured at a plurality of points. In this case, since the reliability of the measurement result is improved, the pressing force can be precisely controlled in each of the first LED element mounting process, the second LED element mounting process, and the third LED element mounting process, which will be described later. However, since each of the plurality of LED elements 20 formed on one sapphire substrate is collectively formed at the same timing, the thickness of the plurality of LED elements 20 formed on the same sapphire substrate may vary. difference is less likely to occur. Therefore, considering work efficiency, the thickness of one LED element among the plurality of LED elements 20 (for example, the thickness T21 of one first inorganic light emitting element 21 among the plurality of first inorganic light emitting elements 21, The thickness T22 of one second inorganic light emitting element 22 among the plurality of second inorganic light emitting elements 22 and the thickness T23 of one third inorganic light emitting element 23 among the plurality of third inorganic light emitting elements 23) are Measurement is preferred.

A method for measuring the thickness in this step is not particularly limited. However, the thickness of the LED element 20 is about 100 μm to 200 μm. For this reason, the thickness measurement accuracy in this process must be measured on the order of μm. In the first LED element mounting process, the second LED element mounting process, and the third LED element mounting process, which will be described later, if there is a deviation of several μm in the thickness of each measurement location shown in FIG. because there is

As an example of a method capable of measuring the thickness on the order of μm and efficiently measuring the thickness, a method of measuring a workpiece (object to be measured) sandwiched between two sensor heads can be exemplified. In the example shown in FIG. 9, the workpiece 51 is arranged between the sensor head 50A and the sensor head 50B which are arranged at positions facing each other. The work 51 corresponds to each of the array substrate SUB1, substrate SS1, substrate SS2, and substrate SS3 shown in FIG. A laser beam 52 is emitted toward the workpiece 51 from each of the sensor heads 50A and 50B. Light reflected by the surface 51t of the work 51 is detected by the sensor head 50A, and light reflected by the surface 51b of the work 51 is detected by the sensor head 50B. 53A and the distance 53B from the sensor head 50B to the surface 51b of the workpiece 51 are measured. Further, since the separation distance 53C between the sensor heads 50A and 50B is set in advance, the thickness T51 of the work 51 can be calculated by subtracting the values of the distances 53A and 53B from the separation distance 53C. .

However, as described above, various modifications other than the method shown in FIG. 9 are applicable as long as the thickness can be measured on the order of μm. For example, when the work 51 is made of a material that allows the laser beam 52 to pass therethrough, the light reflected by the surfaces 51t and 51b of the work 51 is measured, and the thickness is measured from the interference difference between the reflected lights. There is Further, for example, in the case of the method described above, the laser beam 52 needs to be reflected by the surface of the workpiece 51 . Therefore, if the workpiece 51 is a member that does not easily reflect the laser beam 52, it may be preferable to adopt another method. Other methods include, for example, a measurement method using ultrasonic waves.

<First LED element mounting step>
Next, the first LED element mounting process shown in FIG. 5 will be described. 10 is a cross-sectional view schematically showing a state in which the substrate on which the first inorganic light emitting elements are arranged and the array substrate are pressed together in the first LED element mounting step shown in FIG. 5. FIG.

In the first LED element mounting step, the substrate SS1 held on the stage 61 and the array substrate SUB1 held on the stage 62 face each other, and each of the plurality of first inorganic light emitting elements 21 and the array substrate SUB1 are mounted. By pressing, the plurality of terminals 31 (see FIG. 7) of the array substrate SUB1 and the plurality of first inorganic light emitting elements 21 are electrically connected.

The stage 61 is a member capable of holding the substrate SS1. A lower surface SS1b of the substrate SS1 is held by a holding surface 61h of the stage 61 . The stage 62 is a member 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. As shown in FIG. As a method for holding the substrate SS1 by the stage 61 and a method for holding the array substrate SUB1 by the stage 62, for example, a method of holding by suction, or a method of fixing the peripheral portion of the substrate SS1 or the array substrate SUB1 with a fixing jig (not shown). methods, etc. can be exemplified.

A holding surface 61h of the stage 61 and a holding surface 62h of the stage 62 face each other. Therefore, when the lower surface SS1b of the substrate SS1 is held by the holding surface 61h and the surface SUBb of the array substrate SUB1 is held by the holding surface 62h, as shown in FIG. The surface SUBt of SUB1 faces each other. Further, each of the stage 61 and the stage 62 has a mechanism capable of moving independently of each other in the plane direction (XY plane direction). In this step, at least one of the stage 61 and the stage 62 is moved in the XY plane direction, and each of the electrodes 20E (see FIG. 3) provided for the plurality of first inorganic light emitting elements 21 is aligned with the terminal 31 (see FIG. 3) of the array substrate SUB1. (See FIG. 3). At this time, the conductive bonding material 40 is already bonded to the electrode 20E shown in FIG. Therefore, when alignment is performed in the direction along the XY plane, the terminal 31 faces the conductive bonding material 40 bonded to the electrode 20E of the first inorganic light emitting element 21 .

When the distance between the stage 61 and the stage 62 is shortened in a state after the alignment in the direction along the XY plane, the plurality of first inorganic light-emitting diodes arranged on the upper surface SS1t of the substrate SS1 are displayed. Each of the elements 21 approaches the array substrate SUB1. At this time, each of the plurality of conductive bonding materials 40 shown in FIG. 3 contacts the terminal 31 . In this state, the conductive bonding material 40 is bonded to the terminals 31 by, for example, reflow treatment (heating treatment). are electrically connected via

Here, in order to connect the plurality of conductive bonding materials 40 and the plurality of terminals 31 respectively, reflow processing is performed while an appropriate load is applied to the contact surface between the conductive bonding materials 40 and the terminals 31 . There is a need to do. For example, if the pressing force for pressing the first inorganic light-emitting element 21 and the array substrate SUB1 is insufficient, the conductive bonding material 40 and the terminal 31 will not bond well, which may cause a decrease in electrical connection reliability. Become. On the other hand, if the pressing force for pressing the first inorganic light emitting element 21 and the array substrate SUB1 is excessively large, the first inorganic light emitting element 21 itself or members around the conductive bonding material 40 may be damaged. The LED element 20 shown in FIG. 3 is a micro LED element and has a small external size. Therefore, even if the positional relationship between the conductive bonding material 40 and the terminal 31 is deviated by several μm in the Z direction shown in FIG. In particular, errors in the thickness of the LED elements may occur due to differences in manufacturing conditions for the LED elements 20 . Therefore, when the manufacturing lot is changed, the thickness of the LED element 20 may deviate from the design value, for example, on the order of μm.

In the case of this embodiment, as described with reference to FIGS. 5 to 9, the thickness measurement process is performed before the first LED element mounting process, and the thickness TSUB of the array substrate SUB1 and the substrate SS1 shown in FIG. and the thickness T21 of the first inorganic light emitting element 21 are measured. In addition, in the first LED element mounting process of the present embodiment, the pressing amount for pressing each of the plurality of first inorganic light emitting elements 21 and the array substrate SUB1 is controlled based on the result measured in the thickness measuring process. For example, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS1 of the substrate SS1, and the thickness T21 of the first inorganic light emitting element 21 is smaller than the design value, the stage 61 and the stage 62 are moved closer together. The final separation distance after the separation is controlled to be smaller than a preset value. That is, the pressing amount for pressing the first inorganic light emitting element 21 and the array substrate SUB1 is reduced. The extent to which the pushing amount is reduced is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS1 of the substrate SS1, and the thickness T21 of the first inorganic light emitting element 21, and the design value. Defined. On the other hand, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS1 of the substrate SS1, and the thickness T21 of the first inorganic light emitting element 21 is larger than the design value, the stage 61 and the stage 62 are moved closer together. The final separation distance after the separation is controlled to be larger than a preset value. That is, the pressing amount for pressing the first inorganic light emitting element 21 and the array substrate SUB1 is increased. The extent to which the pushing amount is increased is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS1 of the substrate SS1, and the thickness T21 of the first inorganic light emitting element 21 and the design value. Defined. As a result, the reflow process can be performed with an appropriate load applied to the contact surface between the conductive bonding material 40 and the terminal 31 shown in FIG. As a result, the reliability of electrical connection between the electrodes 20E of the first inorganic light emitting element 21 and the terminals 31 via the conductive bonding material 40 can be improved.

By the way, the example shown in FIG. 10 exemplifies an embodiment in which the pressing force is applied by pushing down the stage 61 in the direction of the stage 62, but there are various modifications of the method of applying the pressing force. be. For example, there is a method of pushing up the stage 62 in the direction of the stage 61, or a method of moving each of the stages 61 and 62 in the Z direction.

<First Holding Substrate Detachment Step>
Next, the first holding substrate peeling process shown in FIG. 5 will be described. 11 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of first inorganic light emitting elements in the first holding substrate peeling step shown in FIG. 5. FIG. In the first holding substrate peeling process, as shown in FIG. 11, the substrate SS1 and the plurality of first inorganic light emitting elements 21 are peeled off after the first LED element mounting process.

A technique called laser lift-off, for example, can be used as a method for separating the adhered interface between the upper surface SS1t of the substrate SS1, which is the holding substrate, and the plurality of first inorganic light-emitting elements 21 . When using a technique called laser lift-off, for example, an ultraviolet laser beam is irradiated from the lower surface SS1b side of the substrate SS1 toward the adhesion interface between the upper surface SS1t of the substrate SS1 and the plurality of first inorganic light emitting elements 21 . A gallium nitride layer is formed on the surface 20b of the first inorganic light emitting element 21 (see FIG. 3). When the surface 20b of the first inorganic light emitting element 21 is irradiated with the ultraviolet laser light, the surface layer (part of the surface 20b side) of the gallium nitride layer is modified, and the substrate SS1 and the first inorganic light emitting element 21 are separated. becomes possible.

Through this process, a structure in which a plurality of first inorganic light emitting elements 21 are mounted on the array substrate SUB1 is obtained.

<Second LED element mounting process>
Next, the second LED element mounting process shown in FIG. 5 will be described. 12 is a cross-sectional view schematically showing a state in which the substrate on which the second inorganic light emitting elements are arranged and the array substrate are pressed together in the second LED element mounting step shown in FIG. 5. FIG.

In the second LED element mounting process, the substrate SS2 held on the stage 61 and the array substrate SUB1 held on the stage 62 are opposed to each other, and each of the plurality of second inorganic light emitting elements 22 and the array substrate SUB1 are mounted. By pressing, the plurality of terminals 32 (see FIG. 7) of the array substrate SUB1 and the plurality of second inorganic light emitting elements 22 are electrically connected.

A lower surface SS2b of the substrate SS2 is held by a holding surface 61h of the stage 61 . The stage 62 is a member capable of holding the array substrate SUB1. The array substrate SUB1 on which the plurality of first inorganic light emitting elements 21 are already mounted is held by the holding surface 62h of the stage 62 on the surface SUBb side. As already explained, there are various methods for holding the substrate SS2 by the stage 61 and for holding the array substrate SUB1 by the stage 62 .

A holding surface 61h of the stage 61 and a holding surface 62h of the stage 62 face each other. Therefore, in a state where the lower surface SS2b of the substrate SS2 is held by the holding surface 61h and the surface SUBb of the array substrate SUB1 is held by the holding surface 62h, as shown in FIG. The surface SUBt of SUB1 faces each other. As described above, each of the stage 61 and the stage 62 has a mechanism capable of moving independently of each other in the plane direction (XY plane direction). In this step, at least one of the stage 61 and the stage 62 is moved in the XY plane direction so that each of the electrodes 20E (see FIG. 3) included in the plurality of second inorganic light emitting elements 22 is aligned with the terminal 32 (see FIG. 3) of the array substrate SUB1. (See FIG. 3). At this time, the conductive bonding material 40 is already bonded to the electrode 20E shown in FIG. Therefore, when alignment is performed in the direction along the XY plane, the terminal 32 faces the conductive bonding material 40 bonded to the electrode 20E of the second inorganic light emitting element 22 .

When the distance between the stage 61 and the stage 62 is shortened in a state after the alignment in the direction along the XY plane, a plurality of second inorganic light-emitting devices arranged on the upper surface SS2t of the substrate SS2 are displayed. Each of the elements 22 approaches the array substrate SUB1. At this time, each of the plurality of conductive bonding materials 40 shown in FIG. 3 contacts the terminal 32 . In this state, the conductive bonding material 40 is bonded to the terminals 32 by, for example, reflow treatment (heating treatment). are electrically connected via

In the case of this embodiment, the thickness measurement process is performed before the second LED element mounting process, and the thickness TSUB of the array substrate SUB1, the thickness TSS2 of the substrate SS2 and the thickness TSS2 of the substrate SS2 shown in FIG. Measure the thickness T22. In addition, in the second LED element mounting process of the present embodiment, the pressing amount for pressing each of the plurality of second inorganic light emitting elements 22 and the array substrate SUB is controlled based on the result measured in the thickness measuring process. For example, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS2 of the substrate SS2, and the thickness T22 of the second inorganic light emitting element 22 is smaller than the design value, the stage 61 and the stage 62 are moved closer together. The final separation distance after the separation is controlled to be smaller than a preset value. That is, the pressing amount for pressing the second inorganic light emitting element 22 and the array substrate SUB1 is reduced. The extent to which the pushing amount is reduced is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS2 of the substrate SS2, and the thickness T22 of the first inorganic light emitting element 22 and the design value. Defined. On the other hand, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS2 of the substrate SS2, and the thickness T22 of the second inorganic light emitting element 22 is larger than the design value, the stage 61 and the stage 62 are moved closer to each other. The final separation distance after the separation is controlled to be larger than a preset value. That is, the pressing amount for pressing the second inorganic light emitting element 22 and the array substrate SUB1 is increased. The extent to which the pushing amount is increased is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS2 of the substrate SS2, and the thickness T22 of the second inorganic light emitting element 22 and the design value. Defined. As a result, the reflow process can be performed with an appropriate load applied to the contact surface between the conductive bonding material 40 and the terminal 32 shown in FIG. As a result, the reliability of the electrical connection between the electrode 20E of the second inorganic light emitting element 22 and the terminal 32 via the conductive bonding material 40 can be improved.

Moreover, it is preferable that the thickness T21 (see FIG. 8) of each of the plurality of first inorganic light emitting elements 21 is equal to or less than the thickness T22 (see FIG. 8) of each of the plurality of second inorganic light emitting elements 22 . The second LED element mounting process is performed in a state where the plurality of first inorganic light emitting elements 21 are already mounted on the array substrate SUB1. Therefore, in this step, from the viewpoint of suppressing damage to the plurality of first inorganic light emitting elements 21 sandwiched between the substrate SS2 and the array substrate SUB1, it is particularly preferable that the thickness T21 is thinner than the thickness T22. preferable.

<Second Holding Substrate Peeling Step>
Next, the second holding substrate peeling process shown in FIG. 5 will be described. 13 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of second inorganic light emitting elements in the second holding substrate peeling step shown in FIG. 5. FIG. In the second holding substrate peeling process, as shown in FIG. 13, the substrate SS2 and the plurality of second inorganic light emitting elements 22 are peeled off after the second LED element mounting process. As a method for peeling off the adhesion interface between the upper surface SS2t of the substrate SS2, which is the holding substrate, and the plurality of second inorganic light-emitting elements 22, a technique called laser lift-off, for example, can be used in the same manner as the above-described first holding substrate peeling step. can be done. Through this step, a structure in which the plurality of first inorganic light emitting elements 21 and the plurality of second inorganic light emitting elements 22 are mounted on the array substrate SUB1 is obtained.

<Third LED element mounting step>
Next, the third LED element mounting step shown in FIG. 5 will be described. 14 is a cross-sectional view schematically showing a state in which the substrate on which the third inorganic light emitting elements are arranged and the array substrate are pressed together in the third LED element mounting step shown in FIG. 5. FIG.

In the third LED element mounting step, the substrate SS3 held on the stage 61 and the array substrate SUB1 held on the stage 62 are opposed to each other, and each of the plurality of third inorganic light emitting elements 23 and the array substrate SUB1 are mounted. By pressing, the plurality of terminals 33 (see FIG. 7) of the array substrate SUB1 and the plurality of third inorganic light emitting elements 23 are electrically connected.

The lower surface SS3b of the substrate SS3 is held by the holding surface 61h of the stage 61. As shown in FIG. The stage 62 is a member capable of holding the array substrate SUB1. The array substrate SUB1 on which the plurality of first inorganic light emitting elements 21 and the plurality of second inorganic light emitting elements 22 are already mounted is held by the holding surface 62h of the stage 62 on the surface SUBb side. As already explained, there are various methods for holding the substrate SS3 by the stage 61 and for holding the array substrate SUB1 by the stage 62 .

A holding surface 61h of the stage 61 and a holding surface 62h of the stage 62 face each other. Therefore, in a state where the lower surface SS3b of the substrate SS3 is held by the holding surface 61h and the surface SUBb of the array substrate SUB1 is held by the holding surface 62h, as shown in FIG. The surface SUBt of SUB1 faces each other. As described above, each of the stage 61 and the stage 62 has a mechanism capable of moving independently of each other in the plane direction (XY plane direction). In this step, at least one of the stage 61 and the stage 62 is moved in the XY plane direction so that each of the electrodes 20E (see FIG. 3) provided for the plurality of third inorganic light emitting elements 23 is aligned with the terminal 33 (see FIG. 3) of the array substrate SUB1. (See FIG. 3). At this time, the conductive bonding material 40 is already bonded to the electrode 20E shown in FIG. Therefore, when alignment is performed in the direction along the XY plane, the terminal 33 faces the conductive bonding material 40 bonded to the electrode 20E of the third inorganic light emitting element 23 .

When the distance between the stage 61 and the stage 62 is shortened in the state after the alignment in the direction along the XY plane, the plurality of third inorganic light-emitting devices arranged on the upper surface SS3t of the substrate SS3 Each of the elements 23 approaches the array substrate SUB1. At this time, each of the plurality of conductive bonding materials 40 shown in FIG. 3 contacts the terminal 33 . In this state, the conductive bonding material 40 is bonded to the terminals 33 by, for example, reflow treatment (heating treatment). are electrically connected via

In the case of this embodiment, the thickness measurement process is performed before the third LED element mounting process, and the thickness TSUB of the array substrate SUB1, the thickness TSS3 of the substrate SS3, and the third inorganic light emitting element 23 shown in FIG. Measure the thickness T23. In addition, in the third LED element mounting process of the present embodiment, the pressing amount for pressing each of the plurality of third inorganic light emitting elements 23 and the array substrate SUB is controlled based on the result measured in the thickness measuring process. For example, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS3 of the substrate SS3, and the thickness T23 of the third inorganic light emitting element 23 is smaller than the design value, the stage 61 and the stage 62 are moved closer to each other. The final separation distance after the separation is controlled to be smaller than a preset value. That is, the pressing amount for pressing the third inorganic light emitting element 23 and the array substrate SUB1 is reduced. The extent to which the pushing amount is reduced is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS3 of the substrate SS3, and the thickness T23 of the first inorganic light emitting element 23 and the design value. Defined. On the other hand, when the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS3 of the substrate SS3, and the thickness T23 of the third inorganic light emitting element 23 is larger than the design value, the stage 61 and the stage 62 are moved closer to each other. The final separation distance after the separation is controlled to be larger than a preset value. That is, the pressing amount for pressing the third inorganic light emitting element 23 and the array substrate SUB1 is increased. The extent to which the pushing amount is increased is based on the difference between the total value of the measurement results of the thickness TSUB of the array substrate SUB1, the thickness TSS3 of the substrate SS3, and the thickness T23 of the third inorganic light emitting element 23 and the design value. Defined. As a result, the reflow process can be performed while applying an appropriate load to the contact surface between the conductive bonding material 40 and the terminal 33 shown in FIG. As a result, the reliability of the electrical connection between the electrode 20E of the third inorganic light emitting element 23 and the terminal 33 via the conductive bonding material 40 can be improved.

Moreover, it is preferable that the thickness T21 (see FIG. 8) of each of the plurality of first inorganic light emitting elements 21 is equal to or less than the thickness T23 (see FIG. 8) of each of the plurality of third inorganic light emitting elements 23 . Moreover, it is preferable that the thickness T22 (see FIG. 8) of each of the plurality of second inorganic light emitting elements 22 is equal to or less than the thickness T23 of each of the plurality of third inorganic light emitting elements 23 . The third LED element mounting process is performed in a state where the plurality of first inorganic light emitting elements 21 and the plurality of second inorganic light emitting elements 22 are already mounted on the array substrate SUB1. Therefore, in this step, from the viewpoint of suppressing damage to the plurality of first inorganic light emitting elements 21 and the plurality of second inorganic light emitting elements 22 sandwiched between the substrate SS3 and the array substrate SUB1, the thickness T21 and It is particularly preferred that each thickness T22 is thinner than the thickness T23.

<Third Holding Substrate Peeling Step>
Next, the third holding substrate peeling process shown in FIG. 5 will be described. 15 is a cross-sectional view schematically showing a state in which the holding substrate is peeled off from the plurality of third inorganic light emitting elements in the third holding substrate peeling step shown in FIG. 5. FIG. In the third holding substrate peeling step, as shown in FIG. 13, after the third LED element mounting step, the substrate SS3 and the plurality of third inorganic light emitting elements 23 are peeled off. As a method for peeling off the adhesion interface between the upper surface SS3t of the substrate SS3, which is the holding substrate, and the plurality of third inorganic light-emitting elements 23, a technique called laser lift-off, for example, can be used in the same manner as the above-described first holding substrate peeling step. can be done. Through this process, a structure in which the plurality of first inorganic light emitting elements 21, the plurality of second inorganic light emitting elements 22, and the plurality of third inorganic light emitting elements 23 are mounted on the array substrate SUB1 is obtained. After this step, a protective film or the like for protecting the plurality of LED elements 20 is formed as necessary, and the display device shown in FIG. 1 is obtained.

As described above, according to the present embodiment, before mounting the plurality of LED elements (inorganic light emitting elements) 20 on the array substrate SUB1, the thickness TSUB of the array substrate SUB1 shown in FIG. The thickness (thickness TSS1, thickness TSS2, and thickness TSS3) of the substrate SS1, the substrate SS2, and the substrate SS3) and the thickness of the LED element 20 (thickness T21, thickness T22, and thickness T23) are By measuring, the pressing force during mounting can be precisely controlled. As a result, the electrical connection reliability between the LED elements 20 and the array substrate SUB1 can be improved.

In the example shown in FIG. 5, an embodiment in which three types of LED elements are mounted in order has been described, but the types of LED elements to be mounted are not limited to three types. For example, when it is sufficient to collectively mount one type of LED element, the steps from the second LED element mounting step to the third holding substrate peeling step shown in FIG. 5 can be omitted. Further, for example, in the case of a method of manufacturing a display device in which two types of LED elements are mounted, the steps from the third LED element mounting step to the third holding substrate peeling step shown in FIG. 5 can be omitted. Further, in the case of a method of manufacturing a display device in which four or more types of LED elements are mounted, after the third holding substrate peeling step shown in FIG. It is obtained by repeatedly performing an LED element mounting process for mounting the element and a holding substrate peeling process.

<Modified Example of Holding Substrate>
As another modification to FIG. 5, a plurality of types (for example, three types) of LED elements may be collectively mounted on the array substrate SUB1. This modification will be described below. FIG. 16 is a modification to FIG. 10, and is a cross-sectional view schematically showing a state before mounting on an array substrate using a holding substrate collectively holding a plurality of types of LED elements.

The substrate SS4 shown in FIG. 16 has a top surface SS4t and a bottom surface SS4b. A plurality of LED elements 20 including a plurality of first inorganic light emitting elements 21, a plurality of second inorganic light emitting elements 22, and a plurality of second inorganic light emitting elements 22 are arranged in a matrix on the upper surface SS4t of the substrate SS4. there is The substrate SS4 is not a substrate for manufacturing the LED element 20, but a mere support substrate, so it need not be a sapphire substrate. For example, a substrate such as a glass substrate can be used. The plurality of LED elements 20 are adhesively fixed onto the upper surface SS4t of the substrate SS4 via an adhesive layer (not shown).

A method of arranging a plurality of LED elements 20 on the upper surface SS4t of the substrate SS4 is, for example, a first inorganic light emitting element 21, a second inorganic light emitting element 22, and a third inorganic light emitting element 23 on the array substrate SUB1 shown in FIG. can be applied by applying the method of sequentially implementing When the LED element 20 is adhesively fixed onto the substrate SS4, no electrical connection or the like is required, so the thickness measurement process can be omitted. However, a thickness measurement process is required before the LED mounting process of pressing the substrate SS4 against the array substrate SUB1.

In the case of this modification, in the thickness measurement process, among the plurality of LED elements 20, so that the LED element 20 with the thinnest thickness and the LED element 20 with the thickest thickness can be detected, a plurality of LED elements Preferably, the thickness is measured for 20. By measuring the thinnest LED element 20 and the thickest LED element 20, it is possible to calculate the allowable margin for the pressing force value in the LED element mounting process.

In the case of this modification, a plurality of types of LED elements 20 are collectively mounted on the array substrate SUB1, so the time required for the LED element mounting process can be shortened compared to the example shown in FIG. However, different types of LED elements 20 may have different thicknesses depending on the type. The production method exemplified in is preferable.

Although the embodiment and representative modifications have been described above, the above technology can be applied to various modifications other than the illustrated modifications. For example, the modifications described above may be combined.

Within the scope of the idea of the present invention, those skilled in the art can conceive of various modifications and modifications, and it is understood that these modifications and modifications also fall within the scope of the present invention. For example, additions, deletions, or design changes of components, or additions, omissions, or changes of conditions to the above-described embodiments by those skilled in the art are also subject to the gist of the present invention. is included in the scope of the present invention as long as it has

INDUSTRIAL APPLICABILITY The present invention can be used for display devices and electronic devices incorporating display devices.

5 control circuit 6 drive circuit 10, SS1, SS2, SS3, SS4 substrate 10b, 10f, 20b, 20f, 51b, 51t surface 11 inorganic insulating layer 12 organic insulating layer 13 organic insulating layer 20, 20M1 LED element (inorganic light emitting element)
20E electrode 20EA anode electrode 20EK cathode electrode 21 first inorganic light emitting element 22 second inorganic light emitting element 23 third inorganic light emitting element 30, 30H, 30L, 31, 32, 33 terminal 40 conductive bonding material 50A, 50B sensor head 51 work 52 Laser beams 53A, 53B Distance 53C Spacing distances 61, 62 Stages 61h, 62h Holding surface BCT Output switch Cad Auxiliary capacitor Cs Holding capacitor DA Display area DRT Drive transistor DSP1 Display device EK Cathode electrodes GL, GLA, GLB Scanning signal line GLR Reset Wiring Gsb, Gsr, Gss Control signal IC Driver LED Micro PFA Peripheral area PIX Pixel PVD, PVS Potential RST Reset switch SS1b, SS2b, SS3b, SS4b Lower surface SS1t, SS2t, SS3t, SS4t Upper surface SST Pixel switch SUB1 Array substrate SUBb Surface (first 2 sides)
SUBt surface (first surface)
VL Video signal line Vsg Video signal

Claims (4)

(a) preparing a first substrate on which a plurality of first inorganic light emitting devices are arranged in a matrix and an array substrate on which a plurality of first terminals are formed;
(b) measuring the thickness of the first substrate, the thickness of one or more first inorganic light emitting devices among the plurality of first inorganic light emitting devices, and the thickness of the array substrate;
(c) with the first substrate held on the first stage and the array substrate held on the second stage facing each other, each of the plurality of first inorganic light emitting elements and the array substrate are separated; electrically connecting the plurality of first terminals of the array substrate and the plurality of first inorganic light emitting elements by pressing;
(d) after the step (c), separating the first substrate and the plurality of first inorganic light emitting elements;
including
The method of manufacturing a display device, wherein in the step (c), a pressing amount for pressing each of the plurality of first inorganic light emitting elements and the array substrate is controlled based on the result of the measurement in the step (b). In claim 1,
a plurality of second terminals are further formed on the array substrate prepared in the step (a);
(e) preparing a second substrate on which a plurality of second inorganic light emitting devices are arranged in a matrix;
(f) measuring the thickness of the second substrate and the thickness of one or more second inorganic light emitting elements among the plurality of second inorganic light emitting elements;
(g) after the steps (d), (e), and (f), the second substrate held on the first stage and the array substrate held on the second stage; are opposed to each other, and the plurality of second terminals of the array substrate and the plurality of second inorganic light emitting elements are electrically connected by pressing each of the plurality of second inorganic light emitting elements against the array substrate. connecting to
(h) a step of separating the second substrate and the plurality of second inorganic light emitting elements after the step (g);
including
A display device, wherein in the step (g), a pressing amount for pressing each of the plurality of second inorganic light emitting elements and the array substrate is controlled based on the results measured in the steps (b) and (f). manufacturing method. In claim 2,
a plurality of third terminals are further formed on the array substrate prepared in the step (a);
(i) preparing a third substrate on which a plurality of third inorganic light emitting devices are arranged in a matrix;
(k) measuring the thickness of the third substrate and the thickness of one or more third inorganic light emitting elements among the plurality of third inorganic light emitting elements;
(m) after the steps (h), (i), and (k), the third substrate held on the first stage and the array substrate held on the second stage; are opposed to each other, and the plurality of third terminals of the array substrate and the plurality of third inorganic light emitting elements are electrically connected by pressing each of the plurality of third inorganic light emitting elements against the array substrate. connecting to
(n) a step of separating the third substrate and the plurality of third inorganic light emitting elements after the step (m);
including
A display device, wherein in the step (m), a pressing amount for pressing each of the plurality of third inorganic light emitting elements and the array substrate is controlled based on the results measured in the step (b) and the step (k). manufacturing method. In claim 3,
Each of the (e) step, the (f) step, the (i) step, and the (k) step is performed before the (c) step,
The thickness of the first inorganic light emitting element measured in the step (b) is the thickness of the second inorganic light emitting element measured in the step (f) and the thickness of the second inorganic light emitting element measured in the step (k). thinner than each of the thicknesses of the three inorganic light-emitting elements,
The method of manufacturing a display device, wherein the thickness of the second inorganic light emitting element measured in the step (f) is thinner than the thickness of each of the third inorganic light emitting elements measured in the step (k).

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