KR102387811B1 - Substrate chuck for self assembly of semiconductor light emitting device - Google Patents

Abstract

The present invention provides a substrate chuck for seating a semiconductor light emitting device dispersed in a fluid at a predetermined position on a substrate. The substrate chuck includes a substrate support portion configured to support a substrate having an assembly electrode, a vertical movement portion for lowering the substrate so that one surface of the substrate is in contact with a fluid in a state in which the substrate is supported, and the semiconductor light emitting devices are the magnets. In order to be seated at a preset position of the substrate in the process of moving by the position change, the electrode connection part for generating an electric field by applying power to the assembly electrode and the substrate are directed upward or downward so that the substrate support is rotated shaft and a rotating part rotating around

Description

SUBSTRATE CHUCK FOR SELF ASSEMBLY OF SEMICONDUCTOR LIGHT EMITTING DEVICE

The present invention relates to a method of manufacturing a display device, and more particularly, to a substrate chuck for self-assembly of a micro LED.

Recently, liquid crystal displays (LCD), organic light emitting diode (OLED) displays, and micro LED displays are competing to implement a large-area display in the field of display technology.

On the other hand, when a semiconductor light emitting device (micro LED (uLED)) having a diameter or cross-sectional area of 100 microns or less is used for a display, very high efficiency can be provided because the display does not absorb light using a polarizing plate or the like. However, since a large display requires millions of semiconductor light emitting devices, it is difficult to transfer the devices compared to other technologies.

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Techniques currently being developed as a transfer process include pick & place, laser lift-off (LLO), or self-assembly. Among them, the self-assembly method is a method in which the semiconductor light emitting device finds its own position in a fluid, and is the most advantageous method for realizing a large-screen display device.

Recently, although a micro LED structure suitable for self-assembly has been proposed in US Patent No. 9,825,202, research on a technology for manufacturing a display through self-assembly of the micro LED is still insufficient. Accordingly, the present invention proposes a new type of manufacturing apparatus in which the micro LED can be self-assembled.

One object of the present invention is to provide a new manufacturing process having high reliability in a large-screen display using a micro-sized semiconductor light emitting device.

Another object of the present invention is to provide a substrate chuck capable of removing air bubbles formed between a substrate and a fluid when a semiconductor light emitting device is self-assembled into a temporary substrate or a wiring substrate.

Another object of the present invention is to provide a substrate chuck capable of preventing a pre-assembled semiconductor light emitting device from being separated from the substrate when the substrate is separated from the fluid after self-assembly.

Another object of the present invention is to provide a substrate chuck capable of preventing the substrate from being damaged due to the buoyancy applied to the substrate during self-assembly.

In order to achieve the above object, the present invention provides a substrate chuck for seating a semiconductor light emitting device dispersed in a fluid at a predetermined position on a substrate. The substrate chuck includes a substrate support portion configured to support a substrate having an assembly electrode, a vertical movement portion for lowering the substrate so that one surface of the substrate is in contact with a fluid in a state in which the substrate is supported, and the semiconductor light emitting devices are the magnets. In order to be seated at a preset position of the substrate in the process of moving by the position change, the electrode connection part for generating an electric field by applying power to the assembly electrode and the substrate are directed upward or downward so that the substrate support is rotated shaft and a rotating part rotating around

In one embodiment, the rotation shaft may be located at the end of the substrate support.

In an embodiment, the substrate support part includes first and second frames and sidewall parts for fixing the substrate in both directions, and a fixing part for fixing the first and second frames, and the rotation shaft is the fixing part. It may be disposed at one end of the side wall portion of the

In an embodiment, it is disposed on the fixing unit and includes a frame moving unit for vertically moving the second frame, wherein the frame moving unit presses the first and second frames to the substrate while the substrate is loaded. To do so, at least one of the first and second frames may be vertically moved.

In an embodiment, at least one of the first and second frames may be formed with a protrusion for guiding an alignment position of the substrate.

In an embodiment, each of the first and second frames may have a bottom portion in contact with the substrate and a center portion of the bottom portion, and may include a hole exposing one surface of the substrate to the outside.

In an embodiment, in a state in which the first and second frames press the substrate, the bottom portion provided in the second frame may be formed to contact the entire edge of one of both surfaces of the substrate.

In an embodiment, the method further includes a sealing part disposed on a bottom part of the first frame, wherein in a state in which the first and second frames press the substrate, the sealing part is the other of both surfaces of the substrate. It may be formed so as to be in contact with the entire edge of the surface.

In an embodiment, the present invention may further include an auxiliary clamp for fixing at least one of the second frame and the substrate while the second frame presses the substrate.

In one embodiment, the displacement sensor is disposed on the fixing unit, the displacement sensor is configured to measure a distance from the measurement target object, and the sensor transfer unit is disposed on the side wall of the fixing unit and horizontally moves the displacement sensor with respect to the substrate. may include

According to the present invention having the above configuration, in a display device in which individual pixels are formed of micro light emitting diodes, a large number of semiconductor light emitting devices can be assembled at once.

As described above, according to the present invention, it is possible to pixelate a semiconductor light emitting device in a large amount on a small-sized wafer and then transfer it to a large-area substrate. Through this, it is possible to manufacture a large-area display device at a low cost.

In addition, according to the present invention, it is possible to realize low-cost, high-efficiency, and high-speed transfer regardless of the size, number, or transfer area of parts by simultaneously transferring the semiconductor light emitting device to the correct position using a magnetic field and an electric field in a solution. .

Furthermore, since the assembly is performed by an electric field, selective assembly is possible through selective electrical application without a separate additional device or process. In addition, by arranging the assembly substrate on the upper side of the chamber, loading and unloading of the substrate can be facilitated, loading and unloading can be facilitated, and non-specific binding of the semiconductor light emitting device can be prevented.

In the present invention, when the substrate and the fluid are brought into contact, the air bubbles are pushed to the edge of the substrate and removed by allowing the substrate and the fluid to contact at an angle. Through this, the present invention prevents the self-assembly yield from being lowered due to air bubbles.

In addition, the present invention minimizes the surface energy acting between the substrate and the fluid by obliquely detaching the substrate from the fluid after the self-assembly is completed. Through this, the present invention prevents the pre-assembled semiconductor light emitting device from being separated from the substrate.

In addition, the present invention prevents the damage of the substrate due to the buoyancy force acting on the substrate by strongly fixing the entire edge of the substrate during self-assembly.

1 is a conceptual diagram illustrating an embodiment of a display device using a semiconductor light emitting device of the present invention.
FIG. 2 is a partially enlarged view of a portion A of the display device of FIG. 1 .
FIG. 3 is an enlarged view of the semiconductor light emitting device of FIG. 2 .
4 is an enlarged view illustrating another embodiment of the semiconductor light emitting device of FIG. 2 .
5A to 5E are conceptual views for explaining a new process of manufacturing the above-described semiconductor light emitting device.
6 is a conceptual diagram illustrating an example of an apparatus for self-assembly of a semiconductor light emitting device according to the present invention.
7 is a block diagram of the self-assembly apparatus of FIG. 6 .
8A to 8E are conceptual views illustrating a process of self-assembling a semiconductor light emitting device using the self-assembly apparatus of FIG. 6 .
9 is a conceptual diagram illustrating the semiconductor light emitting device of FIGS. 8A to 8E .
10 is a flowchart illustrating a self-assembly method according to the present invention.
11 is a conceptual diagram illustrating a first state of the substrate chuck.
12 is a conceptual diagram illustrating a second state of the substrate chuck.
13 is a plan view of a first frame provided in the substrate chuck.
14 is a conceptual diagram illustrating a state in which an assembly substrate is loaded in a substrate chuck.
15 is a perspective view of a magnetic field forming unit according to an embodiment of the present invention.
16 is a side view of a magnetic field forming unit according to an embodiment of the present invention.
17 is a lower side view of another magnetic field forming unit according to an embodiment of the present invention.
18 is a conceptual diagram illustrating the trajectories of magnets provided in the magnetic field forming unit according to the present invention.
19 is a conceptual diagram illustrating a state of supplying a semiconductor light emitting device.
20 is a plan view of an assembly chamber according to an embodiment of the present invention.
Fig. 21 is a cross-sectional view taken along line A-A' in Fig. 20;
22 and 23 are conceptual views illustrating movement of a gate provided in an assembly chamber according to an embodiment of the present invention.
24 is a conceptual diagram illustrating a substrate bending phenomenon that occurs during self-assembly.
25 is a conceptual diagram illustrating a method for correcting warpage of a substrate.
26 to 29 are perspective views of a substrate chuck according to an embodiment of the present invention.
30 is a perspective view illustrating a second frame and a frame transfer unit according to an embodiment of the present invention.
31 is a side view illustrating a second frame and a frame transfer unit according to an embodiment of the present invention.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numbers regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical spirit disclosed herein by the accompanying drawings.

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

The display device described in this specification includes a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, and a slate PC. , Tablet PCs, Ultra Books, Digital TVs, Digital Signage, Head Mounting Displays (HMDs), desktop computers, and the like. However, it will be readily apparent to those skilled in the art that the configuration according to the embodiment described in the present specification may be applied to a display capable device even in a new product form to be developed later.

1 is a conceptual diagram illustrating an embodiment of a display device using a semiconductor light emitting device of the present invention, FIG. 2 is a partial enlarged view of part A of the display device of FIG. 1 , and FIG. 3 is an enlarged view of the semiconductor light emitting device of FIG. 2 FIG. 4 is an enlarged view showing another embodiment of the semiconductor light emitting device of FIG. 2 .

As illustrated, information processed by the control unit of the display apparatus 100 may be output from the display module 140 . A closed-loop case 101 surrounding an edge of the display module may form a bezel of the display device.

The display module 140 includes a panel 141 on which an image is displayed, and the panel 141 includes a micro-sized semiconductor light emitting device 150 and a wiring board 110 on which the semiconductor light emitting device 150 is mounted. can be provided.

A wiring may be formed on the wiring board 110 to be connected to the n-type electrode 152 and the p-type electrode 156 of the semiconductor light emitting device 150 . Through this, the semiconductor light emitting device 150 may be provided on the wiring board 110 as an individual pixel that emits light.

The image displayed on the panel 141 is visual information, and is realized by independently controlling light emission of sub-pixels arranged in a matrix form through the wiring.

In the present invention, a micro LED (Light Emitting Diode) is exemplified as a type of the semiconductor light emitting device 150 that converts current into light. The micro LED may be a light emitting diode formed in a small size of 100 micrometers or less. In the semiconductor light emitting device 150 , blue, red, and green colors are provided in the light emitting region, respectively, and a unit pixel may be realized by a combination thereof. That is, the unit pixel means a minimum unit for realizing one color, and at least three micro LEDs may be provided in the unit pixel.

More specifically, referring to FIG. 3 , the semiconductor light emitting device 150 may have a vertical structure.

For example, the semiconductor light emitting device 150 is mainly made of gallium nitride (GaN), and indium (In) and/or aluminum (Al) are added together to be implemented as a high output light emitting device that emits various lights including blue. can be

The vertical semiconductor light emitting device includes a p-type electrode 156 , a p-type semiconductor layer 155 formed on the p-type electrode 156 , an active layer 154 formed on the p-type semiconductor layer 155 , and an active layer 154 . It includes an n-type semiconductor layer 153 formed thereon, and an n-type electrode 152 formed on the n-type semiconductor layer 153 . In this case, the lower p-type electrode 156 may be electrically connected to the p-electrode of the wiring board, and the upper n-type electrode 152 may be electrically connected to the n-electrode at the upper side of the semiconductor light emitting device. The vertical semiconductor light emitting device 150 has a great advantage in that it is possible to reduce the chip size because electrodes can be arranged up and down.

As another example, referring to FIG. 4 , the semiconductor light emitting device may be a flip chip type light emitting device.

For this example, the semiconductor light emitting device 150' is formed on the p-type electrode 156', the p-type semiconductor layer 155' on which the p-type electrode 156' is formed, and the p-type semiconductor layer 155'. The formed active layer 154', the n-type semiconductor layer 153' formed on the active layer 154', and the n-type semiconductor layer 153' are spaced apart from the p-type electrode 156' in the horizontal direction. electrode 152'. In this case, both the p-type electrode 156 ′ and the n-type electrode 152 ′ may be electrically connected to the p-electrode and the n-electrode of the wiring board under the semiconductor light emitting device.

The vertical semiconductor light emitting device and the horizontal semiconductor light emitting device may be a green semiconductor light emitting device, a blue semiconductor light emitting device, or a red semiconductor light emitting device, respectively. In the case of a green semiconductor light emitting device and a blue semiconductor light emitting device, gallium nitride (GaN) is mainly used, and indium (In) and/or aluminum (Al) are added together to implement a high output light emitting device that emits green or blue light. can be For this example, the semiconductor light emitting device may be a gallium nitride thin film formed in various layers such as n-Gan, p-Gan, AlGaN, InGan, and specifically, the p-type semiconductor layer is P-type GaN, and the n The type semiconductor layer may be N-type GaN. However, in the case of a red semiconductor light emitting device, the p-type semiconductor layer may be P-type GaAs, and the n-type semiconductor layer may be N-type GaAs.

Also, the p-type semiconductor layer may be P-type GaN doped with Mg on the p-electrode side, and the n-type semiconductor layer may be N-type GaN doped with Si on the n-electrode side. In this case, the above-described semiconductor light emitting devices may be semiconductor light emitting devices without an active layer.

On the other hand, referring to FIGS. 1 to 4 , since the light emitting diode is very small, unit pixels that emit self-luminescence can be arranged in a high definition in the display panel, thereby realizing a high-definition display device.

In the display device using the semiconductor light emitting device of the present invention described above, the semiconductor light emitting device grown on a wafer and formed through mesa and isolation is used as an individual pixel. In this case, the micro-sized semiconductor light emitting device 150 must be transferred to a predetermined position on the substrate of the display panel on the wafer. There is a pick and place method as such a transfer technology, but the success rate is low and a lot of time is required. As another example, there is a technique of transferring several devices at once using a stamp or a roll, but there is a limit to the yield, so it is not suitable for a large screen display. The present invention proposes a new manufacturing method and manufacturing apparatus of a display device that can solve these problems.

To this end, a new method of manufacturing a display device will be first described below. 5A to 5E are conceptual views for explaining a new process of manufacturing the above-described semiconductor light emitting device.

In the present specification, a display device using a passive matrix (PM) type semiconductor light emitting device is exemplified. However, the examples described below are also applicable to an active matrix (AM) type semiconductor light emitting device. In addition, although a method of self-assembling a horizontal semiconductor light emitting device is exemplified, it is also applicable to a method of self-assembling a vertical semiconductor light emitting device.

First, according to the manufacturing method, the first conductivity type semiconductor layer 153 , the active layer 154 , and the second conductivity type semiconductor layer 155 are grown on the growth substrate 159 , respectively ( FIG. 5A ).

After the first conductivity type semiconductor layer 153 is grown, an active layer 154 is grown on the first conductivity type semiconductor layer 153 , and then a second conductivity type semiconductor is grown on the active layer 154 . Layer 155 is grown. In this way, when the first conductivity type semiconductor layer 153, the active layer 154, and the second conductivity type semiconductor layer 155 are sequentially grown, as shown in FIG. 5A, the first conductivity type semiconductor layer 153 , the active layer 154 and the second conductive semiconductor layer 155 form a stacked structure.

In this case, the first conductivity-type semiconductor layer 153 may be a p-type semiconductor layer, and the second conductivity-type semiconductor layer 155 may be an n-type semiconductor layer. However, the present invention is not necessarily limited thereto, and examples in which the first conductivity type is n-type and the second conductivity type is p-type are also possible.

In addition, although the case in which the active layer is present is exemplified in this embodiment, a structure without the active layer is possible in some cases as described above. As an example, the p-type semiconductor layer may be P-type GaN doped with Mg, and the n-type semiconductor layer may be N-type GaN doped with Si on the n-electrode side.

The growth substrate 159 (wafer) may be formed of a material having a light-transmitting property, for example, any one of sapphire (Al2O3), GaN, ZnO, and AlO, but is not limited thereto. In addition, the growth substrate 1059 may be formed of a material suitable for semiconductor material growth, a carrier wafer. It may be formed of a material having excellent thermal conductivity, and, including a conductive substrate or an insulating substrate, for example, a SiC substrate having higher thermal conductivity than a sapphire (Al2O3) substrate or at least one of Si, GaAs, GaP, InP, Ga2O3 can be used

Next, at least some of the first conductivity type semiconductor layer 153 , the active layer 154 , and the second conductivity type semiconductor layer 155 are removed to form a plurality of semiconductor light emitting devices ( FIG. 5B ).

More specifically, isolation is performed so that the plurality of light emitting devices form a light emitting device array. That is, the first conductivity type semiconductor layer 153 , the active layer 154 , and the second conductivity type semiconductor layer 155 are vertically etched to form a plurality of semiconductor light emitting devices.

In the case of forming a horizontal type semiconductor light emitting device, the active layer 154 and the second conductivity type semiconductor layer 155 are partially removed in the vertical direction so that the first conductivity type semiconductor layer 153 is exposed to the outside. An exposed mesa process, followed by an isolation of the first conductive semiconductor layer to form a plurality of semiconductor light emitting device arrays by etching may be performed.

Next, second conductivity type electrodes 156 (or p-type electrodes) are respectively formed on one surface of the second conductivity type semiconductor layer 155 ( FIG. 5C ). The second conductive electrode 156 may be formed by a deposition method such as sputtering, but the present invention is not limited thereto. However, when the first conductive semiconductor layer and the second conductive semiconductor layer are an n-type semiconductor layer and a p-type semiconductor layer, respectively, the second conductive electrode 156 may be an n-type electrode.

Then, the growth substrate 159 is removed to provide a plurality of semiconductor light emitting devices. For example, the growth substrate 1059 may be removed using a laser lift-off (LLO) method or a chemical lift-off (CLO) method ( FIG. 5D ).

Thereafter, a step of mounting the semiconductor light emitting devices 150 on a substrate in a chamber filled with a fluid is performed ( FIG. 5E ).

For example, the semiconductor light emitting devices 150 and the substrate are put in a chamber filled with a fluid, and the semiconductor light emitting devices are self-assembled on the substrate 161 using flow, gravity, surface tension, and the like. In this case, the substrate may be the assembly substrate 161 .

As another example, it is also possible to put a wiring board in the assembly chamber instead of the assembly board 161 so that the semiconductor light emitting devices 150 are directly seated on the wiring board. In this case, the substrate may be a wiring substrate. However, for convenience of explanation, in the present invention, the substrate is provided as the assembly substrate 161 to exemplify that the semiconductor light emitting devices 1050 are seated.

Cells (not shown) in which the semiconductor light emitting devices 150 are inserted may be provided on the assembly substrate 161 to facilitate mounting of the semiconductor light emitting devices 150 on the assembly substrate 161 . Specifically, cells in which the semiconductor light emitting devices 150 are seated are formed on the assembly substrate 161 at positions where the semiconductor light emitting devices 150 are aligned with the wiring electrodes. The semiconductor light emitting devices 150 are assembled to the cells while moving in the fluid.

After a plurality of semiconductor light emitting devices are arrayed on the assembly board 161 , when the semiconductor light emitting devices of the assembly board 161 are transferred to a wiring board, large-area transfer is possible. Accordingly, the assembly substrate 161 may be referred to as a temporary substrate.

On the other hand, in order to apply the self-assembly method described above to the manufacture of a large-screen display, it is necessary to increase the transfer yield. The present invention proposes a method and apparatus for minimizing the influence of gravity or frictional force and preventing non-specific binding in order to increase the transfer yield.

In this case, in the display device according to the present invention, a magnetic material is disposed on the semiconductor light emitting device to move the semiconductor light emitting device using magnetic force, and the semiconductor light emitting device is seated at a predetermined position by using an electric field during the movement process. Hereinafter, such a transfer method and apparatus will be described in more detail with the accompanying drawings.

6 is a conceptual diagram illustrating an example of a self-assembly apparatus for a semiconductor light emitting device according to the present invention, and FIG. 7 is a block diagram of the self-assembly apparatus of FIG. 6 . 8A to 8D are conceptual views illustrating a process of self-assembling a semiconductor light emitting device using the self-assembly apparatus of FIG. 6 , and FIG. 9 is a conceptual diagram for explaining the semiconductor light emitting device of FIGS. 8A to 8D .

6 and 7 , the self-assembly apparatus 160 of the present invention may include an assembly chamber 162 , a magnet 163 and a position control unit 164 .

The assembly chamber 162 has a space for accommodating a plurality of semiconductor light emitting devices. The space may be filled with a fluid, and the fluid may include water as an assembly solution. Accordingly, the assembly chamber 162 may be a water tank and may be configured as an open type. However, the present invention is not limited thereto, and the assembly chamber 162 may be of a closed type in which the space is a closed space.

A substrate 161 may be disposed in the assembly chamber 162 so that an assembly surface on which the semiconductor light emitting devices 150 are assembled faces downward. For example, the substrate 161 may be transferred to an assembly position by a transfer unit, and the transfer unit may include a stage 165 on which the substrate is mounted. The position of the stage 165 is adjusted by the controller, and through this, the substrate 161 can be transferred to the assembly position.

At this time, in the assembly position, the assembly surface of the substrate 161 faces the bottom of the assembly chamber 150 . As shown, the assembly surface of the substrate 161 is disposed to be immersed in the fluid in the assembly chamber 162 . Accordingly, the semiconductor light emitting device 150 moves to the assembly surface in the fluid.

The substrate 161 is an assembled substrate capable of forming an electric field, and may include a base portion 161a, a dielectric layer 161b, and a plurality of electrodes 161c.

The base portion 161a may be made of an insulating material, and the plurality of electrodes 161c may be a thin film or a thick film bi-planar electrode patterned on one surface of the base portion 161a. The electrode 161c may be formed of, for example, a stack of Ti/Cu/Ti, Ag paste, ITO, or the like.

The dielectric layer 161b is made of an inorganic material such as SiO2, SiNx, SiON, Al2O3, TiO2, HfO2, or the like. Alternatively, the dielectric layer 161b may be configured as a single layer or multi-layer as an organic insulator. The dielectric layer 161b may have a thickness of several tens of nm to several μm.

Furthermore, the substrate 161 according to the present invention includes a plurality of cells 161d partitioned by barrier ribs. The cells 161d are sequentially arranged in one direction and may be made of a polymer material. Also, the partition walls 161e forming the cells 161d are shared with the neighboring cells 161d. The partition wall 161e protrudes from the base portion 161a, and the cells 161d may be sequentially disposed along one direction by the partition wall 161e. More specifically, the cells 161d are sequentially arranged in the column and row directions, respectively, and may have a matrix structure.

Inside the cells 161d, as shown, a groove for accommodating the semiconductor light emitting device 150 is provided, and the groove may be a space defined by the partition wall 161e. The shape of the groove may be the same as or similar to that of the semiconductor light emitting device. For example, when the semiconductor light emitting device has a rectangular shape, the groove may have a rectangular shape. Also, although not shown, when the semiconductor light emitting device has a circular shape, the grooves formed in the cells may have a circular shape. Furthermore, each of the cells is configured to accommodate a single semiconductor light emitting device. That is, one semiconductor light emitting device is accommodated in one cell.

Meanwhile, the plurality of electrodes 161c may include a plurality of electrode lines disposed at the bottom of each of the cells 161d, and the plurality of electrode lines may extend to adjacent cells.

The plurality of electrodes 161c are disposed below the cells 161d, and different polarities are applied to each other to generate an electric field in the cells 161d. To form the electric field, the dielectric layer may form the bottom of the cells 161d while covering the plurality of electrodes 161c with the dielectric layer. In this structure, when different polarities are applied to the pair of electrodes 161c under each of the cells 161d, an electric field is formed, and the semiconductor light emitting device can be inserted into the cells 161d by the electric field. there is.

In the assembly position, the electrodes of the substrate 161 are electrically connected to the power supply unit 171 . The power supply unit 171 applies power to the plurality of electrodes to generate the electric field.

As illustrated, the self-assembly apparatus may include a magnet 163 for applying a magnetic force to the semiconductor light emitting devices. The magnet 163 is spaced apart from the assembly chamber 162 to apply a magnetic force to the semiconductor light emitting devices 150 . The magnet 163 may be disposed to face the opposite surface of the assembly surface of the substrate 161 , and the position of the magnet is controlled by the position controller 164 connected to the magnet 163 .

The semiconductor light emitting device 1050 may include a magnetic material to move in the fluid by the magnetic field of the magnet 163 .

Referring to FIG. 9 , in a semiconductor light emitting device including a magnetic material, a first conductivity type electrode 1052 , a second conductivity type electrode 1056 , and a first conductivity type semiconductor layer in which the first conductivity type electrode 1052 are disposed (1053), a second conductivity type semiconductor layer 1055 overlapping the first conductivity type semiconductor layer 1052 and on which the second conductivity type electrode 1056 is disposed, and the first and second conductivity type semiconductors an active layer 1054 disposed between the layers 1053 and 1055 .

Here, the first conductivity type may be p-type, the second conductivity type may be n-type, and vice versa. In addition, as described above, the semiconductor light emitting device without the active layer may be used.

Meanwhile, in the present invention, the first conductive electrode 1052 may be generated after the semiconductor light emitting device is assembled on the wiring board by self-assembly of the semiconductor light emitting device. Also, in the present invention, the second conductive electrode 1056 may include the magnetic material. The magnetic material may mean a magnetic metal. The magnetic material may be Ni, SmCo, or the like, and as another example, may include a material corresponding to at least one of Gd-based, La-based, and Mn-based materials.

The magnetic material may be provided on the second conductive electrode 1056 in the form of particles. Alternatively, in a conductive electrode including a magnetic material, one layer of the conductive electrode may be formed of a magnetic material. For this example, as shown in FIG. 9 , the second conductive electrode 1056 of the semiconductor light emitting device 1050 may include a first layer 1056a and a second layer 1056b. Here, the first layer 1056a may include a magnetic material, and the second layer 1056b may include a metal material rather than a magnetic material.

As shown, in this example, the first layer 1056a including a magnetic material may be disposed to contact the second conductive semiconductor layer 1055 . In this case, the first layer 1056a is disposed between the second layer 1056b and the second conductivity type semiconductor layer 1055 . The second layer 1056b may be a contact metal connected to the second electrode of the wiring board. However, the present invention is not necessarily limited thereto, and the magnetic material may be disposed on one surface of the first conductivity type semiconductor layer.

Referring back to FIGS. 6 and 7 , more specifically, the self-assembly device includes a magnet handler that can be moved automatically or manually in the x, y, and z axes on the upper portion of the assembly chamber, or the magnet 163 . It may be provided with a motor capable of rotating the. The magnet handler and the motor may constitute the position control unit 164 . Through this, the magnet 163 rotates in a horizontal direction, clockwise or counterclockwise direction with the substrate 161 .

Meanwhile, a light-transmitting bottom plate 166 may be formed in the assembly chamber 162 , and the semiconductor light emitting devices may be disposed between the bottom plate 166 and the substrate 161 . An image sensor 167 may be disposed to face the bottom plate 166 to monitor the inside of the assembly chamber 162 through the bottom plate 166 . The image sensor 167 is controlled by the controller 172 and may include an inverted type lens and a CCD to observe the assembly surface of the substrate 161 .

The self-assembly apparatus described above is made to use a combination of a magnetic field and an electric field, and using this, the semiconductor light emitting devices are seated at a predetermined position on the substrate by an electric field in the process of moving by a change in the position of the magnet. can Hereinafter, the assembly process using the self-assembly apparatus described above will be described in more detail.

First, a plurality of semiconductor light emitting devices 1050 including a magnetic material are formed through the process described with reference to FIGS. 5A to 5C . In this case, in the process of forming the second conductive type electrode of FIG. 5C , a magnetic material may be deposited on the semiconductor light emitting device.

Next, the substrate 161 is transferred to the assembly position, and the semiconductor light emitting devices 1050 are put into the assembly chamber 162 ( FIG. 8A ).

As described above, the assembly position of the substrate 161 will be a position in which the assembly chamber 162 is disposed so that the assembly surface of the substrate 161 on which the semiconductor light emitting devices 1050 are assembled faces downward. can

In this case, some of the semiconductor light emitting devices 1050 may sink to the bottom of the assembly chamber 162 and some may float in the fluid. When the light-transmitting bottom plate 166 is provided in the assembly chamber 162 , some of the semiconductor light emitting devices 1050 may sink to the bottom plate 166 .

Next, a magnetic force is applied to the semiconductor light emitting devices 1050 so that the semiconductor light emitting devices 1050 vertically float in the assembly chamber 162 ( FIG. 8B ).

When the magnet 163 of the self-assembly device moves from its original position to the opposite surface of the assembly surface of the substrate 161 , the semiconductor light emitting devices 1050 float toward the substrate 161 in the fluid. The original position may be a position deviated from the assembly chamber 162 . As another example, the magnet 163 may be configured as an electromagnet. In this case, electricity is supplied to the electromagnet to generate an initial magnetic force.

Meanwhile, in this example, when the magnitude of the magnetic force is adjusted, the separation distance between the assembly surface of the substrate 161 and the semiconductor light emitting devices 1050 may be controlled. For example, the separation distance is controlled using the weight, buoyancy, and magnetic force of the semiconductor light emitting devices 1050 . The separation distance may be several millimeters to several tens of micrometers from the outermost surface of the substrate.

Next, a magnetic force is applied to the semiconductor light emitting devices 1050 so that the semiconductor light emitting devices 1050 move in one direction in the assembly chamber 162 . For example, the magnet 163 moves in a direction horizontal to the substrate, clockwise or counterclockwise ( FIG. 8C ). In this case, the semiconductor light emitting devices 1050 move in a direction parallel to the substrate 161 at a position spaced apart from the substrate 161 by the magnetic force.

Next, in the process of moving the semiconductor light emitting devices 1050, applying an electric field to guide the semiconductor light emitting devices 1050 to the preset position so that they are seated at a preset position of the substrate 161 is proceed (Fig. 8c). For example, while the semiconductor light emitting devices 1050 are moving in a direction horizontal to the substrate 161, they are moved in a direction perpendicular to the substrate 161 by the electric field, thereby causing the installed in the set position.

More specifically, an electric field is generated by supplying power to the bi-planar electrode of the substrate 161 , and assembly is induced only at a preset position using this. That is, by using the selectively generated electric field, the semiconductor light emitting devices 1050 are self-assembled at the assembly position of the substrate 161 . To this end, cells in which the semiconductor light emitting devices 1050 are inserted may be provided on the substrate 161 .

Thereafter, the unloading process of the substrate 161 is performed, and the assembly process is completed. When the substrate 161 is an assembly substrate, a post-process for realizing a display device by transferring the semiconductor light emitting devices arranged as described above to a wiring substrate may be performed.

On the other hand, after guiding the semiconductor light emitting devices 1050 to the predetermined position, the magnet so that the semiconductor light emitting devices 1050 remaining in the assembly chamber 162 fall to the bottom of the assembly chamber 162 . The 163 may be moved in a direction away from the substrate 161 ( FIG. 8D ). As another example, when power supply is stopped when the magnet 163 is an electromagnet, the semiconductor light emitting devices 1050 remaining in the assembly chamber 162 fall to the floor of the assembly chamber 162 .

Thereafter, when the semiconductor light emitting devices 1050 at the bottom of the assembly chamber 162 are recovered, the recovered semiconductor light emitting devices 1050 can be reused.

The self-assembly apparatus and method described above uses a magnetic field to concentrate distant parts near a predetermined assembly site to increase the assembly yield in fluidic assembly, and applies a separate electric field to the assembly site so that the parts are selectively transferred only to the assembly site. to be assembled. At this time, the assembly board is placed on the upper part of the water tank and the assembly surface is directed downward to minimize the effect of gravity due to the weight of the parts and prevent non-specific binding to eliminate defects. That is, to increase the transfer yield, the assembly substrate is placed on the upper part to minimize the effect of gravity or frictional force, and to prevent non-specific binding.

As described above, according to the present invention having the above configuration, in a display device in which individual pixels are formed of semiconductor light emitting devices, a large number of semiconductor light emitting devices can be assembled at once.

As described above, according to the present invention, it is possible to pixelate a semiconductor light emitting device in a large amount on a small-sized wafer and then transfer it to a large-area substrate. Through this, it is possible to manufacture a large-area display device at a low cost.

When performing the self-assembly process described above, several problems arise.

First, as the area of the display increases, the area of the assembly substrate increases. As the area of the assembly substrate increases, the bending phenomenon of the substrate increases. When self-assembly is performed in a curved state of the assembly substrate, since a magnetic field is not uniformly formed on the surface of the assembly substrate, it is difficult to stably perform self-assembly.

Second, since the semiconductor light emitting device cannot be completely uniformly dispersed in the fluid, and the magnetic field formed on the surface of the assembly substrate cannot be perfectly uniform, a problem that the semiconductor light emitting device is concentrated only on a part of the assembly substrate may occur. can

The present invention provides a self-assembly apparatus capable of increasing the self-assembly yield as well as the above-described problems.

The self-assembly apparatus according to the present invention may include a substrate surface treatment unit, a substrate chuck 200 , a magnetic field forming unit 300 , a chip supply unit 400 , and an assembly chamber 500 . However, the present invention is not limited thereto, and the self-assembly apparatus according to the present invention may include more or fewer components than the above-described components.

Before describing the self-assembly apparatus according to the present invention, a self-assembly method using the self-assembly apparatus according to the present invention will be briefly described.

10 is a flowchart illustrating a self-assembly method according to the present invention.

First, the surface treatment step (S110) of the assembly substrate is performed. Although this step is not essential, when the surface of the substrate becomes hydrophilic, it is possible to prevent bubbles from forming on the surface of the substrate.

Next, a step ( S120 ) of loading the assembly substrate into the substrate chuck is performed. The assembly substrate loaded on the substrate chuck 200 is transferred to an assembly position of the assembly chamber. Thereafter, the magnetic field forming unit approaches the assembly substrate through vertical and horizontal movement.

In this state, the step of supplying the chip (S130) proceeds. Specifically, the step of dispersing the semiconductor light emitting device on the assembly surface of the assembly substrate proceeds. When the semiconductor light emitting device is dispersed near the assembly surface while the magnetic field forming unit 300 is sufficiently close to the assembly substrate, the semiconductor light emitting device is attached to the assembly surface by the magnetic field forming unit. The semiconductor light emitting devices are dispersed on the assembly surface with a suitable dispersion.

However, the present invention is not limited thereto, and the semiconductor light emitting device may be dispersed in the fluid in the assembly chamber before the substrate is transferred to the assembly position. That is, the timing of performing the chip supply step ( S130 ) is not limited to after the assembly substrate is transferred to the assembly position.

The supply method of the semiconductor light emitting device may vary depending on the area of the assembly substrate, the type of the semiconductor light emitting device to be assembled, the self-assembly speed, and the like.

After that, self-assembly is performed and a step (S140) of recovering the semiconductor light emitting device is performed. The self-assembly will be described later along with a description of the self-assembly apparatus according to the present invention. On the other hand, the semiconductor light emitting device does not necessarily need to be recovered after self-assembly. After the self-assembly is completed, self-assembly of a new substrate may be performed after replenishing the semiconductor light emitting device in the assembly chamber.

Finally, after the self-assembly is completed, a step (S150) of inspecting and drying the assembly substrate and separating the substrate from the substrate chuck may be performed. The inspection of the assembly board may be performed at a position where self-assembly is performed, and may be performed after transferring the assembly board to another location.

Meanwhile, drying of the assembly substrate may be performed after the assembly substrate is separated from the fluid. After drying the assembly substrate, a self-assembly post process may be performed.

The basic principle of self-assembly, the structure of the substrate (or assembly substrate), and the contents of the semiconductor light emitting device are replaced with those described in FIGS. 1 to 9 . On the other hand, the vertical moving part, the horizontal moving part, the rotating part and other moving means described below can be implemented through known various means, such as a motor and a ball screw, a rack gear and a pinion gear, a pulley and a timing belt, so the detailed description is omit

On the other hand, the control unit 172 described with reference to FIG. 7 controls the movements of the vertical moving unit, the horizontal moving unit, the rotating unit, and other moving means provided in the above-described components. That is, the control unit 172 is configured to control the movement and rotation movement of the x, y, and z axes of each component. Although not mentioned otherwise in this specification, the movement of the vertical moving unit, the horizontal moving unit, the rotating unit and other moving means is generated by the control of the controller 172 .

On the other hand, the electrode 161c provided in the substrate (or assembly substrate, 161) described in FIGS. 6 to 9 is referred to as an assembly electrode, and the assembly electrode 161c is the power supply unit described in FIG. 7 through the substrate chuck 200 ( 171), and the power supply unit 171 supplies power to the assembly electrode 161c under the control of the control unit 172. A detailed description thereof will be given later.

Hereinafter, the above-described components will be described.

First, the substrate surface treatment unit serves to make the substrate surface hydrophilic. Specifically, the self-assembly apparatus according to the present invention performs self-assembly in a state in which the assembly substrate is in contact with the fluid surface. When the assembly surface of the assembly substrate has a property different from the fluid surface, bubbles may occur on the assembly surface, and non-specific bonding between the semiconductor light emitting device and the assembly surface may occur. To prevent this, the substrate surface before self-assembly can be treated with a fluid-friendly property.

In an embodiment, when the fluid is a polar material such as water, the substrate surface treatment unit may make the assembly surface of the substrate hydrophilic.

For example, the substrate surface treatment unit may include a plasma generator. Through plasma treatment of the substrate surface, hydrophilic functional groups may be formed on the substrate surface. Specifically, hydrophilic functional groups may be formed on at least one of a barrier rib and a dielectric layer provided in the substrate through plasma processing.

Meanwhile, different surface treatments may be applied to the surface of the barrier rib and the surface of the dielectric layer exposed to the outside by the cell to prevent non-specific binding of the semiconductor light emitting device. For example, a hydrophilic treatment may be performed on the surface of the dielectric layer exposed to the outside by the cell, and the surface treatment may be performed to form a hydrophobic functional group on the surface of the barrier rib. Through this, non-specific binding of the semiconductor light emitting device to the barrier rib surface may be prevented, and the semiconductor light emitting device may be strongly fixed inside the cell.

However, the substrate surface treatment unit is not an essential component in the self-assembly apparatus according to the present invention. The substrate surface treatment unit may not be necessary depending on the constituent materials constituting the substrate.

The substrate on which the surface treatment has been completed by the substrate surface treatment unit is loaded into the substrate chuck 200 .

Next, the substrate chuck 200 will be described.

11 is a conceptual diagram illustrating a first state of the substrate chuck, FIG. 12 is a conceptual diagram illustrating a second state of the substrate chuck, FIG. 13 is a plan view of a first frame provided in the substrate chuck, and FIG. It is a conceptual diagram showing the loaded state.

Referring to the accompanying drawings, the substrate chuck 200 includes a substrate support. In an embodiment, the substrate support unit includes first and second frames 210 and 220 , and a fixing unit 230 . The first and second frames 210 and 220 are vertically disposed with a loaded substrate therebetween, and the fixing unit 230 supports the first and second frames 210 and 220 . The substrate chuck 200 may include a rotating unit 240 , a vertical moving unit, and a horizontal moving unit 250 . 11 , the vertical moving unit and the horizontal moving unit 250 may be configured as one device. Meanwhile, without being limited to the drawings to be described later, the rotating unit and the vertical and horizontal moving units provided in the substrate chuck may be formed as a single device.

In this specification, the first frame 210 is defined as a frame disposed below the substrate in a state where the assembly surface of the substrate S faces the fluid, and the second frame 220 is defined as a frame in which the assembly surface of the substrate S faces the fluid. It is defined as a frame disposed on the upper side of the substrate. Due to the rotation unit 240 , the vertical relationship between the first frame 210 and the second frame 220 may be switched with each other. In the present specification, a state in which the first frame 210 is lower than the second frame 220 is defined as a first state (see FIG. 11 ), and the first frame 210 is the second frame 220 . A state above it is defined as a second state (refer to FIG. 12). The rotating unit 240 rotates at least one of the first and second frames 210 and 220 and the fixing unit 230 to switch from any one of the first and second states to the other. The rotating part 240 will be described later.

The first frame 210 is a frame that comes into contact with the fluid filled in the assembly chamber during self-assembly. Referring to FIG. 14 , the first frame 210 includes a bottom portion 210 ′ and a side wall portion 210 ″.

The bottom portion 210 ′ serves to support the substrate at the lower or upper side of the substrate S when the substrate S is loaded. The bottom portion 210 ′ may be formed in a single plate shape or in a form in which a plurality of members forming a plate shape are combined. Referring to FIG. 13 , the bottom portion 210 ′ has a hole 210 ″″ passing through the central portion. The hole 210''' exposes a substrate, which will be described later, to the outside so that it can be in contact with the fluid. That is, the hole 210 ″″ defines an assembly surface of the substrate. The substrate is loaded so that the four corners of the rectangular substrate span the rim of the hole 210 ″″ of the first frame 210 . Accordingly, the remaining area except for the edge of the substrate overlaps the hole 210 ″″ provided in the first frame 210 . The area of the substrate overlapping the hole 210 ″″ becomes the assembly surface.

Meanwhile, a sealing part 212 and an electrode connection part 213 may be disposed on the edge of the hole 210 ″″.

The sealing part 212 is in close contact with the substrate to prevent the fluid filled in the assembly chamber from penetrating into the first and second frames 210 and 220 during self-assembly. In addition, the sealing part 212 prevents the fluid from penetrating into the assembly electrode 161c and the electrode connection part 213 . To this end, the sealing part 212 should be disposed at a position closer to the hole 210 ″″ than the electrode connection part 213 .

The sealing part 212 is formed in a ring shape, and the material of the sealing part 212 is not specifically limited. The material constituting the sealing portion 212 may be a known sealing material.

The electrode connection part 213 is connected to the assembly electrode formed on the substrate to supply power to the assembly electrode. In an embodiment, the electrode connection unit 213 applies power supplied from the power supply unit 171 illustrated in FIG. 7 to the assembly electrode 161c to form an electric field on the substrate.

Meanwhile, the side wall portion 210 ″ is formed on the edge of the bottom portion 210 ′. The side wall portion 210'' prevents fluid from penetrating into the opposite surface of the assembly surface of the substrate during self-assembly. Specifically, the self-assembly apparatus according to the present invention performs self-assembly in a state in which the substrate is immersed in the fluid. The side wall portion 210 ″ prevents the fluid from penetrating into the opposite surface of the assembly surface of the substrate when the substrate is immersed in the fluid.

To this end, the side wall portion 210 ″ is formed to surround the entire edge of the substrate. The height of the side wall portion 210 ″ should be greater than the depth at which the substrate is immersed in the fluid. The side wall portion 210 ″ prevents the fluid from penetrating the opposite surface of the assembly surface of the substrate, thereby preventing the substrate from being damaged, and allowing the buoyancy force of the fluid to act only on one surface of the substrate. This will be described later.

Meanwhile, the second frame 220 serves to press the substrate from the opposite side of the first frame 210 during self-assembly. Like the first frame 210 , the second frame 220 has a hole penetrating through the center portion. The hole formed in the second frame 220 is formed to be larger than or equal to the hole 210 ″″ formed in the first frame 210 .

The hole formed in the second frame 220 allows the opposite surface of the assembly surface of the substrate to be exposed to the outside. The opposite surface of the assembly surface of the substrate should be exposed to the outside with the same area as the assembly surface or a larger area than the assembly surface. This is because the magnetic field forming unit 300 forms a magnetic field on the opposite side of the assembly surface of the substrate. The opposite surface of the assembly surface of the substrate should be exposed to the outside so that the magnetic field forming unit 300 can be sufficiently close to the substrate.

Meanwhile, the substrate S is loaded between the first and second frames 210 and 220 in the second state. Accordingly, the substrate S is loaded while sliding on one surface of the second frame 220 . A protrusion for guiding an alignment position of the substrate may be formed on at least one of the first and second frames so that the substrate is aligned at a correct position. In an embodiment, referring to FIG. 13 , a protrusion 211 for guiding an alignment position of the substrate S may be formed in the first frame 210 .

On the other hand, when the substrate S is loaded on the second frame 220, at least one of the first and second frames 210 and 220 performs vertical movement so that the first and second frames 210 and 220) to pressurize the substrate. To this end, the substrate chuck 200 may include a frame moving unit disposed on at least one of the fixing unit 230 , the first frame, and the second frame 210 and 220 . At this time, the sealing part 212 presses the substrate (S).

In an embodiment, a frame moving unit for vertically moving the second frame 220 may be disposed on the fixing unit 230 . In the second state of the substrate chuck, when the substrate S is loaded on the second frame 220 , the vertical movement unit moves the second frame 220 upward, so that the substrate S is moved to the second frame 220 . To be strongly fixed between the first and second frames (210 and 220). At this time, the electrode connection part 213 provided in the first frame 210 is connected to the assembly electrode of the substrate S, and the sealing part 212 provided in the first frame 210 is the edge of the substrate S. will pressurize When the substrate chuck is switched to the first state in this state, a shape as shown in FIG. 14 is obtained.

However, the present invention is not limited thereto, and the frame moving unit may be formed to horizontally move any one of the first and second frames 210 and 220 with respect to the other. In this case, the frame moving unit is configured to vertically and horizontally move any one of the first and second frames 210 and 220 with respect to the other. When any one of the first and second frames 210 and 220 can be moved horizontally with respect to the other, the connection portion between the electrode connection part 213 and the assembled electrode can be changed. This can be utilized to detect whether the assembled electrode is defective.

Meanwhile, the rotating part 240 is disposed on one side of the fixing part 230 provided in the above-described substrate chuck 200 . The rotating unit 240 rotates the fixing unit 230 so that the vertical relationship between the first and second frames 210 and 220 can be switched. The substrate chuck 200 is switched from any one of the first and second states to the other by the rotational movement of the rotating part 240 . The rotation speed, rotation degree, rotation direction, and the like of the rotation unit 240 may be controlled by the control unit 172 described with reference to FIG. 7 .

In an embodiment, the substrate chuck 200 is in the second state before loading the substrate S, and the control unit 172 controls the rotation unit 240 to rotate the fixing unit 230 by 180 degrees after the substrate S is loaded. Rotate so that the substrate chuck 200 is switched to the first state.

Meanwhile, a vertical moving part and a horizontal moving part are disposed on one side of the fixing part 230 .

The horizontal moving unit moves at least one of the fixing unit 230 and the first and second frames 210 and 220 so that the assembly surface of the substrate may be aligned in the open position of the assembly chamber after loading the substrate.

The vertical moving unit moves at least one of the fixing unit 230 and the first and second frames 210 and 220 so that a vertical distance between the substrate and the assembly chamber is adjusted. The warpage of the substrate S may be corrected through the vertical movement unit. This will be described later.

In summary, the substrate S is loaded in the substrate chuck 200 in the second state (refer to FIG. 12 ). Thereafter, after the substrate chuck 200 is switched to the first state (refer to FIG. 11 ), it is aligned with the assembly chamber. In this process, the substrate chuck 200 moves vertically and horizontally so that the assembly surface of the substrate S comes into contact with the fluid filled in the assembly chamber. Thereafter, the control unit 172 controls the magnetic field forming unit 300 .

Next, the magnetic field forming unit 300 will be described.

15 is a perspective view of a magnetic field forming unit according to an embodiment of the present invention, FIG. 16 is a side view of a magnetic field forming unit according to an embodiment of the present invention, and FIG. 17 is another magnetic field forming unit according to an embodiment of the present invention. It is a lower side view, and FIG. 18 is a conceptual view showing the trajectories of magnets provided in the magnetic field forming unit according to the present invention.

Referring to the drawings, the magnetic field forming unit 300 includes a magnet array 310 , a vertical moving unit, a horizontal moving unit, and a rotating unit 320 . The magnetic field forming unit 300 is disposed above the assembled electrode to form a magnetic field.

Specifically, the magnet array 310 includes a plurality of magnets 313 . The magnet 313 provided in the magnet array 310 may be a permanent magnet or an electromagnet. The magnets 313 form a magnetic field to guide the semiconductor light emitting devices to the assembly surface of the substrate.

The magnet array 310 may include a support part 311 and a magnet moving part 312 . The support part 311 is connected to the vertical and horizontal movement part 320 .

On the other hand, one end of the magnet moving part 312 is fixed to the support part 311 , and the magnet 313 is fixed to the other end of the magnet moving part 312 . The magnet moving part 312 is made to be stretchable in length. As the magnet moving part 312 expands and contracts, the distance between the magnet 313 and the support part 311 changes.

As shown in the accompanying drawings, the magnet moving unit 312 may be configured to vertically move the magnets 313 arranged in one row at a time. In this case, the magnet moving parts 312 may be arranged for each column of the magnet array.

Alternatively, the magnet moving unit 312 may be disposed as many as the number of magnets provided in the magnet array. Accordingly, a distance between each of the plurality of magnets and the support portion may be adjusted differently.

The plurality of magnet moving parts serves to finely adjust the distance between the magnet 313 and the substrate S, and when the substrate is bent, it serves to uniformly adjust the distance between the magnets 313 and the substrate S . The self-assembly may be performed in a state in which the magnet 313 is in contact with the substrate S, or may be performed in a state in which the magnet 313 is spaced apart from the substrate S by a predetermined distance.

Meanwhile, the horizontal moving unit may include a rotating unit. When self-assembly is performed, the horizontal moving unit provided in the magnetic field forming unit 300 rotates the magnet while moving it in one direction. Accordingly, the magnet array 310 rotates about a predetermined rotation axis and moves along one direction at the same time. For example, referring to FIG. 18 , the magnet 313 provided in the magnet array 310 may move while drawing a trajectory P in which a curved line and a straight line are mixed.

A semiconductor light emitting device may be supplied in a state in which the magnetic field forming unit 300 is close to the substrate S within a predetermined distance.

19 is a conceptual diagram illustrating a state of supplying a semiconductor light emitting device.

Referring to FIG. 19 , a chip supply unit 400 may be disposed in an assembly chamber 500 to be described later. The chip supply unit 400 aligns the substrate S in the assembly chamber 500 and serves to supply the semiconductor light emitting device on the assembly surface of the substrate S. Specifically, the chip supply unit 400 may include a chip receiving unit capable of accommodating a chip, a vertical moving unit, and a horizontal moving unit thereon. The vertical and horizontal moving parts allow the chip accommodating part to move in the fluid filled in the assembly chamber.

A plurality of semiconductor light emitting devices may be loaded in the chip accommodating part. After the substrate is aligned with the assembly chamber, when the magnetic field forming unit 300 is brought closer to the substrate by a predetermined distance or more, a magnetic field of a predetermined strength or more is formed on the assembly surface. When the chip accommodating part approaches the assembly surface within a predetermined distance in this state, the semiconductor light emitting devices loaded in the chip accommodating part come into contact with the substrate. The vertical moving unit provided in the chip supply unit moves the chip receiving unit close to a partial region of the assembly surface of the substrate within a predetermined distance through vertical movement.

After a predetermined time has elapsed, the vertical moving unit provided in the chip supply unit moves the chip receiving unit away from the partial region of the assembly surface of the substrate by a predetermined distance or more through vertical movement. Thereafter, the horizontal moving unit provided in the chip supply unit horizontally moves the chip receiving unit so that the chip receiving unit overlaps a partial region and another region of the assembly surface. Thereafter, the vertical moving unit provided in the chip supply unit moves the chip receiving unit close to the other area within a predetermined distance through vertical movement. By repeating this process, the chip supply unit brings the plurality of semiconductor light emitting devices into contact with the entire area of the assembly surface of the substrate. The self-assembly may be performed in a state in which a plurality of semiconductor light emitting devices are uniformly dispersed and in contact with the entire area of the assembly surface of the substrate.

As described above, there are two major problems in self-assembly. As a second problem, since the semiconductor light emitting device cannot be completely uniformly dispersed in the fluid and the magnetic field formed on the surface of the assembly substrate cannot be perfectly uniform, the semiconductor light emitting device is concentrated only on a part of the assembly substrate. there is If the above-described chip supply unit 400 is used, the second problem described above can be solved.

However, the present invention is not limited thereto, and the chip supply unit is not an essential component of the present invention. The self-assembly may be performed in a state in which the semiconductor light emitting device is dispersed in a fluid, or in a state in which a plurality of semiconductor light emitting devices are dispersed and brought into contact with the assembly surface of the substrate by a part other than the chip supply unit.

Next, the assembly chamber 500 will be described.

20 is a plan view of an assembly chamber according to an embodiment of the present invention, FIG. 21 is a cross-sectional view taken along line A-A' of FIG. 20, and FIGS. 22 and 23 are views of the assembly chamber according to an embodiment of the present invention. It is a conceptual diagram showing the movement of the provided gate.

The assembly chamber 500 has a space for accommodating a plurality of semiconductor light emitting devices. The space may be filled with a fluid, and the fluid may include water as an assembly solution. Accordingly, the assembly chamber 500 may be a water tank, and may be configured as an open type. However, the present invention is not limited thereto, and the assembly chamber 500 may be of a closed type in which the space is a closed space.

The substrate S is disposed in the assembly chamber 500 so that the assembly surface on which the semiconductor light emitting devices 150 are assembled faces downward. For example, the substrate S is transferred to the assembly position by the substrate chuck 200 .

At this time, the assembly surface of the substrate S faces the bottom of the assembly chamber 500 in the assembly position. Accordingly, the assembly surface is oriented in the direction of gravity. The assembly surface of the substrate S is disposed to be immersed in the fluid in the assembly chamber 500 .

In one embodiment, the assembly chamber 500 may be divided into two regions. Specifically, the assembly chamber 500 may be divided into an assembly area 510 and an inspection area 520 . In the assembly region 510 , the semiconductor light emitting device disposed in the fluid is assembled into the substrate S while the substrate S is immersed in the fluid.

Meanwhile, in the inspection area 520 , the self-assembly of the self-assembled substrate S is performed. Specifically, after the substrate S is assembled in the assembly region, it is transferred to the inspection region through the substrate chuck.

The same fluid may be filled in both the assembly area 510 and the inspection area 520 . The substrate may be transferred from the assembly area to the inspection area while submerged in the fluid. When the substrate S disposed in the assembly region 510 is taken out of the fluid, the pre-assembled semiconductor light emitting device may be separated from the substrate due to surface energy between the fluid and the semiconductor light emitting device. For this reason, it is preferable that the substrate is transferred in a state immersed in the fluid.

The assembly chamber 500 may include a gate 530 configured to be movable up and down so that the substrate can be transferred in a state immersed in the fluid. As shown in FIG. 22 , the gate 530 maintains an elevated state (a first state) while self-assembly is in progress or a substrate inspection is in progress, so that the assembly region 510 and the inspection region of the assembly chamber 500 are The fluid contained in 520 isolates each other. The gate 530 separates the assembly region and the inspection region, thereby preventing the semiconductor light emitting device from moving to the inspection region during self-assembly and interfering with the inspection of the substrate.

When the substrate S is transferred, as shown in FIG. 23 , the gate 530 descends (a second state) to remove the boundary between the assembly area 510 and the inspection area 520 . Through this, the substrate chuck 200 can transfer the substrate from the assembly area 510 to the inspection area 520 only by horizontal movement without a separate vertical movement.

Meanwhile, a sonic generator for preventing aggregation of semiconductor light emitting devices may be disposed in the assembly region 510 . The sonic generator may prevent a plurality of semiconductor light emitting devices from aggregating with each other through vibration.

Meanwhile, the bottom surfaces of the assembly area 510 and the inspection area 520 may be made of a light-transmitting material. In one embodiment, referring to FIG. 20 , light transmitting areas 511 and 512 may be provided on the bottom surface of each of the assembly area 510 and the inspection area 520 . Through this, the present invention enables monitoring of the substrate during self-assembly or inspection of the substrate. Preferably, the area of the light-transmitting region is larger than the area of the assembly surface of the substrate. However, the present invention is not limited thereto, and the assembly chamber may be configured such that self-assembly and inspection are performed at the same location.

If the substrate chuck 200, the magnetic field generator 300 and the assembly chamber 500 described above are utilized, the self-assembly described with reference to FIGS. 8A to 8E can be performed. Hereinafter, a detailed structure and method for solving problems occurring during self-assembly will be described in detail.

First, the structure and method for solving the most core problems that occur during self-assembly will be described. Specifically for the problem, as the area of the display increases, the area of the assembly substrate increases. As the area of the assembly substrate increases, the bending phenomenon of the substrate increases. When self-assembly is performed in a curved state of the assembly substrate, since a magnetic field is not uniformly formed on the surface of the assembly substrate, it is difficult to stably perform self-assembly.

24 is a conceptual diagram illustrating a substrate bending phenomenon that occurs during self-assembly.

Referring to FIG. 24 , when the substrate S is maintained in a flat state during self-assembly, the distance between the plurality of magnets 313 and the substrate S becomes uniform. In this case, the magnetic field may be uniformly formed on the assembly surface of the substrate. However, when the substrate is actually loaded into the substrate chuck 200 , the substrate is bent due to gravity. In the bent state of the substrate (S'), the distance between the plurality of magnets 313 and the substrate (S') is not uniform, making it difficult to uniformly self-assemble. Since the magnetic field forming unit is disposed on the upper side of the substrate, it is difficult to arrange a separate mechanism for correcting the warpage of the substrate on the upper side of the substrate. In addition, when a separate mechanism for correcting the warpage of the substrate is disposed below the substrate, the movement of the semiconductor light emitting devices may be restricted, and a problem arises that the mechanism covers a part of the assembly surface. For this reason, it is difficult to arrange a mechanism for correcting the warpage of the substrate at either the upper side or the lower side of the substrate.

The present invention provides a structure and method of a substrate chuck for compensating for warpage of a substrate.

25 is a conceptual diagram illustrating a method for correcting warpage of a substrate.

Referring to FIG. 25 , after loading the substrate S′ on the substrate chuck 200 , when the assembly surface of the substrate faces the direction of gravity, the substrate S′ is bent. In order to minimize the bending of the substrate when loading the substrate, at least one of the first and second frames 210 and 220 provided in the substrate chuck applies pressure to all four corners of the rectangular substrate. Nevertheless, when the area of the substrate S' increases, the substrate is inevitably bent due to gravity.

As shown in the second figure of FIG. 25 , when the substrate chuck 200 moves to the assembly position and then descends a certain distance, the substrate S' comes into contact with the fluid F. In a state in which the substrate S' is simply in contact with the fluid F, the warpage of the substrate S' is not corrected. Although self-assembly can be made in the state shown in the second figure of FIG. 25, it is difficult to achieve uniform self-assembly.

In the present invention, in order to correct the warpage of the substrate, the substrate chuck 200 is further lowered while the substrate S' is in contact with the fluid F. At this time, the sealing part 212 provided in the first frame 210 prevents the fluid F from entering the window of the first frame. In addition, the side wall portion 210 ″ provided in the first frame 210 prevents the fluid F from overflowing the first frame and overflowing to the opposite surface of the assembly surface of the substrate S′.

Here, the sealing part 212 should be formed to surround all corners of the substrate. In addition, the height of the side wall portion 210 ″ should be greater than the depth at which the first frame 210 descends to the maximum based on the state in which the first frame 210 is in contact with the fluid F. That is, when the substrate chuck 200 is lowered, the fluid should not penetrate beyond the window and the side wall portion 210 ″ of the first frame 210 .

Due to the sealing part 212 and the side wall part 210 ″ described above, when the substrate chuck 200 descends, the surface of the fluid F rises. At this time, the buoyancy force by the fluid F acts on the substrate S'. As the surface rise width of the fluid F increases, the buoyancy force acting on the substrate S' increases.

In the present invention, the buoyancy force acting on the substrate varies by measuring the degree of warpage of the substrate S′ and adjusting the descending width of the substrate chuck 200 according to the degree of warpage of the substrate. When an appropriate buoyancy force is applied to the substrate, as shown in the third figure of FIG. 25 , the substrate is maintained in a flat state (S).

The magnetic field forming unit 300 is transferred to the upper side of the substrate S in a state in which buoyancy is applied to the substrate S, and then horizontally moves along the substrate S. At this time, the power of the power supply unit 171 is applied to the assembly electrode 161c through the electrode connection unit 213 . That is, the self-assembly proceeds in a state in which the buoyancy force is applied to the assembly surface of the substrate (S).

According to the above description, it is possible to correct the warpage of the substrate without the need to dispose separate structures on the upper and lower sides of the substrate. Through this, the present invention makes it possible to achieve a high self-assembly yield even when the area of the assembly substrate increases.

Meanwhile, according to the self-assembly method described above, the method includes contacting the substrate with a fluid, maintaining the substrate immersed in the fluid, and releasing the substrate from the fluid. In the three steps described above, factors that adversely affect the self-assembly yield may be generated. A structure of a substrate chuck capable of increasing self-assembly yield by solving problems that may occur in the above three steps will be described.

26 to 29 are perspective views of a substrate chuck according to an embodiment of the present invention, FIG. 30 is a perspective view showing a second frame and a frame transfer unit according to an embodiment of the present invention, and FIG. 31 is an embodiment of the present invention It is a side view showing the second frame and the frame transfer unit.

Since the substrate chuck according to the present invention may include all of the components described with reference to FIGS. 11 to 14 , a description of the contents described with reference to FIGS. 11 to 14 will be omitted.

First, the rotation unit 240 provided in the substrate chuck will be described.

26 to 29 , the rotation unit 240 basically serves to vertically invert the substrate. Due to the electric field formed on the assembled electrode during self-assembly, the semiconductor light emitting device remains fixed to the substrate, but when no voltage is applied to the assembled electrode, the semiconductor light emitting device is not fixed to the substrate.

Since the assembly surface of the substrate faces in the direction of gravity during self-assembly, if no voltage is applied to the assembly electrode when self-assembly is completed, the pre-assembled semiconductor light emitting device is separated from the substrate. 11 to 14 , since the voltage applied to the assembly electrode is transmitted through the substrate chuck, when the substrate is unloaded from the substrate chuck, the voltage is no longer applied to the assembly electrode. When the substrate is unloaded with the assembly surface of the substrate facing the direction of gravity, the pre-assembled semiconductor light emitting devices are separated from the substrate.

For the above reasons, when the substrate is unloaded after the self-assembly is finished, the assembly surface of the substrate must face the opposite direction of gravity. The rotation unit 240 serves to prevent the semiconductor light emitting device from being separated from the substrate by making the assembly surface of the substrate facing the direction of gravity to face the direction opposite to the direction of gravity.

The rotating part 240 includes a rotating shaft 241 . At least a portion of the substrate chuck 200 rotates about the rotation shaft 241 . The rotation shaft 241 formed on the substrate chuck 200 according to the present invention is disposed at a position spaced apart from the center of the substrate support part by a predetermined distance. More specifically, the rotation shaft 241 is located at the end of the substrate support.

In an embodiment, the rotation shaft 241 may be disposed on the fixing part 230 provided in the substrate chuck. The fixing part 230 may include a side wall part, and the rotation shaft 241 may be disposed at an end of the side wall part provided in the fixing part 230 .

When the substrate chuck 200 rotates about the rotation shaft 241 located at the end of the substrate support part, a state in which the substrate loaded on the substrate chuck 200 is disposed at an angle to the ground may be formed. The present invention improves the self-assembly yield by arranging the fluid surface and the substrate at an angle when the substrate and the substrate are brought into contact with the fluid and when the substrate is released from the fluid.

Specifically, in the present invention, when the substrate and the fluid are brought into contact, the rotation unit 240 provided in the substrate chuck 200 rotates only to a state in which the substrate is disposed obliquely to the surface of the fluid. Thereafter, the vertical movement unit provided in the substrate chuck 200 lowers the substrate chuck until one end of the substrate is in contact with the fluid. Thereafter, the rotating unit 240 rotates the substrate chuck so that the substrate sequentially contacts the fluid along one direction. When the rotation shaft 241 is disposed at the central portion instead of the end portion of the substrate support, the substrate cannot sequentially contact the fluid along one direction. The present invention allows the substrate to sequentially contact the fluid along one direction, so that the bubbles formed between the substrate and the fluid are pushed to the edge of the substrate and removed.

Meanwhile, after the self-assembly is completed, the rotating unit 240 rotates the substrate chuck 200 in a direction opposite to the direction in which the substrate is rotated when it comes into contact with the fluid. Accordingly, the substrate is released from the fluid in the same trajectory as when it comes into contact with the fluid. When the rotating part 240 is disposed at the center of the substrate support part, a portion of the substrate is additionally immersed in the fluid when the substrate chuck 200 is rotated, and in this process, the buoyancy force by the fluid is non-uniformly applied to the substrate. As a result, the substrate may be damaged. In the present invention, in order to prevent non-uniform buoyancy force from acting on the substrate while the substrate is separated from the fluid after the self-assembly is completed, the rotating shaft 240 is disposed at the end of the substrate support part.

As described above, according to the present invention, the rotating part of the substrate chuck is disposed at the end of the substrate support in order to solve the problem that occurs when the substrate is in contact with the fluid and the problem that occurs when the substrate is released from the fluid.

Hereinafter, a structure of a substrate chuck for solving a problem occurring in a state in which the substrate is immersed in a fluid will be described.

When the substrate is immersed in the fluid, a buoyancy force by the fluid is applied to the assembly surface of the substrate. 11 to 14 , the second frame 220 presses the substrate, and the substrate is in close contact with the sealing part 212 of the first frame 210 . Accordingly, even if a buoyant force acts on the assembly surface of the substrate, the fluid does not penetrate between the substrate and the first frame 210 .

However, since the buoyancy force due to the fluid continuously acts while the substrate is immersed in the fluid, when the sealing between the substrate and the first frame 210 is not complete, the fluid penetrates between the substrate and the first frame 210 . can do. For example, as the depth at which the substrate is immersed in the fluid increases, the buoyancy force acting on the substrate may increase. Due to this, the seal between the substrate and the first frame 210 may be temporarily broken.

Since the electrode connection part 213 is connected to the edge of the substrate, even a small amount of fluid can have a fatal effect on the self-assembly yield, and the substrate itself may be damaged.

The present invention has structures for preventing the substrate from being damaged by the buoyancy force acting on the substrate during self-assembly.

As described above, the present invention includes a frame moving unit that vertically moves at least one of the first and second frames. In one embodiment, referring to FIG. 29 , the motor 261 provided in the frame moving unit may be fixed to the fixing unit 230 to supply power to another part. 30 and 31 , the guide part 262 is connected to the second frame 220 . The guide part 262 receives power from the motor 261 to move the second frame 220 up and down. However, the present invention is not limited thereto, and a transfer means for vertically moving the first frame 210 may be provided.

The frame moving unit vertically moves at least one of the first and second frames 210 and 220 after the substrate is loaded between the first and second frames 210 and 220, and the first and second frames 210 and 220) press the substrate.

When the substrate is loaded, as described with reference to FIGS. 11 to 14 , at least one of the first and second frames 210 and 220 has a protrusion 211 for guiding the alignment position of the substrate so that the substrate is aligned at the correct position. ) can be formed.

After the substrate is aligned in the correct position by using the protrusion 211 , the frame moving unit vertically moves at least one of the first and second frames 210 and 220 . Accordingly, the sealing part 212 provided in the first frame 210 is in contact with the entire edge of one surface (the first surface) on which the assembly surface is located among both surfaces of the substrate, and the bottom portion provided in the second frame 220 is the substrate. Of the two sides of the , one side where the assembly side is located and the entire edge of the opposite side (the second side) are in contact. Referring to FIG. 30 , the bottom portion around the hole 220 ″″ formed in the second frame 220 is in contact with the entire second surface edge of the substrate.

Accordingly, the sealing part 212 provided on the first frame 210 is in close contact with the entire first surface edge of the substrate, and the second frame 220 presses the entire second surface edge of the substrate. In an embodiment, when the substrate has a rectangular plate shape, the sealing part 212 is disposed to surround all four corners of the substrate, and the second frame 220 covers all four corners of the substrate. made to pressurize.

In the present invention, by allowing the second frame 220 to press the entire edge of the substrate, the bending phenomenon of the substrate is primarily minimized and the fluid is prevented from penetrating between the substrate and the first frame 210 during self-assembly.

Furthermore, the present invention has an additional structure that can protect the substrate during self-assembly.

Specifically, referring to FIG. 29 , the present invention may further include an auxiliary clamp 270 for fixing the second frame 220 while the second frame 220 presses the substrate. The auxiliary clamp 270 may be disposed on a sidewall of the fixing unit 230 .

The auxiliary clamp 270 may be configured to additionally press at least one of the second frame 220 and the edge of the substrate while the second frame 220 presses the substrate by the frame moving unit.

In an embodiment, the auxiliary clamp 270 may have a cylindrical structure. The auxiliary clamp 270 of the cylinder structure is made to be stretchable while being fixed to the sidewall of the fixing part 230 , and extends in the direction of the substrate while the substrate is pressed by the second frame 220 to the second frame ( 220) and at least one of the substrate is additionally pressed. However, the auxiliary clamp 270 is not limited thereto.

The frame moving unit and the auxiliary clamp utilize a known means capable of inducing vertical movement of the object, but each of the frame moving unit and the auxiliary clamp is preferably made of different means. This is to enable the other to maintain a sealing state between the substrate and the first frame 210 even if a functional problem occurs in any one of the frame moving part and the auxiliary clamp during self-assembly.

For example, the frame moving unit may be a vertical movement device using a servo motor, and the auxiliary clamp may be a vertical movement device using a cylinder. However, the present invention is not limited thereto.

Meanwhile, at least one of the frame moving unit and the auxiliary clamp may increase the pressure for pressing the substrate in proportion to the depth at which the substrate is immersed in the fluid. For example, the frame moving unit may increase the pressure for pressing the substrate in proportion to the depth at which the substrate is additionally descended based on the state in which the substrate is in contact with the fluid.

As described above, the present invention prevents a phenomenon in which the substrate is damaged due to the buoyancy force acting on the substrate during self-assembly.

Additionally, a device capable of sensing the degree of warpage of the substrate may be disposed on the substrate chuck 200 . Specifically, referring to FIG. 29 , a sensor module 280 configured to measure a distance to a measurement target is disposed in the fixing unit 230 .

The sensor module 280 includes a displacement sensor 281 and sensor transfer units 282 and 283 .

The displacement sensor 281 is moved by the sensor transfer units 282 and 283 disposed on the side wall of the fixing unit. The sensor transfer units 282 and 283 allow the displacement sensor 281 to move in the X and Y-axis directions, respectively. The displacement sensor 281 horizontally moves the substrate with respect to the reference plane defined by the sensor transfer units 282 and 283 and measures the distance between the substrate and the displacement sensor.

As described above, the substrate chuck 200 according to the present invention not only serves to support and transport the substrate, but also improves the self-assembly yield and prevents the substrate from being damaged.

Claims (10)

A substrate chuck for seating a semiconductor light emitting device dispersed in a fluid at a predetermined position on a substrate, the substrate chuck comprising:
a substrate support configured to support a substrate having assembly electrodes;
a vertical movement unit for lowering the substrate so that one surface of the substrate is in contact with the fluid in a state in which the substrate is supported;
an electrode connection unit for generating an electric field by applying power to the assembled electrode so that the semiconductor light emitting devices are seated at a predetermined position on the substrate while the semiconductor light emitting devices are moved by a change in the position of the magnets; and
and a rotation unit for rotating the substrate support unit about a rotation axis so that the substrate faces in an upward direction or a downward direction;
The substrate support includes first and second frames for fixing the substrate in the vertical direction,
Each of the first and second frames may include a bottom portion in contact with the substrate; and
It is disposed in the center of the bottom portion and has a hole for exposing one surface of the substrate to the outside,
The substrate chuck is characterized in that the rotation shaft is located at an end of the substrate support portion spaced a predetermined distance from the center of the substrate support portion. delete According to claim 1,
The substrate support portion may include: a side wall portion; and
and a fixing part for fixing the first and second frames;
The rotation shaft is a substrate chuck, characterized in that disposed at one end of the side wall portion of the fixing portion. 4. The method of claim 3,
It is disposed on the fixed part, and a frame moving part for vertically moving the second frame,
The frame moving unit vertically moves at least one of the first and second frames so that the first and second frames press the substrate while the substrate is loaded. 4. The method of claim 3,
The substrate chuck according to claim 1, wherein a protrusion for guiding an alignment position of the substrate is formed on at least one of the first and second frames. delete A substrate chuck for seating a semiconductor light emitting device dispersed in a fluid at a predetermined position on a substrate, the substrate chuck comprising:
a substrate support configured to support a substrate having assembly electrodes;
a vertical movement unit for lowering the substrate so that one surface of the substrate is in contact with the fluid in a state in which the substrate is supported;
an electrode connection unit for generating an electric field by applying power to the assembled electrode so that the semiconductor light emitting devices are seated at a predetermined position on the substrate while the semiconductor light emitting devices are moved by a change in the position of the magnets; and
and a rotation unit for rotating the substrate support unit about a rotation axis so that the substrate faces in an upward direction or a downward direction;
The substrate support includes first and second frames for fixing the substrate in the vertical direction,
Each of the first and second frames may include a bottom portion in contact with the substrate; and
It is disposed in the center of the bottom portion and has a hole for exposing one surface of the substrate to the outside,
In a state in which the first and second frames press the substrate, the bottom portion of the second frame is formed to be in contact with the entire edge of one of both surfaces of the substrate. 8. The method of claim 7,
Further comprising a sealing portion disposed on the bottom provided in the first frame,
The substrate chuck according to claim 1, wherein the sealing portion is formed to contact the entire edge of the other one of both surfaces of the substrate in a state in which the first and second frames press the substrate. 5. The method of claim 4,
and an auxiliary clamp for fixing at least one of the second frame and the substrate while the second frame presses the substrate. 5. The method of claim 4,
a displacement sensor disposed on the fixing unit and configured to measure a distance to a measurement target object; and
The substrate chuck according to claim 1, further comprising a sensor transfer unit disposed on a sidewall of the fixing unit and horizontally moving the displacement sensor with respect to the substrate.

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