KR102288309B1 - Micro LED Display Manufacturing Method - Google Patents

Abstract

The present invention provides a method for manufacturing a microLED display, which enables a defective chip to be easily replaced and shortens a manufacturing process. In accordance with the present invention, a step of transcribing a microLED chip to a midplane is added before the microLED chip is transcribed to a backplane, thereby enabling a user to detect and repair a defective chip on the midplane, so that damage to the backplane, which occurs when a defective chip is replaced on the backplane, can be prevented. In addition, a transparent glass substrate is used as the midplane, thereby allowing the midplane to transmit light emitted by the microLED and perform the function of a protective cover. Therefore, unlike a conventional method where a separate protective layer should be formed when a midplane is joined to the backplane, a manufacturing process of the present invention is simple and the manufacturing time thereof can be shortened.

Description

Micro LED Display Manufacturing Method

The present invention relates to a method for manufacturing a micro LED display, and more particularly, to a method for manufacturing a micro LED display that can easily replace defective chips and shorten the manufacturing process.

In general, a micro light emitting device is an LED having a width and length of 100 μm or less. Recently, a TV using such a micro light emitting device as a light source has been introduced and is attracting attention. It is known that when a micro light emitting device is used as a light source for a display, it requires fewer parts than LCD and has a longer lifespan than OLED, and has advantages of light efficiency and fast response speed.

However, since the micro light emitting device is small in size, there are some difficulties in applying it as a display light source.

1 is a view showing a conventional micro LED display manufacturing process.

Referring to FIG. 1 , in the conventional micro LED display manufacturing process, a micro LED chip 20 manufactured from a wafer 10 is directly transferred to a backplane 30 through a transfer device. Therefore, if a defective chip is generated through inspection after transferring the micro LED chip 20 to the rear substrate 30 , it is necessary to remove the defective chip on the rear substrate 30 and proceed with repair, thereby damaging the rear substrate 30 . may cause In addition, when it is impossible to repair the defective chip, a problem of having to discard the entire rear substrate 30 occurs, so that the yield of the display module is lowered, which causes a problem that leads to an increase in price.

In addition, since the micro LED chip 20 transferred on the rear substrate 30 is transferred, a separate protective film process for protecting the chip 20 is performed or a process for protecting the front surface of the light source unit using a cover glass is performed. The manufacturing process is increased and has a complex disadvantage.

Korean Patent Publication 10-2020-0004688

The problem to be solved by the present invention is to transfer a micro LED chip to an intermediate substrate before transferring it to the rear substrate to replace the defective chip, thereby providing a method for manufacturing a micro LED display that can easily replace defective chips and shorten the manufacturing process. is in

In order to solve the above problems, the method for manufacturing a micro LED display of the present invention includes transferring a micro LED chip formed on a growth substrate so as to be disposed on the first surface of the intermediate substrate, and inspecting the micro LED chip transferred to the intermediate substrate. step, repairing the defective chip selected through the inspection, forming a wiring part on the micro LED chip, and attaching a rear substrate on the wiring part.

The transferring of the micro LED chip to the intermediate substrate may further include forming a transparent adhesive layer on the intermediate substrate.

The step of repairing the defective chip includes: determining the position of the selected defective chip; individually or simultaneously removing the determined defective chip; and individually or simultaneously transferring the defective chip to the position where the defective chip is removed. It may include further steps.

In the step of removing the defective chip, the defective chip may be removed using laser ablation, an electrostatic chuck, or a magnetic chuck.

The electrostatic chuck may include a cover substrate, a dielectric layer formed on the cover substrate, a carrier substrate formed on the dielectric layer, and electrodes disposed to face each other around the dielectric layer.

The electrodes may be respectively formed at positions corresponding to the micro LED chips disposed on the intermediate substrate.

The step of removing the defective chip using the electrostatic chuck includes: placing the electrostatic chuck on the micro LED chip; inducing an electrostatic force by applying a voltage to an electrode corresponding to the defective chip; The method may include attaching and removing the defective chip to the electrostatic chuck by electrostatic force.

The step of forming the wiring part is formed on the first surface of the intermediate substrate, forming a first passivation layer to cover all of the micro LED chip, and the micro LED chip and electrical power on the first passivation layer forming a first wiring layer so as to be connected to It may include forming a wiring layer.

The second wiring layer is formed to be exposed on the second passivation layer, is formed to be exposed on the positive contact electrode and the second passivation layer that are individually connected to the rear substrate, and is separate or common to the rear substrate It may include a negative contact electrode connected to.

In the step of attaching the rear substrate on the wiring part, the rear substrate may be attached to be electrically connected to the positive contact electrode and the negative contact electrode.

The intermediate substrate may be formed of a transparent substrate so that the micro LED light is transmitted.

The first passivation layer may include a black matrix.

Before transferring the micro LED chip to the intermediate substrate, the method may further include forming a via hole in the intermediate substrate and forming a first wiring layer in the via hole.

The first wiring layer may further include a positive contact electrode formed on a first surface of the intermediate substrate and a second surface opposite to the first surface, and a negative contact electrode formed on the first surface and the second surface of the intermediate substrate. may include

The step of forming the wiring part is formed on the first surface of the intermediate substrate, forming a first passivation layer to cover all of the micro LED chip, is formed on the first passivation layer, the micro LED forming a second wiring layer such that a chip is electrically connected to the positive and negative contact electrodes formed on the first surface, and forming a second passivation layer on the first and second wiring layers may include the step of

In the step of attaching the rear substrate to the wiring part, the rear substrate may be attached to be electrically connected to the positive and negative contact electrodes formed on the second surface.

The intermediate substrate may be formed of any one of a transparent substrate, an opaque substrate, a rigid substrate, or a flexible substrate.

After attaching the rear substrate to the wiring unit, the method may further include forming an underfill resin between the wiring unit and the rear substrate.

According to the present invention, it is possible to detect and repair a defective chip on the intermediate substrate by adding the step of transferring the micro LED chip to the intermediate substrate before transferring it to the backplane. Accordingly, since it is possible to prevent damage to the rear substrate occurring when a defective chip is replaced in the rear substrate, it is possible to improve the yield of display manufacturing.

In addition, by using a transparent glass substrate as an intermediate substrate, it is not necessary to perform a separate protective film process when combining the intermediate substrate with the rear substrate as in the prior art, because it can transmit light emitted from the micro LED and simultaneously perform a protective cover function. . Accordingly, the manufacturing process is simple and the manufacturing time is shortened.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a view showing a conventional micro LED display manufacturing process.
2 is a view showing a micro LED chip disposed on an intermediate substrate of the present invention.
3 is a view showing a method of removing a defective chip using the electrostatic chuck of the present invention.
4 to 8 are diagrams illustrating a wiring part manufacturing process according to a back light emission method of a micro LED display.
9 to 14 are views showing a wiring part manufacturing process according to the front light emitting method of the micro LED display.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

While the present invention is susceptible to various modifications and variations, specific embodiments thereof are illustrated and shown in the drawings and will be described in detail hereinafter. However, it is not intended to limit the invention to the particular form disclosed, but rather the invention includes all modifications, equivalents and substitutions consistent with the spirit of the invention as defined by the claims.

It will be understood that when an element, such as a layer, region, or substrate, is referred to as being “on” another component, it may be directly on the other element or intervening elements in between. .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and/or regions, such elements, components, regions, layers and/or regions are not It will be understood that they should not be limited by these terms.

2 to 14 are views showing a manufacturing process for manufacturing the micro LED display of the present invention.

2 to 14 , in the manufacturing process of manufacturing the micro LED display according to the present invention, the micro LED chip 200 formed on the growth substrate is transferred to be disposed on the first surface 101 of the intermediate substrate 100 . step, inspecting the micro LED chip 200 transferred to the intermediate substrate 100, repairing the defective chip selected through the inspection, forming the wiring unit 500 on the micro LED chip 200 and attaching the rear substrate 600 on the wiring unit 500 .

First, FIG. 2 is a view showing a micro LED chip disposed on an intermediate substrate of the present invention.

Referring to FIG. 2 , the micro LED chip 200 is transferred and disposed on the intermediate substrate 100 . In this case, the micro LED chip 200 may be disposed on the first surface 101 in the upper direction of the intermediate substrate 100 . Here, the intermediate substrate 100 may be a substrate formed of any one of silicon (Si), glass, ceramic, flexible substrate, PET, or PC. That is, various substrates such as a transparent substrate, an opaque substrate, a rigid substrate, or a flexible substrate may be used. However, in the case of the front light emitting method in which the micro LED display emits light in the direction of the first surface 101 of the intermediate substrate 100, various substrates such as a transparent substrate, an opaque substrate, a rigid substrate, or a flexible substrate may be used, but the micro LED display In the case of the rear light emitting method in which the intermediate substrate 100 emits light in the direction of the second surface 102, it is preferable to use a transparent substrate such as a glass or quartz substrate.

The micro LED chip 200 is a light emitting diode chip used to reproduce colors such as RGB (RED, Green, Blue), and may be manufactured on a growth substrate.

For example, the micro LED chip 200 may have a form in which a first semiconductor layer, an active layer, and a second semiconductor layer are stacked. Also, the first semiconductor layer may be formed of a p-type semiconductor layer doped with a p-type dopant, and the second semiconductor layer may be formed of an n-type semiconductor layer doped with an n-type dopant. However, the first semiconductor layer may be formed of an n-type semiconductor layer and the second semiconductor layer may be formed of a p-type semiconductor layer. The active layer is a region where electrons and holes recombine, and may be formed in a single quantum well structure or a multi quantum well (MQW) structure, and may include a quantum wire structure or a quantum dot structure. may be

In addition, the micro LED chip 200 may include a first chip electrode 210 and a second chip electrode 220 connected to the semiconductor layers and electrically connected to the rear substrate 600 . For example, the first chip electrode 210 may function as a positive electrode, and the second chip electrode 220 may function as a negative electrode. Since the first chip electrode 210 and the second chip electrode 220 are formed to protrude from the micro LED chip 200 , when the micro LED chip 200 is attached to the intermediate substrate 100 , the first chip electrode 210 is ) and the second chip electrode 220 may be disposed to be positioned on the opposite side to the intermediate substrate 100 .

The intermediate substrate 100 and the micro LED chip 200 may be bonded to each other by the transparent adhesive layer 300 . That is, before the step of transferring the micro LED chip 200 to the intermediate substrate 100 , the method may further include a step of forming the transparent adhesive layer 300 on the intermediate substrate 100 .

The transparent adhesive layer 300 may be patterned on the intermediate substrate 100 through a photolithography process. For example, the transparent adhesive layer 300 is deposited on the first surface 101 of the intermediate substrate 100 , and a portion where the micro LED chip 200 is not disposed may be removed through a plasma etching process. The transparent adhesive layer 300 may be formed of any one material of PSA, silicone, acrylic, or epoxy, and while curing in response to heat and UV light, the intermediate substrate 100 and the micro LED chip 200 may be adhered to each other. Any material can be used as long as it exists.

At this time, the intermediate substrate 100 and the micro LED chip 200 are adhered by the transparent adhesive layer 300 , and may be adhered using a predetermined adhesive force to separate the selected defective chips from the intermediate substrate 100 . . Here, the adhesive force of the transparent adhesive layer 300 can be adjusted by controlling the temperature or UV light.

After the micro LED chip 200 is transferred onto the intermediate substrate 100 , it is possible to determine whether the chip is defective by measuring the micro LED chip 200 using a micro PL or EL measurement method. The selected bad chips may be individually or simultaneously removed after determining the positions of the bad chips. In addition, good chips may be individually or simultaneously transferred to positions where the bad chips are removed from the intermediate substrate 100 .

As a method of removing such a defective chip, it may be removed by using laser ablation, an electrostatic chuck, or a magnetic chuck. Here, the electrostatic chuck is a method of removing defective chips using electrostatic force, and the magnetic chuck is a method of removing defective chips using the magnetic force of a permanent magnet. However, when a magnetic chuck is used, the defective chip can be attached to the magnetic chuck by depositing Ni or Fe on the chip electrode of the micro LED chip 200 .

3 is a view showing a method of removing a defective chip using the electrostatic chuck of the present invention.

Referring to FIG. 3 , in the method of using the electrostatic chuck 400 , a defective chip is attached to the electrostatic chuck 400 using electrostatic force generated by applying a voltage to the electrode 440 included in the electrostatic chuck 400 . way to remove it. The electrostatic chuck 400 may be classified into a low-resistance chuck and a high-resistance chuck according to a specific resistance value of a dielectric material, but the electrostatic chuck 400 suitable for the embodiment of the present invention is not limited thereto. However, since the electrostatic chuck 400 according to the embodiment of the present invention has to attach the micro LED chip 200 using the induced electrostatic force, a low resistance using the Johnson-Rahbeck effect in which a large electrostatic force is induced. An electrostatic chuck may be used.

The electrostatic chuck 400 is disposed to face each other with respect to the cover substrate 410 , the dielectric layer 420 formed on the cover substrate 410 , the carrier substrate 430 formed on the dielectric layer 420 , and the dielectric layer 420 . electrode 440 may be included. Here, the electrode 440 is preferably formed to be disposed at a position corresponding to the micro LED chip 200 disposed on the intermediate substrate 100 .

First, the electrostatic chuck 400 is positioned on the micro LED chip 200 to be spaced apart from the micro LED chip 200 disposed on the intermediate substrate 100 by a predetermined distance. When the electrostatic chuck 400 is disposed on the micro LED chip 200, an electrostatic force is induced by applying a voltage to the electrode 440 formed at a position corresponding to the defective chip. Here, the location of the defective chip may be determined by linking mapping information including location information of the micro LED chip 200 to the electrostatic chuck 400 .

When an electrostatic force is induced in the corresponding electrode 440 , the defective chip may be attached to and removed from the electrostatic chuck 400 by the induced electrostatic force. Therefore, it is possible to simply remove the defective chip without damage to the intermediate substrate 100 and the surrounding micro LED chip 200 . At this time, the voltage applied to remove the defective chip may be individually applied to the electrodes 440 corresponding to each defective chip, or may be simultaneously applied to the entire electrode 440 corresponding to all of the defective chips.

After all the bad chips are removed, all the good chips are transferred to the positions of the removed bad chips, and the transparent adhesive layer 300 is permanently applied through heat or UV curing so that the micro LED chip 200 is fixed to the intermediate substrate 100 . harden

After removing and repairing all defective chips on the intermediate substrate 100 , the wiring unit 500 may be formed on the micro LED chip 200 .

The wiring unit 500 may have different embodiments according to the light emission method of the micro LED display. That is, the wiring unit 500 may be formed in a different shape in the back light emission method and the front light emission method of the micro LED display.

First, a manufacturing process of the wiring unit 500 according to the back light emission method of the micro LED display will be described.

4 to 8 are diagrams illustrating a wiring part manufacturing process according to a back light emission method of a micro LED display.

Here, the wiring unit 500 may include a first passivation layer 510 , a first wiring layer 520 , a second passivation layer 530 , and a second wiring layer 540 .

First, referring to FIG. 4 , a first passivation layer 510 may be formed on the intermediate substrate 100 . At this time, the first passivation layer 510 is preferably formed to surround all of the micro LED chip 200 disposed on the intermediate substrate (100). The first passivation layer 510 may be formed of an insulating material, for example, acrylic, poly(methyl methacrylate) (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy, polyester, etc. can be formed with In addition, preferably, in the case of the first passivation layer 510, it is possible to prevent the colors emitted through the intermediate substrate 100 from being mixed by using a material capable of absorbing light, for example, a black matrix. there is.

Referring to FIG. 5 , a first wiring layer 520 is formed on the first passivation layer 510 . The first wiring layer 520 may include a conductive material and may be formed to be connected to the micro LED chip 200 . In more detail, the first wiring layer 520 may be formed to be electrically connected to the first chip electrode 210 and the second chip electrode 220 of the micro LED chip 200 , respectively. That is, in each micro LED chip 200 , the first wiring layer 520 is a first wiring layer 520 connected to the first chip electrode 210 functioning as a positive electrode, and a second wiring layer 520 functioning as a negative electrode. It may be formed to be divided into the first wiring layer 520 connected to the chip electrode 220 .

Referring to FIG. 6 , a second passivation layer 530 is formed on the first passivation layer 510 and the first wiring layer 520 . Here, the second passivation layer 530 may be formed to cover all of the first wiring layer 520 . The material of the second passivation layer 530 may be formed of, for example, acrylic, poly(methyl methacrylate) (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy, polyester, or the like. .

Referring to FIG. 7 , a second wiring layer 540 is formed on the second passivation layer 530 . The second wiring layer 540 may include a conductive material and may be formed to be electrically connected to the first wiring layer 520 . For example, the second wiring layer 540 is electrically connected to the first wiring layer 520 and functions as a positive contact electrode 541 on the upper surface of the second passivation layer 530 . It may be formed to be divided into a second wiring layer 540 that is electrically connected to the first wiring layer 520 and functions as a negative contact electrode 542 on the upper surface of the second passivation layer 530 . That is, the positive contact electrode 541 electrically connected to the first chip electrode 210 and the negative contact electrode 542 electrically connected to the second chip electrode 220 are exposed to the second passivation layer 530 . can be formed.

Here, the negative contact electrode 542 of the second wiring layer 540 is connected to the ground (VSS) terminal of the rear substrate 600 , and each of the negative contact electrodes 542 of the micro LED chip 200 is individually It may be formed to be connected, or may be formed to be connected to a common electrode integrated into one.

Referring to FIG. 8 , the rear substrate 600 is attached to the wiring unit 500 . The back substrate 600 may include a thin film transistor (TFT) or a PCB as a backplane. Here, the thin film transistor may include a circuit part having a gate electrode, an active layer electrically insulated from the gate electrode by a gate insulating layer, and a source electrode and a drain electrode electrically connected to the active layer. In addition, connection electrodes 610 and 620 connected to the thin film transistor TFT may be formed on the rear substrate 600 .

The rear substrate 600 is attached to be in contact with the wiring unit 500, and the exposed positive contact electrode 541 and the negative contact electrode 542 are respectively connected to the connection electrodes 610 and 620 formed on the rear substrate 600. It can be attached so as to be in contact with each other through bonding. For example, the positive contact electrode 541 connected to the first chip electrode 210 of the micro LED chip 200 may be connected to the connection electrodes 610 of the rear substrate 600 , and the second chip electrode 220 . ) and the negative contact electrode 542 may be connected to the ground electrodes 620 of the rear substrate 600 . In addition, as a method of attaching the rear substrate 600 and the wiring unit 500 , it may be attached using a metal solder bump, a stud bump, or a vertical conductive film.

After the rear substrate 600 is attached to the wiring unit 500 , an underfill resin 700 process may be performed between the wiring unit 500 and the rear substrate 600 if necessary. This is to protect the module by filling in the empty space of the final micro LED display module.

As shown in FIG. 8, by forming the wiring part 500 according to the back light emission method of the micro LED display, and attaching the wiring part 500 and the rear substrate 600, the light emitted from the micro LED is formed of a glass substrate. Light may be emitted through the intermediate substrate 100 . In addition, by using a transparent glass substrate as the intermediate substrate 100, it is possible to simultaneously perform a protective cover function as well as transmit the light emitted from the micro LED. There is no need to perform a separate protective film process. Accordingly, the manufacturing process is simple and the manufacturing time is shortened.

9 to 14 are views showing a wiring part manufacturing process according to the front light emitting method of the micro LED display.

First, referring to FIG. 9 , a via hole 103 is formed in the intermediate substrate 100 . Here, since the micro LED display uses a front light emitting method in which light is emitted in the opposite direction of the intermediate substrate 100 , the intermediate substrate 100 is a transparent substrate, an opaque substrate, a rigid substrate or a flexible substrate, such as various substrates. this can be used

The via hole 103 may be formed to penetrate from the first surface 101 of the intermediate substrate 100 to the second surface 102 opposite to the first surface 101 . In addition, the via hole 103 may be formed around the first chip electrode 210 and the second chip electrode 220 of the micro LED chip 200 . For example, the via hole 103 is formed to correspond to the first chip electrode 210 and the second chip electrode 220 , respectively, and is formed at a position adjacent to the first chip electrode 210 and the second chip electrode 220 . can be

After the via hole 103 is formed, a first wiring layer 520 is formed in the via hole 103 . The first wiring layer 520 may be formed in the via hole 103 and include positive contact electrodes 521 and 523 and negative contact electrodes 522 and 524 . That is, the first wiring layer 520 is a positive contact electrode on the first surface 101 and the second surface 102 of the intermediate substrate 100 so as to be connected to the first wiring layer 520 formed in the via hole 103 , respectively. (521, 523) and negative contact electrodes (522, 524) may be formed.

Here, the positive contact electrode 521 and the negative contact electrode 522 formed on the first surface 101 are connected to the micro LED chip 200 , and the positive contact electrode formed on the second surface 102 . 523 and the negative contact electrode 524 may be exposed from the intermediate substrate 100 to be connected to the rear substrate 600 . For reference, FIG. 9 is a diagram illustrating a case where the negative contact electrode 524 formed on the second surface 102 is a common electrode.

Referring to FIG. 10 , the micro LED chip 200 is transferred and disposed on the intermediate substrate 100 on which the via hole 103 and the first wiring layer 520 are formed. The micro LED chip 200 may be disposed on the intermediate substrate 100 in the same way as the back light emission method. At this time, the micro LED chip 200 is disposed so as to be positioned between the positive contact electrode 521 and the negative contact electrode 522 formed on the first surface 101 of the intermediate substrate 100, respectively, the first chip The electrode 210 and the second chip electrode 220 may be disposed to be opposite to the intermediate substrate 100 .

After the micro LED chip 200 is transferred onto the intermediate substrate 100 , the defective chip removal and repair process may be performed in the same manner as described above.

Referring to FIG. 11 , a first passivation layer 510 is formed on the intermediate substrate 100 . In this case, the first passivation layer 510 includes the micro LED chip 200 disposed on the first surface 101 of the intermediate substrate 100 , the positive contact electrode 521 of the first wiring layer 520 and the negative It may be formed to cover all of the contact electrodes 522 .

Referring to FIG. 12 , a second wiring layer 540 is formed on the first passivation layer 510 . Here, the second wiring layer 540 is formed on the upper surface of the first passivation layer 510 , and may be formed to be electrically connected to the micro LED chip 200 and the first wiring layer 520 . For example, the first chip electrode 210 may be electrically connected to the positive contact electrode 521 formed on the first surface 101 of the intermediate substrate 100 by the second wiring layer 540 , and the second The chip electrode 220 may be electrically connected to the negative contact electrode 521 formed on the first surface 101 of the intermediate substrate 100 .

Referring to FIG. 13 , a second passivation layer 530 is formed on the second wiring layer 540 . Here, the second passivation layer 530 may be formed to completely cover the second wiring layer 540 . Accordingly, the manufacturing process of the wiring unit 500 according to the front light emitting method is completed.

As described above, in the manufacturing process of the wiring unit 500, the back light emitting method is in the order of the first passivation layer 510, the first wiring layer 520, the second passivation layer 530, and the second wiring layer 540. Although the manufacturing process of the wiring unit 500 by have a difference

Referring to FIG. 14 , the rear substrate 600 is attached to the wiring unit 500 . That is, the positive contact electrode 523 and the negative contact electrode 524 formed to be exposed on the second surface 102 of the intermediate substrate 100 are bonded to the connection electrodes 610 and 620 formed on the rear substrate 600 . It can be attached to contact each other through. For example, the positive contact electrode 523 connected to the first chip electrode 210 of the micro LED chip 200 may be connected to the connection electrodes 610 of the rear substrate 600 , and the second chip electrode 220 . ) and the negative contact electrode 524 may be connected to the ground electrodes 620 of the rear substrate 600 as a common electrode. In addition, as a method of attaching the rear substrate 600 and the wiring unit 500 , it may be attached using a metal solder bump, a stud bump, or a vertical conductive film.

After the rear substrate 600 is attached on the wiring unit 500, it is placed between the wiring unit 500 and the rear substrate 600 to protect the module by filling the empty space of the micro LED display module as in the back light emitting method. An underfill resin 700 process may be performed.

As shown in FIG. 14, by forming the wiring part 500 according to the front light emission method of the micro LED display and attaching the wiring part 500 and the rear substrate 600, the light emitted from the micro LED is an intermediate substrate. The light may be emitted in a direction opposite to (100).

As described above, before transferring the micro LED chip 200 to the backplane 600 , the step of transferring the micro LED chip 200 to the intermediate substrate 100 is added to detect and repair the defective chip on the intermediate substrate 100 . can Accordingly, since it is possible to prevent damage to the rear substrate 600 that occurs when a defective chip is replaced in the rear substrate 600 , the yield of display manufacturing can be improved. In addition, by using a transparent glass substrate as the intermediate substrate 100, it is possible to simultaneously perform a protective cover function as well as light transmission from the micro LED. There is no need to perform a separate protective film process. Accordingly, the manufacturing process is simple and the manufacturing time is shortened.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

100: intermediate substrate 200: micro LED chip
210: first chip electrode 220: second chip electrode
300: transparent adhesive layer 400: electrostatic chuck
410: cover substrate 420: dielectric layer
430: carrier substrate 440: electrode
500: wiring unit 510: first passivation layer
520: first wiring layer 530: second passivation layer
540: second wiring layer 600: rear substrate
700: under essential resin

Claims (18)

transferring the micro LED chip formed on the growth substrate to be disposed on the first surface of the intermediate substrate;
inspecting the micro LED chip transferred to the intermediate substrate;
repairing the defective chips selected through the inspection on the intermediate substrate and replacing them with good micro LED chips;
fixing the micro LED chip including the micro LED chip of the good quality to the intermediate substrate;
forming a wiring part on the micro LED chip fixed to the intermediate substrate; and
and electrically connecting a rear substrate functioning as a backplane on the wiring unit,
The light emitted from the micro LED chip is emitted through the intermediate substrate or is emitted in the opposite direction of the intermediate substrate. The method of claim 1, wherein the transferring of the micro LED chip to the intermediate substrate comprises:
Micro LED display manufacturing method further comprising the step of forming a transparent adhesive layer on the intermediate substrate. The method of claim 1, wherein repairing the defective chip comprises:
determining the location of the selected defective chip;
individually or simultaneously removing the identified defective chips; and
The micro LED display manufacturing method further comprising the step of individually or simultaneously transferring the good chip to the position where the bad chip is removed. The method of claim 3, wherein in the step of removing the defective chip,
The method for manufacturing a micro LED display wherein the defective chip is removed using laser ablation, an electrostatic chuck, or a magnetic chuck. The method of claim 4, wherein the electrostatic chuck,
cover substrate;
a dielectric layer formed on the cover substrate;
a carrier substrate formed on the dielectric layer; and
A micro LED display manufacturing method comprising electrodes disposed to face each other with respect to the dielectric layer. 6. The method of claim 5,
The electrode is a micro LED display manufacturing method which is formed at a position corresponding to the micro LED chip disposed on the intermediate substrate, respectively. The method of claim 6 , wherein removing the defective chip using the electrostatic chuck comprises:
positioning the electrostatic chuck on the micro LED chip;
inducing an electrostatic force by applying a voltage to an electrode corresponding to the defective chip; and
and attaching and removing the defective chip to the electrostatic chuck by the induced electrostatic force. The method of claim 1, wherein the forming of the wiring part comprises:
forming a first passivation layer formed on the first surface of the intermediate substrate to cover all of the micro LED chip;
forming a first wiring layer on the first passivation layer to be electrically connected to the micro LED chip;
forming a second passivation layer on the first passivation layer and the first wiring layer; and
and forming a second wiring layer on the second passivation layer to be electrically connected to the first wiring layer. The method of claim 8, wherein the second wiring layer comprises:
a positive contact electrode formed to be exposed on the second passivation layer and separately connected to the rear substrate; and
and a negative contact electrode formed to be exposed on the second passivation layer and connected individually or in common to the rear substrate. 10. The method of claim 9, wherein in the step of attaching the rear substrate on the wiring portion,
The method for manufacturing a micro LED display wherein the rear substrate is attached to be electrically connected to the positive contact electrode and the negative contact electrode. 9. The method of claim 8,
The intermediate substrate is a micro LED display manufacturing method that is formed of a transparent substrate so that the micro LED light is transmitted. 9. The method of claim 8,
The first passivation layer is a micro LED display manufacturing method comprising a black matrix (black matrix). The method of claim 1, wherein before transferring the micro LED chip to the intermediate substrate,
forming a via hole in the intermediate substrate; and
The micro LED display manufacturing method further comprising the step of forming a first wiring layer in the via hole. The method of claim 13, wherein the first wiring layer,
a positive contact electrode formed on a first surface of the intermediate substrate and a second surface opposite to the first surface; and
The micro LED display manufacturing method further comprising a negative contact electrode formed on the first surface and the second surface. The method of claim 14, wherein the forming of the wiring part comprises:
forming a first passivation layer formed on the first surface of the intermediate substrate to cover all of the micro LED chip;
forming a second wiring layer formed on the first passivation layer so that the micro LED chip is electrically connected to the positive contact electrode and the negative contact electrode formed on the first surface; and
A method of manufacturing a micro LED display comprising forming a second passivation layer on the first passivation layer and the second wiring layer. 15. The method of claim 14, wherein in the step of attaching the rear substrate on the wiring portion,
The method of claim 1, wherein the rear substrate is attached to be electrically connected to the positive and negative contact electrodes formed on the second surface. 14. The method of claim 13,
The intermediate substrate is a transparent substrate, an opaque substrate, a method of manufacturing a micro LED display that is formed of any one of a rigid substrate or a flexible substrate. According to claim 1, After attaching the rear substrate on the wiring portion,
The micro LED display manufacturing method further comprising the step of forming an underfill resin between the wiring part and the rear substrate.

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