KR20220120642A - Method for manufacturing a display device using a semiconductor light emitting device - Google Patents

Abstract

A method of manufacturing a display device according to the present invention includes the steps of: (a) putting semiconductor light emitting devices in a first chamber containing a fluid, and transferring a substrate to an upper part of the first chamber; (b) using an electric field and a magnetic field to seat the semiconductor light emitting devices at predetermined positions on the substrate; (c) disposing a fluid ejection module including a nozzle hole in a second chamber containing a fluid, and transferring the substrate on which the semiconductor light emitting devices are assembled to an upper portion of the second chamber; (d) aligning the fluid ejection module so that the nozzle hole faces a region that does not correspond to a preset position of the substrate; and (e) continuously injecting a fluid onto the substrate while moving the fluid ejection module.

Description

Method for manufacturing a display device using a semiconductor light emitting device

The present invention relates to a method of manufacturing a display device using a semiconductor light emitting device having a size of several to several tens of μm.

For this purpose, a liquid crystal display (LCD), an organic light emitting diode display (OLED), and a micro LED display are competing.

Among them, a display using a semiconductor light emitting device (micro LED) having a diameter or cross-sectional area of 100 μm or less can provide very high efficiency because it does not absorb light using a polarizing plate or the like.

However, since the micro LED display requires millions of semiconductor light emitting devices to implement a large area, it is difficult to transfer the devices compared to other technologies.

The technologies currently being developed for the transfer process of micro LED 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.

An object of the present invention is to provide a method of manufacturing a display device with improved mass productivity and productivity. In particular, it is an object of the present invention to provide a repair process for efficiently removing semiconductor light emitting devices erroneously assembled on a substrate.

A method of manufacturing a display device according to the present invention includes the steps of: (a) putting semiconductor light emitting devices in a first chamber containing a fluid, and transferring a substrate to an upper part of the first chamber; (b) using an electric field and a magnetic field to seat the semiconductor light emitting devices at predetermined positions on the substrate; (c) disposing a fluid ejection module including a nozzle hole in a second chamber containing a fluid, and transferring the substrate on which the semiconductor light emitting devices are assembled to an upper portion of the second chamber; (d) aligning the fluid ejection module so that the nozzle hole faces a region that does not correspond to a preset position of the substrate; and (e) continuously injecting a fluid onto the substrate while moving the fluid ejection module.

According to the present invention, the fluid dispensing module comprises: a fluid supply unit for supplying a fluid; a housing part connected to the fluid supply part and including an accommodating space in which the fluid supplied from the fluid supply part is accommodated; and a nozzle hole formed on one surface of the housing part and configured to spray the fluid accommodated in the accommodation space toward the substrate.

According to the present invention, the substrate includes: a base; assembly electrodes extending in one direction and formed on the base part; a dielectric layer formed to cover the assembly electrodes; and a barrier rib portion stacked on the dielectric layer while forming cells in which the semiconductor light emitting device is mounted along an extension direction of the assembly electrodes.

According to the present invention, the step (e) may include: vertically moving the fluid ejection module so that the fluid ejection module and the substrate are at a preset distance; and horizontally moving the fluid ejection module while maintaining the preset interval.

According to the present invention, the fluid ejection module is horizontally moved by using a direction crossing the extension direction of the assembled electrodes as a main movement path.

According to the present invention, the step (d) is characterized in that the fluid ejection module is aligned so that the nozzle hole faces the partition wall between adjacent cells in the extending direction of the assembled electrodes.

According to the present invention, the first chamber and the second chamber are arranged side by side with a gate interposed therebetween, and in step (c), when the gate is opened, the substrate disposed on the first chamber is transferred to the upper part of the second chamber. It is characterized in that it moves horizontally.

According to the present invention, while the steps (b) to (e) proceed, a voltage is continuously applied to the assembled electrodes.

According to the present invention, while the steps (a) to (e) are in progress, the inside of the first and second chambers are continuously monitored, and the steps (d) and (e) are optional according to the contents of the monitoring. It is characterized in that it proceeds with

According to the present invention, in the step (e), the moving direction, the moving speed, and the intensity of the fluid injected through the nozzle hole are adjusted according to the monitoring contents.

The present invention has the effect of reducing the time required to remove the semiconductor light emitting devices erroneously assembled on the substrate, thereby reducing the tack time, and improving the mass productivity and productivity of the display device.

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 .
10A to 10E are conceptual views for explaining a method of manufacturing a display device according to the present invention.
11 is a view showing assembly types that occur during self-assembly.
12 is a view showing the structure of the fluid ejection module according to the present invention.
13 is a view showing the first and second chambers ((a): gate closed state, (b): gate open state) according to the present invention.
14 is a view for explaining the path of the fluid injection module according to 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 a meaning or role distinct from each other by themselves. In addition, in describing the embodiments disclosed in this 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, 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 in the present specification by the accompanying drawings.

Also, when an element, such as a layer, region, or substrate, is referred to as being “on” another component, it may be understood that it is directly on the other element or intervening elements may be present therebetween. 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. (slate PC), tablet PC (tablet PC), ultrabook (ultrabook), digital TV (digital TV), desktop computer (desktop computer) and the like may be included. However, the configuration according to the embodiment described in this specification can be applied as long as it can include a display 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 partially enlarged view of a portion 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 the edge of the display module 140 may form a bezel of the display device 100 .

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 is 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 the 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 μm or less. In the semiconductor light emitting device 150 , blue, red, and green colors are respectively provided in the light emitting region, 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 added with indium (In) and/or aluminum (Al) to be implemented as a high power light emitting device that emits various lights including blue. can

The vertical semiconductor light emitting device 150 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 An n-type semiconductor layer 153 formed on the 154 and an n-type electrode 152 formed on the n-type semiconductor layer 153 are included. In this case, the lower p-type electrode 156 may be electrically connected to the p-electrode of the wiring board 110 , and the upper n-type electrode 152 may be electrically connected to the n-electrode and the n-type electrode 152 on the upper side of the semiconductor light emitting device 150 . can be electrically connected. 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.

As an example, the semiconductor light emitting device 250 includes a p-type electrode 256 , a p-type semiconductor layer 255 on which the p-type electrode 256 is formed, and an active layer 254 formed on the p-type semiconductor layer 255 . , an n-type semiconductor layer 253 formed on the active layer 254 and an n-type electrode 252 spaced apart from the p-type electrode 256 in the horizontal direction on the n-type semiconductor layer 253 . In this case, both the p-type electrode 256 and the n-type electrode 252 may be electrically connected to the p-electrode and the n-electrode of the wiring board 110 under the semiconductor light emitting device 250 .

The vertical semiconductor light emitting device 150 and the horizontal semiconductor light emitting device 250 may be a green semiconductor light emitting device, a blue semiconductor light emitting device, and 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 be implemented as a high power light emitting device that emits green or blue light. can 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.

In addition, 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.

Meanwhile, referring to FIGS. 1 to 4 , since the light emitting diodes are very small, the unit pixels emitting light on the display panel can be arranged with a high definition, 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 & place method as such a transfer technology, but the success rate is low and it takes a lot of time. As another example, there is a technique of transferring several devices at a time using a stamp or a roll, but it is not suitable for a large screen display because of a limitation in yield.

The present invention proposes a new manufacturing method and manufacturing apparatus of a display device that can solve these problems.

To this end, first, a new method of manufacturing a display device will be described. 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, a method of self-assembling a horizontal semiconductor light emitting device is exemplified below, but this 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 layer is grown on the active layer 154 . Grow (155). 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, the first conductivity type semiconductor layer 153 and the active layer are sequentially grown as shown in FIG. 5A. (154) and the second conductivity type 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 present embodiment exemplifies a case in which the active layer 154 is present, a structure in which the active layer 154 is not present is also possible in some cases as described above. For this example, 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 of the p-type semiconductor layer.

The growth substrate 159 (wafer) may be formed of a light-transmitting material, for example, sapphire (Al ₂ O ₃ ), GaN, ZnO, or AlO, but is not limited thereto. In addition, the growth substrate 159 may be formed of a material suitable for semiconductor material growth (carrier wafer) or a material having excellent thermal conductivity. The growth substrate 159 includes a conductive substrate or an insulating substrate, for example, a sapphire (Al ₂ O ₃ ) SiC substrate having high thermal conductivity compared to the substrate or at least one of Si, GaAs, GaP, InP, and Ga ₂ O ₃ . 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 a plurality of semiconductor 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.

If a horizontal type semiconductor light emitting device is formed, the active layer 154 and the second conductivity type semiconductor layer 155 are partially removed in the vertical direction to expose the first conductivity type semiconductor layer 153 to the outside. After the mesa process, the first conductive type semiconductor layer 153 is etched to form a plurality of semiconductor light emitting device arrays, and isolation 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 conductivity type electrode 156 may be formed by a deposition method such as sputtering, but is not limited thereto. However, when the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer are the n-type semiconductor layer and the p-type semiconductor layer, respectively, the second conductivity-type 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 159 may be removed using a laser lift-off method (LLO) or a chemical lift-off method (CLO) ( FIG. 5D ).

Thereafter, a step of seating 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 150 are self-assembled on the substrate using flow, gravity, surface tension, and the like. In this case, the substrate may be an assembly substrate 161 .

As another example, it is also possible to place the wiring board in a fluid chamber instead of the assembly board 161 to directly seat the semiconductor light emitting devices 150 on the wiring board. However, for convenience of description, in the present invention, the substrate is provided as the assembly substrate 161 to exemplify that the semiconductor light emitting devices 150 are seated.

Cells (not shown) in which the semiconductor light emitting devices 150 are inserted may be provided on the assembly substrate 161 so that the semiconductor light emitting devices 150 can be easily mounted 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 the plurality of semiconductor light emitting devices 150 are seated on the assembly substrate 161 , the semiconductor light emitting devices 150 of the assembly substrate 161 are transferred to the wiring board, thereby enabling large-area transfer. 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 using an electric field during the movement process. Hereinafter, such a transfer method and apparatus will be described in more detail with reference to 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 . In addition, FIGS. 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 , and FIG. 9 is a conceptual diagram for explaining the semiconductor light emitting device of FIGS. 8A to 8E .

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

The fluid 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 fluid 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 fluid chamber 162 may be of a closed type in which the space is a closed space.

The fluid chamber 162 may be disposed such that an assembly surface of the substrate 161 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 controlled by a 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 fluid chamber 162 . As shown, the assembly surface of the substrate 161 is disposed to be immersed in the fluid in the fluid 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 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 may be made of an inorganic material such as SiO ₂ , SiN _x , SiON, Al ₂ O ₃ , TiO _{2 ,} HfO ₂ . Alternatively, the dielectric layer 161b may be formed of a single layer or a multi-layer as an organic insulator. The thickness of the dielectric layer 161b may be in the range 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.

The cells 161d have grooves for accommodating the semiconductor light emitting devices 150 , and the grooves may be spaces defined by the barrier ribs 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, when the semiconductor light emitting device has a circular shape, the grooves formed in the cells may be circular. Furthermore, each of the cells 161d 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 161b may cover the plurality of electrodes 161c and the dielectric layer 161b may form the bottom of the cells 161d. 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 a semiconductor light emitting device can be inserted into the cells 161d by the electric field. .

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 161c 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 150 . The magnet 163 is spaced apart from the fluid 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 163 is controlled by the position control unit 164 connected to the magnet 163 . .

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

Referring to FIG. 9 , a semiconductor light emitting device 1050 including a magnetic material has a first conductivity type electrode 1052 , a second conductivity type electrode 1056 , and a first conductivity type electrode 1052 on which the first conductivity type electrode 1052 is disposed. A type semiconductor layer 1053 , a second conductivity type semiconductor layer 1055 overlapping the first conductivity type semiconductor layer 1053 , the second conductivity type electrode 1056 is disposed, and the first and second An active layer 1054 disposed between the conductive semiconductor layers 1053 and 1055 may be included.

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 an active layer may be used.

Meanwhile, in the present invention, the first conductivity type electrode 1052 may be generated after the semiconductor light emitting device 1050 is assembled on a wiring board by self-assembly or the like. Also, in the present invention, the second conductivity type electrode 1056 may include a 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 in the second conductive type 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 conductivity type electrode 1056 of the semiconductor light emitting device 1050 may include a first layer 1056a and a second layer 1056b, where the first The first layer 1056a may include a magnetic material, and the second layer 1056b may include a metal material rather than a magnetic material.

In this example, the first layer 1056a including a magnetic material may be disposed to contact the second conductivity-type 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 , and the second layer 1056b may be a contact metal connected to the wiring of the wiring board. have. 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 1053 .

Referring back to FIGS. 6 and 7 , 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 fluid chamber 162 or rotates the magnet 163 . It can be provided with a motor that can make it. 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 fluid 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 fluid 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 can be 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. have. 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, a magnetic material may be deposited in the process of forming the second conductivity type electrode of FIG. 5C .

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

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

In this case, some of the semiconductor light emitting devices 1050 may sink to the bottom of the fluid chamber 162 , and some may float in the fluid. When the light-transmitting bottom plate 166 is provided in the fluid 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 float in a vertical direction in the fluid 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 fluid chamber 162 . As another example, the magnet 163 may be configured as an electromagnet, and 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 may be controlled using the weight, buoyancy, and magnetic force of the semiconductor light emitting devices 1050 . The separation distance may be several mm to several tens of μm 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 fluid chamber 162 . For example, the magnet 163 is moved in a horizontal direction, clockwise or counterclockwise direction with the substrate 161 ( 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, a step of inducing the semiconductor light emitting devices 1050 to the predetermined position by applying an electric field to be seated at a predetermined position of the substrate 161 while the semiconductor light emitting devices 1050 are moved is performed. becomes (Fig. 8c).

For example, the semiconductor light emitting devices 1050 move in a direction perpendicular to the substrate 161 by the electric field while the semiconductor light emitting devices 1050 are moving in a horizontal direction to the substrate 161 . 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 using this, assembly is induced only at a preset position. That is, the semiconductor light emitting devices 1050 are self-assembled at the assembly position of the substrate 161 using the selectively generated electric field. To this end, cells in which the semiconductor light emitting devices 1050 are inserted may be provided on the substrate 161 .

After that, the unloading process of the substrate 161 is performed, and the assembly process is completed. When the substrate 161 is an assembly substrate, as described above, a post-process for realizing a display device in which the arrayed semiconductor light emitting devices are transferred to a wiring substrate may be performed.

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

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

The self-assembly apparatus and method described above use a magnetic field to concentrate distant parts near a predetermined assembly site in order to increase the assembly yield in fluidic assembly, and apply a separate electric field to the assembly site to selectively parts only at the assembly site. to be assembled. At this time, the assembly substrate 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 influence of gravity or frictional force and prevent non-specific binding.

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

As described above, according to the present invention, it is possible to convert a semiconductor light emitting device into a large amount of pixels 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.

Hereinafter, a method of manufacturing a new display device will be described.

The present invention relates to a method of manufacturing a display device with improved mass productivity and productivity, and in particular, the present invention is characterized by a repair process performed after self-assembly.

10A to 10E are conceptual views for explaining a method of manufacturing a display device according to the present invention.

First, the steps of (a) putting the semiconductor light emitting devices 500 into the first chamber 200 containing the fluid, and transferring the substrate 400 to the upper part of the first chamber 200 may be performed (FIG. 10A). ).

In the present invention, the first chamber 200 may be a chamber in which self-assembly is performed. The first chamber 200 may be an open type water tank with an open top, and may be formed of a transparent material so that the inside can be seen from the outside. In addition, DI water (deionized water) or a fluid to which a surfactant is added may be accommodated in the first chamber 200 as an assembly solution, but the present invention is not limited thereto.

The semiconductor light emitting devices 500 injected into the first chamber 200 may be self-assembly semiconductor light emitting devices. Accordingly, the semiconductor light emitting devices 500 injected into the first chamber 200 may have a symmetrical structure including a magnetic material.

The substrate 400 may be transferred to the open upper part of the first chamber 200 and disposed to be immersed in the fluid contained in the first chamber 200 . At this time, at least the assembly surface of the substrate 400 may be disposed to be immersed in the fluid. The assembly surface of the substrate 400 may be a surface on which structures for self-assembly are formed, which will be described later. According to the present invention, the substrate 400 may be fixed to the substrate chuck 600 and transferred to the upper portion of the first chamber 200 .

Next, (b) using an electric field and a magnetic field to seat the semiconductor light emitting devices 500 at a preset position of the substrate 400 may be performed ( FIG. 10B ).

This step may correspond to the self-assembly step according to FIGS. 8A to 8E . In this step, a magnet or a magnet array may be provided on the opposite side of the assembly surface of the substrate 400 to form a magnetic field. The semiconductor light emitting devices 500 may be guided around the substrate 400 on which a magnetic field is formed by a magnetic material.

Also, in this step, the substrate 400 may include assembly electrodes 420 on the assembly surface to form an electric field.

The substrate 400 may include a base portion 410 , assembly electrodes 420 , a dielectric layer 430 , a cell 440 , and a partition wall portion 450 .

The base part 410 may include sapphire, glass, silicon, or the like, or polyimide (PI) to implement flexibility. However, the present invention is not limited thereto, and any material having insulation and flexibility may be used. In addition, the base part 410 may be made of a transparent material or an opaque material.

The assembly electrodes 420 may be line-shaped electrodes extending in one direction. The assembly electrodes 420 may be formed of a plurality of lines and disposed on the base portion 410 at predetermined intervals. A voltage may be applied to the assembly electrodes 420 , and through this, an electric field may be formed on the assembly surface of the substrate 400 .

The dielectric layer 430 may be formed to cover the assembly electrodes 420 . The dielectric layer 430 may be formed of an inorganic material such as SiO ₂ , SiN _x , Al ₂ O ₃ , TiO ₂ , or HfO ₂ .

Also, a barrier rib part 450 may be formed on the dielectric layer 430 . The barrier rib part 450 may be stacked on the dielectric layer 430 while forming the cells 440 in which the semiconductor light emitting device 500 is mounted along the extending direction of the assembly electrodes 420 . The barrier rib part 450 may be formed of a polymer material such as PAC or PI or an inorganic material such as SiO ₂ and SiN _x .

The cells 440 may be formed to overlap the assembly electrodes 420 . Accordingly, when a voltage is applied to the assembly electrodes 420 , an electric field is relatively strong inside the cells 440 , so that the semiconductor light emitting device 500 can be induced and seated inside the cells 440 . The semiconductor light emitting device 500 seated in the cell 440 may be held inside the cell 440 by an electric field, and voltage may be continuously applied to the assembled electrodes 420 while the steps to be described below are performed. have.

That is, while the assembly surface of the substrate 400 is disposed to face the bottom surface of the first or second chamber, the assembly electrodes 420 to hold the semiconductor light emitting devices 500 to the assembly surface of the substrate 400 . ) may be continuously applied with voltage.

Next, (c) the fluid injection module 700 including the nozzle hole 730 is disposed in the second chamber 300 containing the fluid, and the semiconductor light emitting devices 500 are placed on the second chamber 300 . A step of transferring the assembled substrate 400 may be performed ( FIG. 10C ).

In the present invention, the second chamber 300 may be a chamber in which a repair process is performed.

11 is a view showing assembly types that occur during self-assembly.

Referring to FIG. 11 , through self-assembly, most of the semiconductor light emitting devices 500 may be accurately seated in the cell 440 as shown in FIG. 11A . However, some of the semiconductor light emitting devices 500 ′ are not seated accurately in the cell 440 as shown in FIGS. 11 ( b ) to 11 ( d ) and are stuck in the barrier rib part 450 , or the cell 440 . It may be seated on the barrier rib part 450 by an electric field leaking to the outside, or may be seated on the cell 440 in a vertically inverted state.

The repair process corresponds to a process for separating the mis-assembled semiconductor light emitting devices 500 from the substrate 400 . In the present invention, a repair process of injecting a fluid onto the assembly surface of the substrate 400 may be performed, and details related thereto will be described later.

Meanwhile, like the first chamber 200 , the second chamber 300 may be an open type water tank with an open top, and may be formed of a transparent material so that the inside can be seen from the outside. In addition, a fluid such as DI water (deionized water) may be accommodated in the second chamber 300 , but the present invention is not limited thereto.

13 is a view showing the first and second chambers ((a): gate closed state, (b): gate open state) according to the present invention.

When self-assembly is completed, the substrate 400 may be transferred from the first chamber 200 to the second chamber 300 . According to an embodiment, the first chamber 200 and the second chamber 300 may be arranged side by side with a gate interposed therebetween as shown in FIG. 13 . The first chamber 200 and the second chamber 300 may be disposed with a wall interposed therebetween, and a portion of the wall may correspond to a gate. The substrate 400 may be horizontally transferred from the upper part of the first chamber 200 to the upper part of the second chamber 300 by opening a gate. In detail, after separating the substrate 400 immersed in the fluid in the first chamber 200 from the fluid, it is placed in the upper part of the second chamber 300 through horizontal movement, and again in the fluid contained in the second chamber 300 . It can be placed to be partially submerged. In this case, the substrate 400 may be transferred while being fixed to the substrate chuck 600 .

The fluid ejection module 700 may be disposed in the second chamber 300 in which the repair process is performed to remove the misassembled semiconductor light emitting devices 500 . The fluid ejection module 700 may be disposed to be completely submerged in the fluid accommodated in the second chamber 300 .

12 is a view showing the structure of the fluid ejection module according to the present invention.

Referring to FIG. 12 , the fluid dispensing module 700 may include a fluid supply unit 710 , a housing unit 720 , and a nozzle hole 730 .

The fluid supply unit 710 may be connected to one side of the housing unit 720 to supply a fluid to the accommodation space 724 in the housing unit 720 . The fluid supply unit 710 may be designed to supply an external fluid to the accommodation space 724 or a fluid in the second chamber 300 . Also, as an embodiment, the fluid supply unit 210 may be in the form of a tube (tube), and may communicate with the accommodation space 724 through the guide unit 723 formed on one side of the housing unit 720 .

The housing unit 720 has an accommodation space 724 in which the fluid supplied from the fluid supply unit 710 can temporarily stay, and may include an upper plate 721 and a lower plate 722 . The upper plate 721 may mean one surface of the substrate 400 side, and the lower plate 722 may refer to one surface of the bottom surface of the second chamber 300 , and the upper plate 721 and the lower plate 722 are made of glass. It may be formed of a transparent material.

The nozzle hole 730 may be formed in the upper plate 721 of the housing unit 720 , and the nozzle hole 730 may spray the fluid supplied from the fluid supply unit 710 toward the assembly surface of the substrate 400 . have.

The nozzle hole 730 may be formed in the upper plate 721 of the housing unit 720 through dry etching or laser processing. At this time, the nozzle hole 730 may be patterned in a circular shape having a diameter of several tens to hundreds of μm, preferably 25 to 100 μm in diameter. However, the shape and diameter (or length) of the nozzle hole 730 are not limited thereto.

In addition, although not separately shown in the drawing, the fluid ejection module 700 is configured to align the position of the fluid ejection module 700 with the control unit for controlling the driving of the fluid ejection module 700 and to move the fluid ejection module 700 . It may include a transfer unit.

Next, (d) aligning the fluid ejection module 700 so that the nozzle hole 730 faces a region that does not correspond to a preset position of the substrate 400 may be performed ( FIG. 10D ). That is, through this step, the nozzle hole 730 may be aligned to face a region other than the cell 440 of the substrate 400 , and the region may correspond to the upper surface of the partition wall part 450 .

For example, the fluid ejection module 700 may be aligned such that the nozzle hole 730 faces the partition wall 450 between adjacent cells 440 in the extending direction of the assembly electrodes 420 . Preferably, the fluid injection module 700 may be aligned to face the central portion of the upper surface of the partition wall portion 450 formed between the cells 440 , and at this time, from the nozzle hole 730 to the cells 440 on both sides The fluid ejection module 700 may be aligned so that the distance is within 200 μm. The alignment of the fluid ejection module 700 may be controlled by a controller.

The alignment of the nozzle holes 730 is to inject the fluid over a wider area rather than the specific cell 440 , and thus the repair process time can be shortened.

For example, the nozzle hole 730 may be aligned with respect to the cell 440 including the erroneously assembled semiconductor light emitting device 500 ′. In this case, the fluid injected from the nozzle hole 730 should not affect the surrounding cells 440 including the normally assembled semiconductor light emitting device 500 . Therefore, in this case, the repair process must be performed for each cell 440 .

Specifically, in this case, after aligning the fluid injection module 700 under the cell 440 including the erroneously assembled semiconductor light emitting device 500 ′, the fluid is directed toward the erroneously assembled semiconductor light emitting device 500 ′. will be sprayed In addition, between the nozzle hole 730 and the assembly surface of the substrate 400 so that the influence of the fluid injected through the nozzle hole 730 does not reach the cell 440 including the normally assembled semiconductor light emitting device 500 around it. spacing should be minimized. For example, the end of the nozzle hole 730 should be disposed so that the distance from the assembly surface of the substrate 400 is within several tens of μm.

However, as in the present invention, when the nozzle hole 730 is disposed to face a region other than the cell 440 , the fluid injected through the nozzle hole 730 may cause a plurality of cells 440 adjacent to the nozzle hole 730 . , and thus the time required for the repair process may be reduced. Details related thereto will be described later.

Finally, (e) a step of continuously injecting a fluid with respect to the substrate 400 while moving the fluid ejection module 700 may be performed ( FIG. 10E ).

This step includes the steps of vertically moving the fluid dispensing module 700 so that the fluid dispensing module 700 and the substrate 400 are at a preset distance, and horizontally moving the fluid dispensing module 700 while maintaining the preset distance It may include the step of

First, the step of vertically moving the fluid ejection module 700 and the substrate 400 so that the fluid ejection module 700 and the substrate 400 are at a preset distance may be performed. In this step, the fluid injection module 700 may be vertically moved so that the distance between the end of the nozzle hole 730 and the assembly surface of the substrate 400 is within several mm, and preferably, the distance is within 2 mm. The fluid ejection module 700 may be vertically moved as much as possible.

According to the present invention, since the repair process is performed in a scan format, the substrate ( A distance between the 400 and the fluid ejection module 700 may be determined with ease.

Next, the step of horizontally moving the fluid ejection module 700 while maintaining the preset interval may be performed.

14 is a view for explaining the path of the fluid injection module according to the present invention. For example, in this step, the fluid ejection module 700 may be horizontally moved by using a direction crossing the extension direction of the assembly electrodes 420 as a main movement path. In another embodiment, it is possible to horizontally move the assembly electrodes 420 in the same direction as the extension direction as the main movement path, but in this case, the distance between the nozzle hole 730 and the cells 440 is increased.

In the present invention, the fluid ejection module 700 may move in an aligned state such that the nozzle hole 730 always faces the cell 440 and the region between the cell 440 . At this time, the fluid injected from the nozzle hole 730 may be directed toward the cells 440 located on both sides of the main movement path.

Since the semiconductor light emitting devices 500 ′ misassembled as shown in FIGS. 11 ( b ) to 11 ( d ) are less affected by the electric field formed on the assembly surface of the substrate 400 , they are easily affected by the fluid on the substrate ( 400) can be removed.

In the present invention, in consideration of this point, after aligning the nozzle holes 730 to face the area between the cells 440 , the fluid is continuously sprayed while moving the fluid injection module 700 , and through this, erroneous assembly in a short time The semiconductor light emitting devices 500 ′ may be removed from the substrate 400 .

In this step, the fluid ejection module 700 may be horizontally moved at a constant speed, and the fluid may be continuously ejected in the process of moving the fluid ejection module 700 . Accordingly, since the position of the fluid injection module 700 with respect to each cell 440 is changed in real time, the fluid may be injected into each cell 440 at various angles.

According to the repair process according to the present invention, there is no need to align the nozzle hole 730 with respect to the region where the semiconductor light emitting device 500 is incorrectly assembled for fluid injection, and the fluid is sprayed (scan method) while continuously moving. Therefore, the time required for the repair process is shortened, and thus an efficient repair process can be performed.

In the present invention, while steps (a) to (e) are performed, the inside of the first and second chambers 200 and 300 may be continuously monitored. In particular, the assembly surface of the substrate 400 that is self-assembled and repaired through the interior of the first and second chambers 200 and 300 may be continuously monitored.

To this end, the first and second chambers 200 and 300 may be formed of a transparent material, or at least the bottom surface may be formed of a transparent material so that the assembly surface of the substrate 400 can be monitored. A configuration for monitoring 200 and 300 may be disposed below the bottom surface of the first and second chambers 200 and 300 . An image sensor may be provided as a configuration for monitoring the first and second chambers 200 and 300 , and through this, an image or an image of the assembly surface of the substrate 400 may be acquired.

On the other hand, some repair processes may be further selectively performed according to monitoring contents. For example, when there is a region in which the semiconductor light emitting device 500 ′ misassembled according to the monitoring content is not removed, the fluid is transferred while aligning the fluid ejection module 700 and the fluid ejection module 700 is moved. The spraying step (steps (d) and (e)) may be additionally performed.

In addition, the moving direction, the moving speed, and the intensity of the fluid injected through the nozzle hole 730 may be adjusted according to the monitoring contents.

As described above, the present invention can reduce the time required to remove the semiconductor light emitting devices 500 ′ misassembled on the substrate 400 , thereby reducing the tact time, and improving the mass productivity and productivity of the display device. can have an effect.

Claims (10)

(a) putting the semiconductor light emitting devices in the first chamber containing the fluid, and transferring the substrate to the upper part of the first chamber;
(b) using an electric field and a magnetic field to seat the semiconductor light emitting devices at predetermined positions on the substrate;
(c) disposing a fluid ejection module including a nozzle hole in a second chamber containing a fluid, and transferring the substrate on which the semiconductor light emitting devices are assembled to an upper portion of the second chamber;
(d) aligning the fluid ejection module so that the nozzle hole faces a region that does not correspond to a preset position of the substrate; and
(e) continuously injecting a fluid to the substrate while moving the fluid ejection module, a method of manufacturing a display device. According to claim 1,
The fluid dispensing module may include a fluid supply unit for supplying a fluid;
a housing part connected to the fluid supply part and including an accommodating space in which the fluid supplied from the fluid supply part is accommodated; and
and a nozzle hole formed on one surface of the housing part and configured to spray the fluid accommodated in the accommodation space toward the substrate. According to claim 1,
The substrate may include a base portion;
assembly electrodes extending in one direction and formed on the base part;
a dielectric layer formed to cover the assembly electrodes; and
and a barrier rib portion stacked on the dielectric layer while forming cells on which the semiconductor light emitting device is mounted along an extension direction of the assembly electrodes. 4. The method of claim 3,
The step (e) may include: vertically moving the fluid ejection module so that the fluid ejection module and the substrate are at a predetermined distance; and
and horizontally moving the fluid ejection module while maintaining the preset interval. 5. The method of claim 4,
A method of manufacturing a display device, characterized in that horizontally moving the fluid ejection module using a direction crossing the extension direction of the assembled electrodes as a main movement path. 4. The method of claim 3,
The step (d) comprises aligning the fluid ejection module such that the nozzle hole faces a partition wall between adjacent cells in an extending direction of the assembled electrodes. According to claim 1,
The first chamber and the second chamber are arranged side by side with a gate interposed therebetween, and in step (c), when the gate is opened, horizontally moving the substrate disposed on the first chamber to the upper part of the second chamber Characterized in, a method of manufacturing a display device. 4. The method of claim 3,
During the steps (b) to (e), a voltage is continuously applied to the assembled electrodes. According to claim 1,
While the steps (a) to (e) are in progress, the inside of the first and second chambers are continuously monitored,
The (d) and (e) steps, characterized in that the further selectively proceeds according to the monitoring content, a method of manufacturing a display device. 10. The method of claim 9,
In the step (e), the moving direction, the moving speed, and the intensity of the fluid injected through the nozzle hole are adjusted according to the monitoring contents, the method of manufacturing a display device.

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