JP2023005499A - Led chip formation substrate and transfer method of led chip - Google Patents

Abstract

To provide an LED chip forming substrate including an LED chip for repair.SOLUTION: An LED chip forming substrate includes a first region including a plurality of first LED chips arranged with a first pitch in a first direction, and a second region located on the periphery of the first region and including a plurality of second LED chips arranged with a second pitch greater than the first pitch in the first direction, and the first LED chip and the second LED chip have the same emission color. Also, the number of the plurality of second LED chips is 0.1% or more and 10% or less of the number of the plurality of first LED chips.SELECTED DRAWING: Figure 1A

Description

One embodiment of the present invention relates to an LED chip forming substrate on which LED chips are formed. Further, one embodiment of the present invention relates to an LED chip transfer method for transferring LED chips to a backplane using an LED chip forming substrate.

Display devices using liquid crystals or OLEDs (Organic Light Emitting Diodes) have already been commercialized in small and medium-sized display devices such as smartphones. In particular, an OLED display device using an OLED, which is a self-luminous element, has advantages over a liquid crystal display device in that it has a high contrast and does not require a backlight. However, since the OLED is composed of an organic compound, it is difficult to ensure high reliability of the OLED display device due to deterioration of the organic compound.

In recent years, as a next-generation display device, so-called micro LED display devices (or mini LED display devices) in which minute LED chips are mounted on pixel circuits on a circuit board have been developed (for example, Patent Document 1). An LED is a self-luminous element similar to an OLED, but unlike an OLED, it is composed of an inorganic compound containing gallium (Ga), indium (In), or the like. Therefore, compared with the OLED display device, it is easier to ensure high reliability of the micro LED display device. Furthermore, LED chips have higher luminous efficiency and brightness than OLED displays. Therefore, the micro LED display device is expected as a next-generation display device with high reliability, high brightness, and high contrast.

Unlike the OLED display device, the micro LED display device has a manufacturing process in which the LED chips are transferred to the backplane. For example, Patent Literature 1 discloses a method of transferring a micro LED chip to a backplane by irradiating laser light.

Japanese Patent Publication No. 2019-511838

If a defect occurs during the transfer of the micro LED chip, it is necessary to repair the defective portion. However, the micro LED chip is minute, and it is very difficult to handle the micro LED chip alone. As a result, there has been a problem of a decrease in yield or an increase in manufacturing cost due to repair of defective portions.

SUMMARY OF THE INVENTION In view of the above problems, one object of an embodiment of the present invention is to provide an LED chip forming substrate including an LED chip for repair. Another object of one embodiment of the present invention is to provide an LED chip transfer method capable of performing repair using an LED chip forming substrate.

An LED chip forming substrate according to one embodiment of the present invention includes a first region including a plurality of first LED chips arranged with a first pitch in a first direction; a second region located at the periphery and including second LED chips arranged with a second pitch greater than the first pitch in the first direction; and the second LED chip have the same emission color.

An LED chip transfer method according to an embodiment of the present invention includes a first region including a plurality of first LED chips arranged with a first pitch in a first direction; a second region located at the periphery of the region and including a plurality of second LED chips arranged with a second pitch greater than the first pitch in the first direction. Separating the forming substrate into a first substrate containing the first region and a second substrate containing one of the plurality of second LED chips, and using the first substrate to form the plurality of first LED chips One or more of the chips are transferred to the backplane, and a second substrate is used to transfer one of a plurality of second LED chips to the backplane.

1 is a schematic plan view of an LED chip forming substrate according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of an LED chip forming substrate according to one embodiment of the present invention; FIG. FIG. 4 is a schematic diagram illustrating cutting of the LED chip forming substrate in the LED chip transfer method according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 4B is a schematic diagram illustrating a step of transferring the first LED chip using the first transfer substrate in the method for transferring the LED chip according to the embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a step of transferring a second LED chip using a second transfer board in the method for transferring LED chips according to one embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a step of transferring a second LED chip using a second transfer board in the method for transferring LED chips according to one embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a step of transferring a second LED chip using a second transfer board in the method for transferring LED chips according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a repair process in the method for transferring an LED chip according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a repair process in the method for transferring an LED chip according to one embodiment of the present invention.

Each embodiment of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is only an example. Configurations that can be easily conceived by a person skilled in the art by appropriately changing the configurations of the embodiments while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, in order to make the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual mode. However, the illustrated shape is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, elements similar to those described above with respect to the previous figures may be denoted by the same reference numerals followed by alphabets, and detailed description thereof may be omitted as appropriate.

In this specification, for convenience of explanation, the terms “upper”, “upper”, “lower”, and “lower” are used, but in principle, the substrate on which the structure is formed is used as a reference, and the structure is formed from the substrate. Let the direction toward an object be "up" or "upper". Conversely, the direction from the structure toward the substrate is defined as "down" or "lower". Therefore, in the expression of the structure on the substrate, the surface of the structure facing the substrate is the lower surface of the structure, and the opposite surface is the upper surface of the structure. In addition, the expression "structure on the substrate" merely describes the vertical relationship between the substrate and the structure, and other members may be arranged between the substrate and the structure. Furthermore, the terms "upper" or "upper" or "lower" or "lower" mean the order of stacking in a structure in which a plurality of layers are stacked, even if they are not in an overlapping positional relationship in plan view. good.

In the present specification, "α includes A, B or C", "α includes any one of A, B and C", "α is one selected from the group consisting of A, B and C The expression "including" does not exclude the case where α includes a plurality of combinations of A to C, unless otherwise specified. Furthermore, these expressions do not exclude the case where α contains other elements.

Each of the following embodiments can be combined with each other as long as there is no technical contradiction.

<First Embodiment>
[1. Configuration of LED chip forming substrate 10]
A configuration of an LED chip forming substrate 10 according to an embodiment of the present invention will be described with reference to FIGS. 1A and 1B.

1A and 1B are schematic plan and cross-sectional views of an LED chip forming substrate 10 according to one embodiment of the present invention. Specifically, FIG. 1B is an enlarged cross-sectional view taken along line A1-A2 shown in FIG. 1A.

As shown in FIG. 1A, LED chip forming substrate 10 has first region 110 and second region 120 formed on support substrate 100 . A first region 110 is formed in the central portion of the support substrate 100 . A second region 120 is formed in the peripheral portion of the support substrate 100 . In other words, the second region 120 is formed around the first region 110 .

A plurality of second regions 120 may be formed. In that case, the plurality of second regions 120 may be spaced apart from each other around the first region 110 .

In plan view, each of first region 110 and second region 120 is formed in a rectangular shape. However, each of the first region 110 and the second region 120 can be formed in any shape without being limited to a rectangular shape.

As shown in FIG. 1B, a plurality of first LED chips 200-1 are formed on the support substrate 100 in the first region 110. As shown in FIG. A plurality of second LED chips 200 - 2 are formed on the support substrate 100 in the second region 120 . The first LED chip 200-1 and the second LED chip 200-2 have the same emission color (eg, blue, green, or red). That is, the first LED chip 200-1 and the second LED chip 200-2 have the same structure. Therefore, hereinafter, the first LED chip 200-1 and the second LED chip 200-2 may be described as the LED chip 200 unless otherwise distinguished. Also, in order to explain the difference in emission colors of the LED chips 200, the blue LED chip 200B, the green LED chip 200G, and the red LED chip 200R may be described.

Each layer (for example, a cathode electrode, an n-type semiconductor layer, a light-emitting layer, a p-type semiconductor layer, an anode electrode, etc.) forming the LED chip 200 is formed on the support substrate 100 . Therefore, the support substrate 100 is preferably a substrate on which each layer can be crystal-grown. The support substrate 100 is, for example, a sapphire substrate. However, the configuration of the support substrate 100 is not limited to this. The support substrate 100 may be a substrate onto which an LED chip 200 formed using another substrate is transferred. In this case, a light-transmitting substrate such as a glass substrate, a quartz substrate, or a resin substrate can be used as the supporting substrate 100 . As the resin substrate, a flexible substrate such as a polyimide substrate, an acrylic substrate, a siloxane substrate, or a fluororesin substrate can be used. Note that when the LED chip 200 is transferred to the backplane using a laser beam, the support substrate 100 is preferably a translucent substrate that transmits the laser beam. Note that the “backplane” refers to a substrate on which a circuit for controlling the LED chips 200 is formed. The backplane may have a conductive adhesive member on the electrodes that electrically connect with the circuit.

A release layer 210 is provided between the support substrate 100 and the LED chip 200 . When transferring the LED chip 200 to the backplane, the LED chip 200 is separated from the support substrate 100 at the release layer 210 . The release layer 210 is, for example, a gallium nitride thin film. A gallium nitride thin film can absorb laser light with a wavelength of 248 nm. Therefore, when the peeling layer 210 is a gallium nitride thin film, the gallium nitride is decomposed into metal gallium and nitrogen gas when irradiated with a laser beam having a wavelength of 248 nm, and the LED chip 200 can be separated from the support substrate 100 . In other words, the LED chip 200 can be lifted off.

Although the release layer 210 shown in FIG. 1B is provided in an island shape for each LED chip 200, the configuration of the release layer 210 is not limited to this. The release layer 210 may be provided over the entire surface of the first region 110 and the second region 120 . The release layer 210 may be provided as necessary, and the LED chip forming substrate 10 may be configured without the release layer 210 .

A connection member 220 is provided on the LED chip 200 . The connection member 220 is electrically connected to the electrodes of the backplane when the LED chip 200 is transferred to the backplane. Therefore, the connection member 220 has conductivity, and is, for example, silver paste, solder (Sn), paste containing metal nanoparticles, anisotropic conductive film (ACF), or the like. The connection member 220 may be provided as necessary, and the LED chip forming substrate 10 may be configured without the connection member 220 .

As described above, the first LED chip 200-1 and the second LED chip 200-2 have the same structure. However, the plurality of first LED chips 200-1 formed in the first region 110 and the plurality of second LED chips 200-2 formed in the second region 120 have different pitches. In the first direction (x-axis direction), the plurality of first LED chips 200-1 and the plurality of second LED chips 200-2 have a first pitch p1 and a second pitch p2, respectively. ing. The second pitch p2 is greater than the first pitch p1. Although not shown, in a second direction (y-axis direction) orthogonal to the first direction, the plurality of first LED chips 200-1 and the plurality of second LED chips 200-2 each 3 pitch p3 and a fourth pitch p4. The fourth pitch p4 is greater than the third pitch p3.

Although the details will be described later, basically, the first LED chip 200-1 is transferred to the backplane. On the other hand, the second LED chip 200-2 is used for repairing defective portions. In other words, the LED chip forming substrate 10 includes the second region 120 in which only the repair-specific second LED chips 200-2 are aggregated. Therefore, the number of first LED chips 200-1 formed in the first region 110 is much larger than the number of second LED chips 200-2 formed in the second region 120. FIG. For example, the number of second LED chips 200-2 formed in second region 120 is 0.1% or more and 10% of the number of first LED chips 200-1 formed in first region 110. It is below. Also, the second pitch p2 is, for example, 1 mm or more and 5 mm or less.

Although the detailed structure of the LED chip 200 is omitted, the LED chip 200 may have a vertical electrode structure in which electrodes are arranged in a vertical direction, or a horizontal electrode structure in which electrodes are arranged in a horizontal direction. . The length of one side of the LED chip 200 is, for example, 1 μm or more and 100 μm or less.

[2. Transfer method of LED chip 200]
A method of transferring the LED chip 200 to the backplane will be described with reference to FIGS. 2 to 4C.

[2-1. Cutting process of LED chip forming substrate 10]
FIG. 2 is a schematic diagram illustrating cutting of the LED chip forming substrate 10 in the transfer method of the LED chip 200 according to one embodiment of the present invention.

As shown in FIG. 2 , the LED chip forming substrate 10 is cut so as to be separated into a first transfer substrate 11 and a plurality of second transfer substrates 12 . The first transfer substrate 11 includes a first area 110 . That is, the first transfer substrate 11 is cut so as to include the plurality of first LED chips 200-1 formed in the first region 110. FIG. The second transfer substrate 12 is cut to include one second LED chip 200-2 formed in the second region 120. As shown in FIG. That is, the second transfer board 12 is cut into a plurality of pieces.

The size of the first transfer substrate 11 is substantially the same as the size of the first area 110 . However, if the size of the backplane is smaller than the size of the LED chip forming board 10, the first transfer board 11 may be cut into a plurality of pieces according to the size of the backplane.

Since the second transfer board 12 is evenly cut so as to include one second LED chip 200-2, its size depends on the second pitch p2 and the fourth pitch p4. become a thing. The length of one side of the second transfer substrate 12 is, for example, 1 mm or more and 5 mm or less. If the size of the second transfer board 12 is too small, the second transfer board 12 may be handled (for example, by holding, gripping, or sucking the second transfer board 12 when repairing the defective portion). to do) becomes difficult. Also, if the size of the second transfer board 12 is too large, the number of the first LED chips 200-1 on the first transfer board 11 is reduced, increasing the manufacturing cost. Therefore, the size of the second transfer substrate 12 is preferably within the above range.

Basically, the transfer of the LED chip 200 to the backplane is performed using the first transfer board 11 . The second transfer substrate 12 is used for repairing defective portions.

[2-2. Step of Transferring LED Chip 200 Using First Transfer Board 11]
3A to 3F illustrate the steps of transferring the first LED chip 200-1 using the first transfer board 11 in the method for transferring the LED chip 200 according to one embodiment of the present invention. It is a schematic diagram.

In FIG. 3A, the first blue transfer board 11B on which the first blue LED chip 200B-1 is formed is pressed against the first backplane 30-1, and the first blue LED chip 200B-1 is pressed. The connection member 220 is adhered to the adhesive member 310 of the first backplane 30-1. As the bonding member 310, a material similar to that of the connecting member 220 can be used. Next, the release layer 210 is selectively irradiated with laser light to lift off the first blue LED chip 200B-1. The connection member 220 and the bonding member 310 are bonded together by the lift-off energy of the first blue LED chip 200B-1. good. Note that the selective heating of the connecting member 220 and the bonding member 310 can be performed, for example, by irradiating a laser beam with a wavelength different from that of lift-off.

Similarly, the first green transfer substrate 11G on which the first green LED chip 200G-1 is formed is pressed against the second backplane 30-2 to selectively remove the first green LED chip 200G-1. is lifted off. Similarly, the first red transfer substrate 11R on which the first red LED chip 200R-1 is formed is pressed against the third backplane 30-3 to selectively remove the first red LED chip 200R. -1 is lifted off.

In FIG. 3B, the first blue transfer board 11B is separated from the first backplane 30-1. The selectively lifted-off first blue LED chip 200B-1 is transferred from the first blue transfer board 11B to the first backplane 30-1.

Similarly, the first green transfer board 11G is separated from the second backplane 30-2, and the selectively lifted-off first green LED chip 200G-1 is transferred to the second backplane 30-2. be done. Similarly, the first red transfer board 11R is separated from the third backplane 30-3, and the selectively lifted-off first red LED chip 200R-1 is transferred to the third backplane. be.

In FIG. 3C, the first red transfer substrate 11R to which a part of the first red LED chips 200R-1 has been transferred (that is, the first red transfer substrate 11R having a portion where the first red LED chips 200R-1 are missing) is shown. The red transfer substrate 11R) is pressed against the first backplane 30-1, and the connection member 220 on the first red LED chip 200R-1 is brought into close contact with the adhesive member 310 of the first backplane 30-1. . The first blue LED chip 200B-1 is transferred to the first backplane 30-1, but the first blue LED chip 200B-1 on the first backplane 30-1 is 1 red LED chip 200R-1 can be fitted into the missing part. Therefore, the first red transfer board 11R is pushed to the first backplane 30-1 without being disturbed by the first blue LED chip 200B-1 transferred to the first backplane 30-1. can guess. Next, the release layer 210 is selectively irradiated with laser light to lift off the first red LED chip 200R-1.

Similarly, the first blue transfer substrate 11B on which some of the first blue LED chips 200B-1 are transferred (that is, the first blue LED chip 200B-1 having a missing portion) The transfer substrate 11B) is pressed against the second backplane 30-2 to selectively lift off the first blue LED chip 200B-1. Similarly, the first green transfer board 11G on which some of the first green LED chips 200G-1 are transferred (that is, the first green transfer board 11G having a portion where the first green LED chips 200G-1 are missing) green transfer substrate 11G) is pressed against the third backplane 30-3 to selectively lift off the first green LED chip 200G-1.

In FIG. 3D, the first red transfer board 11R is separated from the first backplane 30-1. The selectively lifted-off first red LED chip 200R-1 is transferred from the first red transfer board 11R to the first backplane 30-1.

Similarly, the first blue transfer board 11B is separated from the second backplane 30-2, and the selectively lifted-off first blue LED chip 200B-1 is transferred to the second backplane 30-2. be done. Similarly, the first green transfer board 11G is separated from the third backplane 30-3, and the selectively lifted-off first green LED chip 200G-1 is transferred to the third backplane. be.

In FIG. 3E, the first green transfer substrate 11G to which some of the first green LED chips 200G-1 are transferred (that is, the first green LED chip 200G-1 having a missing portion) The green transfer board 11G) is pressed against the first backplane 30-1, and the connection member 220 on the first green LED chip 200G-1 is brought into close contact with the adhesive member 310 of the first backplane 30-1. . A first blue LED chip 200B-1 and a first red LED chip 200R-1 are transferred to the first backplane 30-1. The blue LED chip 200B-1 and the first red LED chip 200R-1 can fit into the missing part of the first green LED chip 200G-1. Therefore, the first green transfer substrate 11G can be transferred without being obstructed by the first blue LED chip 200B-1 and the first red LED chip 200R-1 transferred to the first backplane 30-1. It can be pressed against the first backplane 30-1. Next, the release layer 210 is selectively irradiated with laser light to lift off the first green LED chip 200G-1.

Similarly, the first red transfer substrate 11R on which some of the first red LED chips 200R-1 are transferred (that is, the first red LED chip 200R-1 having a missing portion) The transfer board 11R) is pressed against the second backplane 30-2 to selectively lift off the first red LED chip 200R-1. Similarly, the first blue transfer substrate 11B on which some of the first blue LED chips 200B-1 are transferred (that is, the first blue LED chip 200B-1 having a missing portion) blue transfer substrate 11B) is pressed against the third backplane 30-3 to selectively lift off the first blue LED chip 200B-1.

In FIG. 3F, the first green transfer board 11G is separated from the first backplane 30-1. The selectively lifted-off first green LED chip 200G-1 is transferred from the first green transfer board 11G to the first backplane 30-1.

Similarly, the first red transfer substrate 11R is separated from the second backplane 30-2, and the selectively lifted-off first red LED chip 200R-1 is transferred to the second backplane 30-2. be done. Similarly, the first blue transfer board 11B is separated from the third backplane 30-3, and the selectively lifted-off first blue LED chip 200B-1 is transferred to the third backplane. be.

Through the above steps, a plurality of LED chips 200 can be collectively transferred to each of the first backplane 30-1, the second backplane 30-2, and the third backplane 30-3. can. However, various defects occur in transferring the LED chip 200 . In that case, the second transfer board 12 can be used to repair the defective portion.

[2-3. Transfer process of LED chip 200 using second transfer substrate 12]
4A to 4C illustrate steps of transferring the second LED chip 200-2 using the second transfer substrate 12 in the method for transferring the LED chip 200 according to one embodiment of the present invention. It is a schematic diagram.

In FIG. 4A, the defect that the LED chip 200 is missing occurs in the area B1 of the first backplane 30-1. That is, the area B1 lacks the first blue LED chip 200B-1 that should have been transferred.

The defect in the area B1 is not only the defect that the first blue LED chip 200B-1 is not transferred, but also the defect found in the first blue LED chip 200B-1 on the first blue transfer board 11B. A case where the first blue LED chip 200B-1 is selectively not transferred is also included. Also, when a defect is found in the transferred first blue LED chip 200B-1 and the transferred first blue LED chip 200B-1 is removed, the area B1 becomes defective.

In FIG. 4B, the second blue transfer substrate 12B on which the second blue LED chip 200B-2 is formed is pressed against the first backplane 30-1, and the second blue LED chip 200B-2 on the second blue LED chip 200B-2 is pressed against the first backplane 30-1. The connection member 220 is adhered to the adhesive member 310 of the first backplane 30-1. Next, selectively lift off the first blue LED chip 200B-1.

One second blue LED chip 200B-2 is provided on the second blue transfer board 12B. That is, nothing projecting from the support substrate 100 is provided around the second blue LED chip 200B-2. Therefore, the second blue LED chip 200B-2 of the second blue transfer board 12B can fit into the region B1. That is, the first blue LED chip 200B-1, the first green LED chip 200G-1, and the first red LED chip 200R-1 transferred to the first backplane 30-1 interfere with The second blue transfer board 12B can be pressed against the first backplane 30-1 without any movement.

The pressure (or amount of pushing) of the second blue transfer board 12B may be smaller than the pressure (or amount of pushing) of the first blue transfer board 11B. Under such conditions, interference with the LED chips 200 transferred to the backplane 30 can be prevented.

In FIG. 4C, the second blue transfer board 12B is separated from the first backplane 30-1. In region B1, the selectively lifted-off second blue LED chips 200B-2 are transferred from the second blue transfer board 12B to the first backplane 30-1.

Through the steps described above, the second transfer substrate 12 can be used to individually repair defective portions.

The LED chip forming substrate 10 has a first area 110 where the LED chips 200 are arranged with a first pitch p1 for intensive transfer, and a second pitch larger than the first pitch p1. It includes a second region 120 having p2 and in which the LED chip 200 is located. The LED chip forming substrate 10 includes a first transfer substrate 11 capable of collectively transferring the LED chips 200 and a second transfer substrate 12 capable of individually transferring the LED chips 200. and is used separately. In particular, the second transfer substrate 12 can be used for repairing defective portions. That is, in the LED chip forming substrate 10, the LED chips 200 having at least two pitches are formed on one support substrate 100, and the LED chips 200 for repair are not manufactured separately. In addition, since the pitch of the LED chips formed on the LED chip forming substrate 10 is adjusted, it is easy to handle during repair. Therefore, the transfer of LED chips using the LED chip forming substrate 10 can improve the yield of repairing defective portions and suppress the manufacturing cost.

<Second embodiment>
A transfer method of the LED chip 200 different from that of the first embodiment will be described with reference to FIG. Below, when the transfer method of the LED chip 200 which concerns on this embodiment includes the same process as the transfer method of the LED chip 200 which concerns on 1st Embodiment, the description may be abbreviate|omitted.

FIG. 5 is a schematic diagram illustrating a repair process in the method for transferring the LED chip 200 according to one embodiment of the present invention.

In FIG. 5 , in the area C<b>1 of the backplane 30 , the defect that the LED chip 200 is missing occurs. That is, the area C1 lacks the first blue LED chip 200B-1 that should have been transferred. In this case, the thickness of the adhesive member 310A in the area C1 is made larger than the thickness of the adhesive member 310 on which the LED chip 200 is transferred. For example, in the area C1, a new adhesive member 310A may be formed, or the adhesive member 310 may be further coated with solder or the like to form the adhesive member 310A.

In the present embodiment, when the second blue transfer board 12B is pressed against the backplane 30, the second blue transfer board 12B and the back are separated by the difference between the thickness of the adhesive member 310A and the thickness of the adhesive member 310. An extra gap with the plane 30 will be created. Therefore, the second blue transfer substrate 12B can be pressed against the backplane 30 without touching the LED chips 200 that have already been transferred to the backplane 30 . Therefore, the pressure can be concentrated on the second blue LED chip 200B-2 in the area C1, and the second blue LED chip 200B-2 can be reliably transferred to the backplane 30. FIG.

<Third Embodiment>
A transfer method of the LED chip 200 different from the first and second embodiments will be described with reference to FIG. In the following, when the method for transferring the LED chips 200 according to the present embodiment includes the same steps as the method for transferring the LED chips according to the first and second embodiments, the explanation thereof may be omitted. .

In FIG. 6 , in the area D<b>1 of the backplane 30 , the defect that the LED chip 200 is missing occurs. That is, the area D1 lacks the first blue LED chip 200B-1 that should have been transferred. In this case, the thickness of the connection member 220A on the second blue LED chip 200B-2 of the second blue transfer substrate 12B is made larger than the thickness of the connection member 220 on the first blue LED chip 200B-1. do. For example, a connecting member 220A having a thickness different from that of the connecting member 220 may be formed on the second LED chip formed in the second region 120 of the LED chip forming substrate 10, and the connecting member 220 may be further soldered or the like. may be applied to form the connection member 220A.

In this embodiment, when the second blue transfer board 12B is pressed against the backplane 30, the second blue transfer board 12B and the back plane 12B are separated from each other by the difference between the thicknesses of the connection members 220A and the connection members 220A. An extra gap with the plane 30 will be created. Therefore, the second blue transfer board 12B can be pressed against the backplane 30 without touching the LED chips 200 that have already been transferred to the backplane 30 . Therefore, the pressure can be concentrated on the second blue LED chip 200B-2 in the region D1, and the second blue LED chip 200B-2 can be reliably transferred to the backplane 30. FIG.

Each of the embodiments described above as embodiments of the present invention can be implemented in combination as appropriate as long as they do not contradict each other. In addition, based on the display device of each embodiment, a person skilled in the art may add, delete, or change the design of components as appropriate, or add, omit, or change the conditions of a process. As long as it has the gist of the invention, it is included in the scope of the present invention.

Even if there are other effects different from the effects brought about by the aspects of each embodiment described above, those that are obvious from the description of this specification or those that can be easily predicted by those skilled in the art are of course It is understood that it is provided by the present invention.

10: LED chip forming substrate 11: first transfer substrate 11B: first blue transfer substrate 11G: first green transfer substrate 11R: first red transfer substrate 12: second transfer board, 12B: second blue transfer board, 30: backplane, 30-1: first backplane, 30-2: second backplane, 30-3: third backplane, 100: support substrate 110: first region 120: second region 200: LED chip 200-1: first LED chip 200-2: second LED chip 200B: blue LED chip 200B-1: first blue LED chip, 200B-2: second blue LED chip, 200G: green LED chip, 200G-1: first green LED chip, 200R: red LED chip, 200R-1: second 1 red LED chip, 210: peeling layer, 220, 220A: connecting member, 310, 310A: adhesive member

Claims (13)

a first region including a plurality of first LED chips arranged with a first pitch in a first direction;
A second region including a plurality of second LED chips located in a peripheral portion of the first region and arranged with a second pitch larger than the first pitch in the first direction. and including
The LED chip forming substrate, wherein the first LED chip and the second LED chip have the same emission color. 2. The LED chip forming substrate according to claim 1, wherein the number of the plurality of second LED chips is 0.1% or more and 10% or less of the number of the plurality of first LED chips. 2. The LED chip forming substrate according to claim 1, wherein said second pitch is 1 mm or more and 5 mm or less. 4. The LED chip forming substrate according to claim 1, wherein a plurality of said second regions are provided. 5. The LED chip forming substrate according to claim 1, wherein the first LED chip and the second LED chip each have a side length of 1 μm or more and 100 μm or less. a first region including a plurality of first LED chips arranged with a first pitch in a first direction; a second region including a plurality of second LED chips arranged with a second pitch larger than the first pitch; and a second transfer substrate including one of the plurality of second LED chips,
transferring one or more of the plurality of first LED chips to a backplane using the first transfer substrate;
An LED chip transfer method, wherein one of the plurality of second LED chips is transferred to the backplane using the second transfer board. 7. The LED chip transfer method according to claim 6, wherein said first LED chip and said second LED chip have the same emission color. 8. The LED chip transfer method according to claim 6, wherein the number of the plurality of second LED chips is 0.1% or more and 10% or less of the number of the plurality of first LED chips. . 8. The LED chip transfer method according to claim 6, wherein the length of one side of said second transfer substrate is 1 mm or more and 5 mm or less. 10. The LED chip transfer method according to claim 6, wherein a plurality of said second transfer substrates are separated from said LED chip forming substrate. 11. The LED chip transfer method according to claim 6, wherein the length of one side of said first LED chip and said second LED chip is 1 [mu]m or more and 100 [mu]m or less. The transfer using the first transfer board is performed by pressing the first transfer board against the backplane with a first pressure,
The transfer using the second transfer board is performed by pressing the second transfer board against the backplane with a second pressure,
12. The LED chip transfer method according to claim 6, wherein said second pressure is smaller than said first pressure. In the transfer using the first transfer substrate, a first connection member provided on each of one or more of the plurality of first LED chips is adhered to the backplane,
In the transfer using the second transfer substrate, a second connection member provided on one of the plurality of second LED chips is adhered to the backplane,
13. The LED chip transfer method according to claim 6, wherein the thickness of the second connection member is greater than the thickness of the first connection member.

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