KR20200005234A - Transfer head for micro led - Google Patents

Abstract

The present invention relates to a micro LED transfer head, which adsorbs a micro LED to transfer the same from a growth substrate to a display substrate, and specifically, to a micro LED transfer head, which generates uniform adsorption force on the entire adsorption surface onto which a micro LED is adsorbed, thereby transferring the micro LED to the entire adsorption surface without omission.

Description

Micro LED transfer head {TRANSFER HEAD FOR MICRO LED}

The present invention relates to a micro LED transfer head that absorbs micro LEDs and transfers them from a growth substrate to a display substrate.

Currently, the display market is still the mainstream, while OLED is rapidly becoming the mainstream by replacing LCD. As display companies are participating in the OLED market rush, Micro LED (hereinafter referred to as “micro LED”) display is emerging as another next generation display. Whereas the core materials of LCD and OLED are liquid crystal and organic materials, micro LED display is a display that uses LED chip of 1 ~ 100 micrometer (μm) unit as light emitting material.

When Cree applied for a patent on "Micro-light Emitting Diode Arrays with Improved Light Extraction" in 1999 (Registration No. 0731673), the research and development has been published since the publication of the term micro LED. This is being done. The challenge to apply micro LEDs to displays requires the development of custom microchips based on flexible materials / devices for micro-LED devices, and the accuracy of transfer and display pixel electrodes of micrometer-sized LED chips. There is a need for technology for mounting.

In particular, in connection with the transfer for transferring the micro LED device to the display substrate, as the LED size is reduced to the unit of 1-100 micrometers (μm), it is not possible to use the existing pick & place equipment, There is a need for a transfer head technology that transfers more precisely. In relation to the transfer head technology, several structures as described below have been proposed, but each proposed technology has some disadvantages.

Luxvue of the United States has proposed a method for transferring a micro LED using an electrostatic head (Public Patent Publication No. 2014-0112486, hereinafter referred to as "prior invention 1"). The transfer principle of the present invention 1 is a principle of generating adhesion between the micro LED and the charging by applying a voltage to a head part made of silicon. This method may cause a problem of micro LED damage due to a charging phenomenon due to the voltage applied to the head during the electrostatic induction.

X-Celeprint Inc. of the United States proposed a method of transferring a micro LED on a wafer to a desired substrate by applying a transfer head as an elastic polymer material (Publication Publication No. 2017-0019415, hereinafter referred to as `` Prevention 2 ''). box). This method has no problems with LED damage compared to the electrostatic head method, but it can transfer micro LEDs stably when the transfer force of the elastic transfer head is larger than the adhesive force of the target substrate, and requires an additional process for electrode formation. There are disadvantages. In addition, maintaining the adhesive strength of the elastomeric material is also a very important factor.

The Korean Institute of Optical Technology proposed a method for transferring micro LEDs using a cilia adhesive structure head (registered patent publication No. 1754528, hereinafter referred to as 'prior invention 3'). However, the preceding invention 3 has a disadvantage in that it is difficult to manufacture the adhesive structure of the cilia.

The Korea Institute of Machinery and Materials proposed a method of transferring micro LEDs by coating an adhesive on a roller (registered patent publication No. 1757404, hereinafter referred to as 'prior invention 4'). However, the present invention 4 requires the continuous use of the adhesive, and there is a disadvantage that the micro LED may be damaged when the roller is pressed.

Samsung Display proposed a method of transferring micro LEDs to an array substrate by electrostatic induction by applying a negative voltage to the first and second electrodes of the array substrate while the array substrate is in solution. 2017-0026959, hereinafter referred to as `` First Invention 5 ''). However, the prior invention 5 has a disadvantage in that a separate solution is required in that the micro LED is transferred to the array substrate by soaking in a solution, and then a drying process is required.

LG Electronics has proposed a method of arranging a head holder between a plurality of pickup heads and a substrate and deforming its shape by the movement of the plurality of pickup heads to provide a degree of freedom to the plurality of pickup heads. -2017-0024906, hereinafter referred to as 'prior invention 6'). However, the present invention 6 is a method of transferring a micro LED by applying a bonding material having an adhesive force to the adhesive surface of the plurality of pickup heads, there is a disadvantage that a separate process for applying a bonding material to the pickup head is required.

In order to solve the problems of the preceding inventions, the above-mentioned disadvantages should be improved while adopting the basic principles adopted by the preceding inventions. These disadvantages are derived from the basic principles adopted by the preceding inventions. There are limits to improving the shortcomings. Accordingly, the applicant of the present invention is not only to improve the disadvantages of the prior art, but to propose a new method that has not been considered in the prior inventions at all.

Registered Patent Publication No. 0731673 (Patent Document 2) Publication No. 2014-0112486 Korean Laid-Open Patent Publication No. 2017-0019415 Registered Patent Publication No. 1754528 Registered Patent Publication No. 1757404 Patent Publication No. 10-2017-0026959 Patent Publication No. 10-2017-0024906

Accordingly, an object of the present invention is to provide a micro LED transfer head that can improve the efficiency of micro LED transfer by allowing a uniform adsorption force to occur on the entire adsorption surface on which the micro LED is adsorbed.

Micro LED transfer head according to an aspect of the present invention, a dispersion member having a suction hole in communication with the suction pipe, an upper chamber in communication with the suction hole, and an air passage portion provided in the lower portion of the upper chamber; And

It characterized in that it comprises a; adsorption member provided on the lower portion of the dispersion member.

In addition, the air passage portion is characterized in that composed of a plurality of air passage formed vertically.

In addition, the dispersion member is characterized in that the metal material.

In addition, it characterized in that it comprises a lower chamber formed between the dispersion member and the suction member.

In addition, the adsorption member is characterized in that it is in close contact with the lower surface of the dispersion member.

In addition, the suction member is characterized in that spaced apart from the lower surface of the dispersion member.

In addition, the adsorption member is characterized in that the porous member having an optional pore.

In addition, the adsorption member is characterized in that the porous member having vertical pores.

In addition, the porous member is characterized in that the anodized film.

According to another aspect of the present invention, a micro LED transfer head includes: a dispersion member including a suction hole communicating with a suction pipe and a radiating air passage part radially in air communication with the suction hole; And an adsorption member provided below the dispersion member.

In addition, the dispersion member is characterized in that it comprises a circumferential air passage portion that circumferentially intersects with the radial air passage portion.

In addition, the radiation air passage portion, characterized in that formed with a plurality of protrusions discontinuously provided.

In addition, the radial air passage portion is characterized in that each of the plurality of bands provided in the radial direction are provided in a discontinuous direction in the circumferential direction.

As described above, the micro LED transfer head according to the present invention allows a uniform vacuum pressure to be formed on the entire adsorption member for adsorbing the micro LED, thereby allowing the micro LED to be adsorbed on the adsorption surface of the adsorption member without leaving the micro There is an effect that can improve the transfer efficiency of the micro LED to the LED.

1 is a view showing a micro LED to be transferred in the embodiments of the present invention.
2 is a view of a micro LED structure transferred to and mounted on a display substrate according to embodiments of the present invention.
Figure 3 shows a micro LED transfer head according to a first embodiment of the present invention.
4 is a diagram showing a first modified example of the first embodiment.
Fig. 5 is a diagram showing a second modification of the first embodiment.
6 is a view showing a micro LED transfer head according to a second embodiment of the present invention.
7 is a diagram showing a modification of the second embodiment.

The following merely illustrates the principles of the invention. Therefore, those skilled in the art may implement the principles of the invention and invent various devices included in the concept and scope of the invention, although not explicitly described or illustrated herein. In addition, all conditional terms and embodiments listed herein are in principle clearly intended to be understood only for the purpose of understanding the concept of the invention and are not to be limited to the specifically listed embodiments and states. .

The above objects, features, and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, and thus, it will be possible to easily implement the technical idea of self-invention having ordinary skill in the art. .

Embodiments described herein will be described with reference to cross-sectional and / or perspective views, which are ideal exemplary views of the invention. The thicknesses of the films and regions and the diameters of the holes shown in these figures are exaggerated for the effective explanation of the technical contents. The shape of the exemplary diagram may be modified by manufacturing techniques and / or tolerances. In addition, the number of micro-LEDs shown in the drawings is only a part of the drawings for illustrative purposes. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include changes in forms generated according to manufacturing processes.

In various embodiments of the present disclosure, components that perform the same function will be given the same names and the same reference numbers for convenience, even though the embodiments are different. In addition, the configuration and operation already described in another embodiment will be omitted for convenience.

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

1 is a diagram illustrating a plurality of micro LEDs 100 to be adsorbed by a micro LED adsorbent according to a preferred embodiment of the present invention. The micro LED 100 is fabricated and positioned on the growth substrate 101.

The growth substrate 101 may be made of a conductive substrate or an insulating substrate. For example, the growth substrate 101 may be formed of at least one of sapphire, SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ O ₃ .

The micro LED 100 may include a first semiconductor layer 102, a second semiconductor layer 104, an active layer 103 formed between the first semiconductor layer 102 and the second semiconductor layer 104, and a first contact electrode ( 106 and a second contact electrode 107.

The first semiconductor layer 102, the active layer 103, and the second semiconductor layer 104 may be formed of metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma chemical vapor deposition (CVD). Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), or the like.

The first semiconductor layer 102 may be implemented with, for example, a p-type semiconductor layer. The p-type semiconductor layer is a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x + y≤1), for example, GaN, AlN, AlGaN, InGaN, InN , InAlGaN, AlInN, and the like, and p-type dopants such as Mg, Zn, Ca, Sr, and Ba may be doped. The second semiconductor layer 104 may be formed, for example, including an n-type semiconductor layer. The n-type semiconductor layer is a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x + y≤1), for example, GaN, AlN, AlGaN, InGaN, InNInAlGaN , AlInN, and the like, and n-type dopants such as Si, Ge, Sn, and the like may be doped.

However, the present invention is not limited thereto, and the first semiconductor layer 102 may include an n-type semiconductor layer, and the second semiconductor layer 104 may include a p-type semiconductor layer.

The active layer 103 is a region where electrons and holes are recombined. The active layer 103 may transition to a low energy level as the electrons and holes recombine, and may generate light having a corresponding wavelength. The active layer 103 may include, for example, a semiconductor material having a compositional formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and It may be formed of a quantum well structure or a multi quantum well structure (MQW). In addition, a quantum wire structure or a quantum dot structure may be included.

The first contact electrode 106 may be formed on the first semiconductor layer 102, and the second contact electrode 107 may be formed on the second semiconductor layer 104. The first contact electrode 106 and / or the second contact electrode 107 may comprise one or more layers and may be formed of various conductive materials including metals, conductive oxides and conductive polymers.

The plurality of micro LEDs 100 formed on the growth substrate 101 are cut along the cutting line using a laser or the like, or separately separated by an etching process, and the plurality of micro LEDs 100 are separated by the laser lift-off process. It can be made to be in a state detachable from 101.

In Figure 1 'p' means the pitch interval between the micro LED 100, 's' means the separation distance between the micro LED 100, 'w' means the width of the micro LED (100).

FIG. 2 is a view illustrating a micro LED structure formed by being transferred to a display substrate by a micro LED adsorbent according to a preferred embodiment of the present invention.

The display substrate 300 may include various materials. For example, the display substrate 300 may be made of a transparent glass material mainly containing SiO ₂ . However, the display substrate 300 is not necessarily limited thereto, and may be formed of a transparent plastic material to have solubility. Plastic materials include insulating polyethersulphone (PES), polyacrylate (PAR, polyacrylate), polyetherimide (PEI), polyethylene naphthalate (PEN, polyethyelenen napthalate), polyethylene terephthalate (PET) polyethyeleneterepthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose tri acetate (TAC), cellulose acetate propionate: CAP) may be an organic material selected from the group consisting of.

When the image is a bottom emission type implemented in the direction of the display substrate 300, the display substrate 300 should be formed of a transparent material. However, when the image is a top emission type that is implemented in a direction opposite to the display substrate 300, the display substrate 300 may not necessarily be formed of a transparent material. In this case, the display substrate 300 may be formed of metal.

When the display substrate 300 is formed of metal, the display substrate 300 may include at least one selected from the group consisting of iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), Invar alloy, Inconel alloy, and Kovar alloy. It may include, but is not limited thereto.

The display substrate 300 may include a buffer layer 311. The buffer layer 311 may provide a flat surface and may block foreign matter or moisture from penetrating. For example, the buffer layer 311 may be formed of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide or titanium nitride, or an organic material such as polyimide, polyester, or acryl. And may be formed of a plurality of laminates of the illustrated materials.

The thin film transistor TFT may include an active layer 310, a gate electrode 320, a source electrode 330a, and a drain electrode 330b.

Hereinafter, the thin film transistor TFT will be described as a top gate type in which the active layer 310, the gate electrode 320, the source electrode 330a, and the drain electrode 330b are sequentially formed. However, the present embodiment is not limited thereto, and various types of thin film transistors (TFTs), such as a bottom gate type, may be employed.

The active layer 310 may include a semiconductor material, for example, amorphous silicon or poly crystalline silicon. However, the present embodiment is not limited thereto, and the active layer 310 may contain various materials. In some embodiments, the active layer 310 may contain an organic semiconductor material.

In another alternative embodiment, the active layer 310 may contain an oxide semiconductor material. For example, the active layer 310 may be formed of Group 12, 13, 14 metal elements such as zinc (Zn), indium (In), gallium (Ga), tin (Sn) cadmium (Cd), germanium (Ge), and combinations thereof. Oxides of the selected materials.

A gate insulating layer 313 is formed on the active layer 310. The gate insulating layer 313 insulates the active layer 310 and the gate electrode 320. The gate insulating layer 313 may be formed of a multilayer or a single layer formed of an inorganic material such as silicon oxide and / or silicon nitride.

The gate electrode 320 is formed on the gate insulating layer 313. The gate electrode 320 may be connected to a gate line (not shown) for applying an on / off signal to the thin film transistor TFT.

The gate electrode 320 may be made of a low resistance metal material. The gate electrode 320 is made of aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg) in consideration of adhesion to adjacent layers, surface flatness of the stacked layers, and workability. , Gold (Au), Nickel (Ni), Neodymium (Nd), Iridium (Ir), Chromium (Cr), Lithium (Li), Calcium (Ca), Molybdenum (Mo), Titanium (Ti), Tungsten (W) It may be formed of a single layer or multiple layers of one or more materials of copper (Cu).

An interlayer insulating layer 315 is formed on the gate electrode 320. The interlayer insulating layer 315 insulates the source electrode 330a, the drain electrode 330b, and the gate electrode 320. The interlayer insulating film 315 may be formed of a multilayer or a single layer of an inorganic material. For example, the inorganic material may be a metal oxide or a metal nitride, and specifically, the inorganic material may be silicon oxide (SiO ₂ ), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (Al ₂ O ₃ ), or titanium oxide ( TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), zinc oxide (ZrO ₂ ), and the like.

The source electrode 330a and the drain electrode 330b are formed on the interlayer insulating film 315. The source electrode 330a and the drain electrode 330b include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), and neodymium (Nd). ), Iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), copper (Cu) of one or more materials Can be formed. The source electrode 330a and the drain electrode 330b are electrically connected to the source region and the drain region of the active layer 310, respectively.

The planarization layer 317 is formed on the thin film transistor TFT. The planarization layer 317 is formed to cover the thin film transistor TFT, thereby eliminating a step resulting from the thin film transistor TFT and making the top surface flat. The planarization layer 317 may be formed of a single layer or multiple layers of an organic material. Organic materials include general purpose polymers such as polymethylmethacrylate (PMMA) and polystylene (PS), polymer derivatives having phenolic groups, acrylic polymers, imide polymers, arylether polymers, amide polymers, fluorine polymers, and p-xylene Polymers, vinyl alcohol-based polymers and blends thereof, and the like. In addition, the planarization layer 317 may be formed of a composite laminate of an inorganic insulating film and an organic insulating film.

The first electrode 510 is positioned on the planarization layer 317. The first electrode 510 may be electrically connected to the thin film transistor TFT. In detail, the first electrode 510 may be electrically connected to the drain electrode 330b through a contact hole formed in the planarization layer 317. The first electrode 510 may have various shapes. For example, the first electrode 510 may be patterned in an island shape. The bank layer 400 defining the pixel region may be disposed on the planarization layer 317. The bank layer 400 may include a recess in which the micro LED 100 is to be accommodated. For example, the bank layer 400 may include a first bank layer 410 forming a recess. The height of the first bank layer 410 may be determined by the height and the viewing angle of the micro LED 100. The size (width) of the recess may be determined by the resolution, the pixel density, and the like of the display device. In one embodiment, the height of the micro LED 100 may be greater than the height of the first bank layer 410. The concave portion may have a rectangular cross-sectional shape, but embodiments of the present invention are not limited thereto, and the concave portion may have various cross-sectional shapes such as polygons, rectangles, circles, cones, ellipses, and triangles.

The bank layer 400 may further include a second bank layer 420 on the first bank layer 410. The first bank layer 410 and the second bank layer 420 may have a step difference, and the width of the second bank layer 420 may be smaller than the width of the first bank layer 410. The conductive layer 550 may be disposed on the second bank layer 420. The conductive layer 550 may be disposed in a direction parallel to the data line or the scan line and electrically connected to the second electrode 530. However, the present invention is not limited thereto, and the second bank layer 420 may be omitted, and the conductive layer 550 may be disposed on the first bank layer 410. Alternatively, the second bank layer 420 and the conductive layer 500 may be omitted, and the second electrode 530 may be formed on the entire substrate 301 as a common electrode common to the pixels P. The first bank layer 410 and the second bank layer 420 may include a material that absorbs at least a portion of light, a light reflecting material, or a light scattering material. The first bank layer 410 and the second bank layer 420 may include an insulating material that is translucent or opaque to visible light (eg, light in the wavelength range of 380 nm to 750 nm).

For example, the first bank layer 410 and the second bank layer 420 may include polycarbonate (PC), polyethylene terephthalate (PET), polyethersulfone, polyvinylbutyral, polyphenylene ether, polyamide, poly Thermoplastic resins such as etherimide, norbornene system resins, methacryl resins, cyclic polyolefins, epoxy resins, phenol resins, urethane resins, acrylic resins, vinyl ester resins, imide resins, urethane resins, and urea It may be formed of a thermosetting resin such as resin, melamine resin, or an organic insulating material such as polystyrene, polyacrylonitrile, polycarbonate, but is not limited thereto.

As another example, the first bank layer 410 and the second bank layer 420 may be formed of an inorganic insulating material such as inorganic oxides such as SiOx, SiNx, SiNxOy, AlOx, TiOx, TaOx, ZnOx, and inorganic nitride. It is not limited to this. In one embodiment, the first bank layer 410 and the second bank layer 420 may be formed of an opaque material, such as a black matrix material. Insulating black matrix materials include organic resins, resins or pastes comprising glass paste and black pigments, metal particles such as nickel, aluminum, molybdenum and alloys thereof, metal oxide particles (eg chromium oxide), Or metal nitride particles (eg, chromium nitride) or the like. In a modification, the first bank layer 410 and the second bank layer 420 may be distributed Bragg reflectors (DBRs) having high reflectivity or mirror reflectors formed of metal.

The micro LED 100 is disposed in the recess. The micro LED 100 may be electrically connected to the first electrode 510 in the recess.

The micro LED 100 emits light having a wavelength of red, green, blue, white, and the like, and white light may be realized by using a fluorescent material or combining colors. The micro LED 100 has a size of 1 μm to 100 μm. Each of the micro LEDs 100 is picked up on the growth substrate 101 by an adsorbent according to an exemplary embodiment of the present invention, and transferred to the display substrate 300 by recesses of the display substrate 300. Can be accommodated in

The micro LED 100 includes a p-n diode, a first contact electrode 106 disposed on one side of the p-n diode, and a second contact electrode 107 positioned opposite to the first contact electrode 106. The first contact electrode 106 may be connected to the first electrode 510, and the second contact electrode 107 may be connected to the second electrode 530.

The first electrode 510 may include a reflective film formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof, and a transparent or translucent electrode layer formed on the reflective film. The transparent or translucent electrode layer may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In ₂ O _3, indium oxide), and indium gallium. At least one selected from the group consisting of oxide (IGO; indium gallium oxide) and aluminum zinc oxide (AZO) may be provided.

The passivation layer 520 surrounds the micro LED 100 in the recess. The passivation layer 520 fills the space between the bank layer 400 and the micro LED 100 to cover the recess and the first electrode 510. The passivation layer 520 may be formed of an organic insulating material. For example, the passivation layer 520 may be formed of acrylic, poly (methyl methacrylate) (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy, polyester, and the like, but is not limited thereto. It is not.

The passivation layer 520 is formed above the micro LED 100, for example, at a height not covering the second contact electrode 107, so that the second contact electrode 107 is exposed. A second electrode 530 electrically connected to the exposed second contact electrode 107 of the micro LED 100 may be formed on the passivation layer 520.

The second electrode 530 may be disposed on the micro LED 100 and the passivation layer 520. The second electrode 530 may be formed of a transparent conductive material such as ITO, IZO, ZnO, or In ₂ O ₃ .

First embodiment

3 is a diagram illustrating a micro LED transfer head 1000 according to a first embodiment of the present invention. The micro LED transfer head 1000 according to the first exemplary embodiment of the present invention includes a dispersion member 1100 and an adsorption member 1400 to grow a micro LED (ML) on a first substrate (for example, growth). The substrate 101 is transferred from the substrate 101 to the second substrate (for example, the display substrate 301.) The substrate P shown in FIG. 3 is the first substrate (for example, the growth substrate 101) of FIG. Or a carrier substrate.

As shown in FIG. 3, the dispersion member 1100 includes a suction hole 1100a communicating with the suction pipe 1900, an upper chamber 1100b communicating with the suction hole 1100a, and a lower portion of the upper chamber 1100b. It is provided with an air passage portion 1200 provided in. The dispersion member 1100 may be made of a metal material. The dispersion member 1100 may be made of a metal material to facilitate the fixed support of the adsorption member 1400.

A suction hole 1100a is formed at an upper portion of the dispersion member 1100 to communicate with the suction pipe 1900. The suction hole 1100a may be in communication with the suction pipe 1900 to allow the vacuum supplied from the vacuum pump to be transferred into the dispersion member 1100. An upper chamber 1100b communicating with the suction hole 1100a is provided in the dispersion member 1100. The upper chamber 1100b may transfer a vacuum to the air passage part 1200 provided below. The air passage part 1200 is provided in communication with the upper chamber 1100b at the lower portion of the upper chamber 1100b. The air passage part 1200 includes a plurality of air passages 1300 vertically formed. Therefore, the vacuum of the upper chamber 1100b is transferred to the plurality of air passages 1300. The air passage part 1200 may disperse the received vacuum to the entire upper surface of the adsorption member 1400 provided under the dispersion member 1100. This allows the micro LED transfer head 1000 to generate a uniform adsorption force on the entire adsorption surface for the micro LED (ML).

The air passage part 1200 includes a plurality of air passages 1300 vertically formed to communicate with the upper chamber 1100b at the lower portion of the upper chamber 1100b. As shown in FIG. 3, the air passage 1300 may be formed vertically, and the width of the air passage 1300 may be different for each position where a vacuum passes in the air passage 1300. The width of the inlet 1300a through which the vacuum of the upper chamber 1100b is transferred may be arbitrarily formed. A lower portion of the inlet portion 1300a has a narrow portion 1300b formed to have a width narrower than that of the inlet portion 1300a. Air discharge may be faster flow rate through the narrow portion (1300b). The air discharge having a faster flow rate due to the narrow portion 1300b has an effect of shortening the vacuum pressure forming time when the vacuum pressure for the micro LED ML is formed. The narrow part 1300b has a dispersion part 1300c. Since the air passage part 1200 is provided at the bottom of the dispersion member 1100, the air passage part 1200 may be positioned above the adsorption member 1400 provided below the dispersion member 1100. In addition, since the dispersion units 1300c of the plurality of air passages 1300 are positioned at the bottom of the air passage 1300, the dispersion units 1300c may be positioned above the adsorption member 1400. As a result, the vacuum may be evenly transferred to the upper surface of the adsorption member 1400 while passing through the dispersion unit 1300c. The air is discharged through the narrow portion 1300b and the vacuum degree may be widely distributed to the upper surface of the adsorption member 1400 along the width of the dispersion portion 1300c through the dispersion portion 1300c. At this time, the air passage part 1200 is composed of a plurality of air passages 1300 and the vacuum degree is widely distributed to the upper surface of the adsorption member 1400 along the width of the dispersion portion 1300c of all the air passages 1300 The vacuum may be uniformly transmitted to the entire upper surface of the member 1400. As a result, uniform adsorption force is generated on the entire adsorption surface of the adsorption member 1400 to the micro LEDs (ML), and no vacuum pressure is formed on a portion of the adsorption surface of the adsorption member (1400) so that the micro LEDs (ML) are not adsorbed. It can solve the problem.

On the other hand, the air passage of the air passage portion may be formed vertically with the same width. In the case where the widths of the air passages are vertically formed to be the same, the air passages may be easily formed, and thus the air passages may be easily provided.

The lower portion of the dispersion member 1100 is provided with an adsorption member 1400 is configured with an adsorption surface for adsorbing the micro LED (ML). The adsorption member 1400 may be fixedly supported by the fixing portion 1101 of the dispersion member 1100. Adsorption member 1400 may be composed of a porous member.

The porous member may include a material containing a large number of pores therein, and may be formed in powder, thin film / thick film, and bulk form having a porosity of about 0.2 to 0.95 in a predetermined or disordered pore structure. The pores of the porous member can be classified into micro pores of 2 nm or less in diameter, meso pores of 2 to 50 nm, and macro pores of 50 nm or more, depending on the size thereof. Include. Porous members can be classified into organic, inorganic (ceramic), metal, and hybrid porous materials according to their constituents. In addition, the porous member may be made of one of an organic, inorganic (ceramic), metal, and a hybrid porous material.

The porous member may be powder, coating film or bulk in terms of shape, and in the case of powder, various shapes such as spherical, hollow spherical, fiber, and tubular are possible, and in some cases, powder may be used as it is. It is also possible to manufacture and use a shape.

The porous member may be composed of a porous member having arbitrary pores. When the porous member is composed of a porous member having arbitrary pores, it may be realized by forming arbitrary pores through laser or etching.

As shown in FIG. 3, the adsorption member 1400 may be composed of a porous member having arbitrary pores. The adsorption member 1400, which is a porous member having random pores, may be provided to be in close contact with the bottom surface of the dispersion member 1100. The porous member having random pores has a structure in which air flows in a horizontal direction while a plurality of pores having a predetermined arrangement or disordered pore structure are connected to each other, so that the porous member is in close contact with the bottom surface of the dispersion member 1100. Vacuum pressure can be formed uniformly over the whole. As described above, the adsorption member 1400, which is a porous member having random pores, is provided to be in close contact with the bottom surface of the dispersion member 1100 and receives a vacuum from the air passage part 1200 of the dispersion member 1100. ) Evenly distributed in the horizontal direction can generate a uniform adsorption force on the micro LED (ML) adsorption surface.

4 is a diagram illustrating a first modified example of the micro LED transfer head 1000 according to the first embodiment. The first modified example is different from the first embodiment in that the adsorption member 1400 is formed of a porous member having arbitrary pores and is spaced apart from the lower surface of the dispersion member 1100 and provided with a lower chamber.

As shown in FIG. 4, the micro LED transfer head 1000 of the first modified example is provided with an adsorption member 1400 spaced apart from the bottom surface of the dispersion member 1100. The lower chamber 1500 is provided between the dispersion member 1100 and the suction member 1400. The air passage part 1200 is provided at the lower end of the dispersion member 1100. Accordingly, the lower chamber 1500 may be provided between the dispersion member 1100 and the adsorption member 1400 and at the bottom of the air passage part 1200 of the dispersion member 1100. The lower chamber 1500 is provided in communication with the air passage 1200. As a result, the vacuum supplied from the vacuum pump may be transferred to the lower chamber 1500 via the upper chamber 1100b and the air passage part 1200. The lower chamber 1500 in communication with the air passage part 1200 may apply the received vacuum to the adsorption member 1400. Since the adsorption member 1400 is provided to be spaced apart from the dispersion member 1100, the air flow inside the adsorption member 1400 may be smoother than that of the structure in which the adsorption member 1400 is in close contact with the dispersion member 1100. The vacuum is well transmitted to the entirety of the member 1400, so that the adsorption force can be evenly generated.

5 is a diagram illustrating a second modified example of the micro LED transfer head 1000 according to the first embodiment. The second modified example is different from the first embodiment in that the porous member having arbitrary pores is provided with an adsorption member 1400 ', which is an anodized film, spaced apart from the lower surface of the dispersion member 1100, and the lower chamber 1500 is provided. There is a difference.

 As shown in FIG. 5, the micro LED transfer head 1000 according to the second modified example is provided with an adsorption member 1400 ′ formed of an anodization film spaced apart from the bottom surface of the dispersion member 1100.

The pores of the anodic oxide film are formed in a predetermined arrangement. The anodic oxide film refers to a film formed by anodizing a base metal, and the pore refers to a hole formed in the process of forming an anodized film by anodizing a metal. For example, in the case of aluminum (Al) or an aluminum alloy, which is a base metal, anodizing the base material forms an anodized film made of anodized aluminum (Al ₂ O ₃ ) on the surface of the base material. The anodic oxide film formed as described above is divided into a barrier layer having no pores formed therein and a porous layer having pores formed therein. The barrier layer is located on top of the base material, and the porous layer is located on top of the barrier layer. As such, when the base material is removed from the base material having the barrier layer and the porous layer formed on the surface, only the anodized film made of aluminum anodized (Al ₂ O ₃ ) material remains.

The anodic oxide film has pores having a regular arrangement while having a uniform diameter and a vertical shape. Therefore, when the barrier layer is removed, the pores have a vertically penetrating structure up and down, thereby making it easy to form a vacuum pressure in the vertical direction.

The inside of the anodic oxide film can form an air flow path in a vertical form by vertical pores. The inner width of the pores has a size of several nm to several hundred nm. For example, when the size of the micro LED to be vacuum adsorbed is 30 μm × 30 μm and the internal width of the pores is several nm, the micro LED (ML) may be vacuum adsorbed using approximately tens of millions of pores. On the other hand, when the size of the micro LED to be vacuum adsorbed is 30μm x 30μm and the inside width of the pores 1303 is several hundred nm, it is possible to vacuum adsorb the micro LED (ML) using approximately tens of thousands of pores. do. In the case of the micro LED (ML), basically, the first semiconductor layer 102, the second semiconductor layer 104, the active layer 103 formed between the first semiconductor layer 102 and the second semiconductor layer 104, Since only the first contact electrode 106 and the second contact electrode 107 are relatively light, vacuum adsorption is possible using tens of thousands to tens of millions of pores of the anodization film.

The adsorption member 1400 'composed of the anodic oxide film forms a vertical air flow path so that only the air flows in the vertical direction inside the adsorption member 1400'. In other words, there is no horizontal air flow inside the adsorption member 1400 '. If only the air flow in the vertical direction in the adsorption member 1400, as shown in the first embodiment of Figure 3 when the adsorption member 1400 'is provided in a structure that is in close contact with the lower surface of the dispersion member 1100 (air passage part ( The vacuum passing through 1200 is transmitted only to the vertical air flow path of the suction member 1400 ′ in close contact with the dispersion 1300c of the air passage part 1200. In other words, the air passage 1300 of the air passage portion 1200 is not formed in the structure in which the adsorption member 1400 'composed of the anodized film having only the vertical air flow is in close contact with the bottom surface of the dispersion member 1100. There is a vertical air flow path of the adsorption member 1400 'in close contact with the non-position. The vacuum is not transmitted to the air flow path of the suction member 1400 'at this position. Here, the air flow path may be pores of the anodization film. In the structure in which the adsorption member 1400 'composed of the anodic oxide film is in close contact with the bottom surface of the dispersion member 1100, the vacuum is not dispersed throughout the adsorption member 1400', so that uniform vacuum pressure is formed throughout the adsorption member 1400 '. It may not be done. This may cause the uniform adsorption force not to occur on the adsorption surface of the adsorption member 1400 '. Therefore, the second modified example is provided with an adsorption member 1400 'composed of an anodized film spaced apart from the lower surface of the dispersion member 1100, and the adsorption member 1400' through the air passage portion 1200 and the lower chamber 1500. The vacuum can be uniformly delivered to the inside.

The vacuum supplied from the vacuum pump may be uniformly distributed on the upper portion of the suction member 1400 ′ primarily through the air passage 1200 through the upper chamber 1100b. The upper portion of the adsorption member 1400 'is a position formed by being spaced apart from the lower surface of the dispersion member 1100 by the adsorption member 1400', and may be a position where the lower chamber 1500 is provided. The vacuum uniformly uniformly distributed through the air passage part 1200 may increase the flow velocity through the narrow portion 1300b of the air passage part 1200. The vacuum transferred to the lower chamber 1500 at a high flow rate may shorten the vacuum pressure forming time of the suction member 1400 '. The vacuum uniformly uniformly distributed through the air passage part 1200 may be secondary uniformly dispersed to the adsorption member 1400 'through the lower chamber 1500. Since the adsorption member 1400 'is provided to be spaced apart from the bottom surface of the dispersion member 1100, the adsorption member 1400' is in close contact with the bottom surface of the dispersion member 1100. Since the upper surface is not shielded, the lower chamber 1500 may uniformly transmit the vacuum through all the air flow paths of the suction member 1400 ′. As a result, uniform vacuum pressure can be formed on the entire adsorption surface of the adsorption member 1400 ', thereby eliminating the problem of the micro LED (ML) not being adsorbed and improving the micro LED (ML) transfer efficiency. do.

Meanwhile, the adsorption member 1400 ′ may be a porous member having vertical pores. The porous member having vertical pores may be implemented through laser or etching. The porous member having vertical pores penetrates up and down of the porous member by vertical pores to form an air flow path. Therefore, the adsorption member 1400 ', which is composed of a porous member having vertical pores, such as an anodization film, is provided on the lower surface of the dispersion member 1100 to be primarily uniformly distributed through the air passage part 1200 and the lower portion. Secondary uniform dispersion through the chamber 1500 may generate a uniform adsorption force on the entire adsorption surface.

Second embodiment

Hereinafter, the micro LED transfer head 1000 according to the second embodiment will be described with reference to FIG. 6. However, the second embodiment to be described below will be described based on the characteristic elements compared to the first embodiment, and descriptions of the same or similar elements as the first embodiment will be omitted.

6 illustrates a micro LED transfer head 1000 according to a second embodiment of the present invention. FIG. 6 (a) is a view showing the bottom surface of the dispersion member 1100 constituting the micro LED transfer head 1000 of the second embodiment. FIG. 6 (b) shows an adsorption member 1400 provided on the lower surface of the dispersion member 1100 'cut along the line AA ′ of FIG. 6 (a) to form the micro LED transfer head 1000 of the second embodiment. Figure 6 (c) is a micro LED of the second embodiment is provided with the adsorption member 1400 is provided on the lower surface of the dispersion member 1100 'cut along the line B-B' of Figure 6 (a). Fig. 1 shows the configuration of the transfer head 1000. Figs.

The micro LED transfer head 1000 according to the second embodiment does not include an air passage portion 1200 including a plurality of vertical air passages 1300 in the dispersion member 1100 described in the first embodiment. Characterized in that the passage portion 1600 and the circumferential air passage portion 1700 is provided.

As shown in FIG. 6, the micro LED transfer head 1000 according to the second exemplary embodiment includes a suction hole 1100a communicating with the suction pipe 1900 and radial air communicating radially with the suction hole 1100a. A dispersion member 1100 'having a passage portion 1600, and a suction member 1400 provided at a lower portion of the dispersion member 1100'.

As shown in FIG. 6 (a), the dispersion member 1100 ′ is provided with a suction hole 1100 a in communication with the suction pipe 1900. In FIG. 6 (a), the suction member is formed at the center of the circular cross section based on the dispersion member 1100 ′ having the circular cross section. Here, the center of the circular cross section may mean a position moved inward by the radius of the circular cross section. In FIG. 6A, although the suction hole 1100a of the dispersion member 1100 'is formed at the center, the suction hole 1100a is not limited thereto. In addition, when the dispersion member 1100 ′ has a different cross-sectional shape such as a square cross section instead of a circular cross section, the meaning of the center where the suction hole 1100 a is formed may vary.

An outer portion of the dispersion member 1100 ′ is provided with a fixing part 1101 for supporting and fixing the adsorption member 1400. Referring to FIG. 6A, the fixing part 1101 is formed continuously around the dispersion member 1100 ′ surrounding a plurality of discontinuously provided protrusions 1102 of the dispersion member 1100 which will be described later. The fixing part 1101 may be formed to a thickness thicker than the protrusion 1102 to fix and support the adsorption member 1400.

The dispersion member 1100 ′ is provided with a radial air passage 1600 that is radially in air communication with the suction hole 1100 a based on the suction hole 1100 a formed at the center thereof. The radiation air passage 1600 may be formed by providing a plurality of protrusions 1102 discontinuously. The radial air passage portion 1600 which is radially in air communication with the suction hole 1100a is formed to cross the suction hole 1100a and has a plurality of continuous protrusions provided in a radial direction in a horizontal direction, thereby providing a plurality of protrusions 1102. Can be formed discontinuously. The plurality of protrusions 1102 that are provided discontinuously may have a shape in which each of the plurality of bands provided in the radial direction is provided discontinuously in the circumferential direction. The radiation air passage 1600 has an air passage 1800 formed on the same circumference of the protrusions continuously provided in the circumferential direction, and the air passage 1800 is formed to correspond to each of the plurality of protrusions 1102. It can be formed by being provided radially. As shown in FIG. 6 (a), the radiation air passage 1600 may be formed to correspond to each other in each of the plurality of protrusions 1102 such that the air passage 1800 may be radially in air communication with the suction hole 1100a. In some embodiments, the air passage 1800 may be formed to correspond to each of the plurality of protrusions 1102 to be in air communication with the suction hole 1100a. When the air passage 1800 is formed to correspond to each of the plurality of protrusions 1102, the air passage 1800 is not radially provided, and thus the air passage 1800 may be provided as the air passage portion in the dispersion member 1100 ′. Here, the air passage 1800 of the second embodiment uses the same name as the vertical air passage 1300 of the first embodiment, but unlike the first embodiment, the dispersion member 1100 ′ radially moves to the suction hole 1100a. It may be an air passage 1800 to allow air communication.

The dispersion member 1100 ′ having the radiation air passage portion 1600 may include a circumferential air passage portion 1700 that circumferentially intersects the radiation air passage portion 1600. The circumferential air passage 1700 may be formed due to a radial distance between the protrusions 1102 while being provided with a plurality of discontinuous protrusions 1102 provided in the dispersion member 1100 ′. Since the plurality of protrusions 1102 are discontinuously provided in the dispersion member 1100 ′ and form the radial air passage portions 1600, the circumferential air passage portions formed by the radial distances between the protrusions 1102 ( 1700 may be formed while circumferentially intersecting the radiating air passage 1600.

The dispersion member 1100 ′ includes a radiation air passage portion 1600 and a circumferential air passage portion 1700 circumferentially intersecting with the radiation air passage portion 1600, whereby the suction hole communicates with the suction pipe 1900. Vacuum supplied to the (1100a) can be uniformly dispersed throughout the upper surface of the adsorption member (1400). As shown in FIGS. 6 (b) and 6 (c), the adsorption member 1400 is provided under the dispersion member 1100 ′. As shown in Figure 6 (c), the adsorption member 1400 is provided in close contact with the lower portion of the dispersion member 1100 '. Since the dispersion member 1100 ′ is formed with a plurality of protrusions 1102, the upper surface of the adsorption member 1400 corresponding to the plurality of protrusions 1102 of the dispersion member 1100 is a protrusion 1102 of the dispersion member 1100 ′. ) May be in close contact with the bottom surface. Referring to FIG. 6B again, a distance equal to the thickness of the protrusion 1102 of the dispersion member 1100 may be formed between the radiation air passage 1600 and the suction member 1400 of the dispersion member 1100. Can be. The vacuum supplied through the suction hole 1100a may be radially distributed through the radial air passage 1600 in air communication with the suction hole 1100a. In addition, due to the circumferential air passage 1700 that intersects the radiating air passage 1600, the vacuum may be dispersed throughout the upper surface of the adsorption member 1400. As a result, a uniform vacuum pressure is formed on the entire adsorption surface, and the adsorption member 1400 is adsorbed without the micro LED (ML) being absent on the adsorption surface, thereby improving the transfer efficiency of the micro LED (ML).

As shown in FIG. 6C, the protrusion 1102 of the dispersion member 1100 ′ may function to prevent deformation of the adsorption member 1400. When the adsorption member 1400 is composed of a porous member, when the thickness thereof is thinned, the flow resistance may be lowered, so that the vacuum pressure may be easily formed to adsorb the micro LED (ML). However, when the thickness of the adsorption member 1400 is thin, the adsorption member 1400 may be deformed such as sag by vacuum pressure. Accordingly, the present invention supports the adsorption member 1400 so that the adsorption member 1400 is not deformed while the lower surface of the protrusion 1102 contacts the upper surface of the adsorption member 1400 through the protrusion 1102 of the dispersion member 1100. To prevent deflection deformation. Thus, the adsorption member 1400 may be provided with a thin thickness, and the flow resistance may be lowered, thereby obtaining an effect of facilitating the vacuum pressure formation.

7 is a diagram illustrating a modified example of the micro LED transfer head 1000 according to the second embodiment. The modified example is different from the second embodiment in that the dispersion member 1100 includes a plurality of suction holes 1100a communicating with the suction pipe 1900.

As shown in FIG. 7, the micro LED transfer head 1000 of the modified example includes a plurality of suction holes 1100a in communication with the suction pipe 1900 in the dispersion member 1100 '. Although the plurality of suction holes 1100a are not limited thereto, the suction holes 1100a may be provided at positions suitable for supplying a uniform vacuum to the entire upper surface of the suction member 1400.

FIG. 7A is a view showing the dispersing member 1100 'constituting the micro LED transfer head 1000 according to a modified example from below. FIG. 7B is a view showing an embodiment in which the adsorption member 1400 is provided under the dispersing member 1100 'cut along the line AA ′ of FIG. 7A to form a micro LED transfer head 1000 according to a modification. Figure shown.

 As shown in FIG. 7A, the dispersion member 1100 ′ includes a plurality of suction holes 1100a. The position at which the suction hole 1100a is illustrated in FIG. 7A is one example for supplying a uniform vacuum to the entire upper surface of the suction member 1400. It will be described that the plurality of suction holes 1100a are configured as the suction holes 2100 outside the central suction hole 2000 in the dispersion member 1100 'constituting the micro LED transfer head 1000 according to the modification.

As shown in FIG. 7A, a central suction hole 2000 is formed at a position moved inward by a radius of a circular cross section at the center of the dispersion member 1100 ′ having a circular cross section. The outer suction hole 2100 is formed at one end of the radial air passage 1600 in radial air communication with the central suction hole 2000. For this reason, the outer suction hole 2100 may have a shape opposite to the central suction hole 2000.

Dispersion member 1100 is provided with a central suction hole (2000) and the outer suction hole (2100) and in air communication with the radiating air passage portion 1600, and the circumferential air passage portion crossing the radiating air passage portion 1600 ( Through 1700, the vacuum may be transferred to the entire upper portion of the adsorption member 1400. As shown in 7 (b), due to the radiation air passage 1600, the adsorption member 1400 is provided to be spaced apart from the dispersion member 1100 'by the thickness of the protrusion 1102 of the dispersion member 1100'. The vacuum supplied through the central suction hole 2000 and the outer suction hole 2100 may be uniformly transmitted to the entire upper portion of the suction member 1400 through the radial air passage part 1600 and the circumferential air passage part 1700. Can be. In addition, because of the separation distance due to the protrusion 1102 of the dispersion member 1100 ′, a smooth air flow can be made in the horizontal direction on the upper portion of the adsorption member 1400, so that a more efficient vacuum transfer to the entire adsorption member 1400 is achieved. Can be done.

As described above, although described with reference to preferred embodiments of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below. Or it may be modified.

1000: micro LED transfer head
1100, 1100 ': dispersion member 1101: fixing part
1102: protrusion 1100a: suction hole
1100b: upper chamber 1200: air passage portion
1300: air passage 1300a: inlet
1300b: narrow part 1300c: dispersion part
1400, 1400 ': adsorption member 1500: lower chamber
1600: radial air passage portion 1700: circumferential air passage portion
1800: air passage in the radiating air passage 1900: suction pipe
2000: central suction hole 2100: outer suction hole
ML: Micro LED P: Substrate

Claims (13)

A dispersion member including a suction hole communicating with a suction pipe, an upper chamber communicating with the suction hole, and an air passage part provided below the upper chamber; And
Micro LED transfer head comprising a; adsorption member provided in the lower portion of the dispersion member.
The method of claim 1,
And the air passage portion comprises a plurality of air passages formed vertically.
The method of claim 1,
The dispersion member is a micro LED transfer head, characterized in that the metal material.
The method of claim 1,
And a lower chamber formed between the dispersion member and the suction member.
The method of claim 1,
The adsorption member is in close contact with the lower surface of the dispersion member micro LED transfer head.
The method of claim 1,
The suction member is micro LED transfer head, characterized in that spaced apart from the lower surface of the dispersion member.
The method of claim 1,
The adsorption member is a micro LED transfer head, characterized in that the porous member having an optional pore.
The method of claim 1,
The adsorption member is a micro LED transfer head, characterized in that the porous member having vertical pores.
The method of claim 8,
The porous member is a micro LED transfer head, characterized in that the anodization film.
A dispersion member including a suction hole communicating with a suction pipe, and a radial air passage part radially in air communication with the suction hole; And
Micro LED transfer head comprising a; adsorption member provided in the lower portion of the dispersion member.
The method of claim 10,
The dispersion member,
And a circumferential air passage portion that circumferentially intersects with the radiating air passage portion.
The method of claim 10,
The radiation air passage portion,
Micro LED transfer head, characterized in that formed with a plurality of protrusions discontinuously.
The method of claim 10,
The radiation air passage portion,
Micro LED transfer head, characterized in that formed in a plurality of bands provided in the radial direction discontinuously provided in the circumferential direction.

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