Rework device and rework method for ultra-small LED chips using transfer method

Abstract

The micro-miniature LED chip rework device using the transfer method according to the present invention is an micro-miniature LED chip rework device for removing defective micro-miniature LED chips that are misaligned or have defective performance among a plurality of micro-miniature LED chips transferred by a first adhesive layer on a substrate, and is characterized by including a detachment pressure head that is stick-shaped and has a second adhesive layer having a stronger adhesive strength than the first adhesive layer on its bottom surface, and pressurizes the upper surface of the defective micro-miniature LED chip to transfer and remove the defective micro-miniature LED chip attached on the first adhesive layer to the second adhesive layer, and a driving unit that moves the detachment pressure head in X, Y, and Z axis directions on the substrate.

Description

[Technical Field]

[0001] The present invention relates to a rework device and method for micro LED chips, and more particularly, to a rework device and method for micro LED chips using a transfer method, which not only allows for fast and accurate removal of the defective micro LED chip from a substrate when misalignment occurs due to slight vibration or impact during a chip bonding process, but also allows for fast and accurate attachment of a micro LED chip for rework to the substrate at the location where the defective micro LED chip was removed, thereby shortening takt time and significantly improving process efficiency and accuracy. [Background technology]

[0002] Recently, ultra-small LEDs (light emitting diodes) measuring tens to hundreds of microns in size have been increasingly used as light sources for various displays due to their many advantages, such as compact size, light weight, and low power consumption.

[0003] These ultra-compact LEDs can be divided into mini LEDs with chip sizes of 100 to 300 μm and micro LEDs with chip sizes of 5 to 100 μm.

[0004] Mini LEDs have a relatively larger chip size than micro LEDs, and are primarily used in backlight units that display images on LCD displays by emitting light from the rear, rather than as direct light-emitting pixels in LED displays.

[0005] Meanwhile, micro LEDs are expected to be in the spotlight as the next generation of ultra-small LED chip elements as they can be applied to optical application fields that require ultra-small size (integration), low power consumption, and light weight. As the chip size is smaller than that of mini LEDs and each LED chip can be used as an individual pixel or light source, active research is being conducted into using these micro LEDs as pixels for LED displays that display images by directly emitting light by arranging them horizontally or vertically.

[0006] [Figure 1] A plan view showing the configuration of a typical ultra-compact LED (mini LED) array.

[0007] Referring to FIG. 1, when such mini LEDs are typically applied to a backlight unit, one or more series-connected mini LED chip groups are arranged horizontally / vertically to form a mini LED array.

[0008] Conventional mini LEDs are provided as a mini LED array 100 in which a plurality of mini LED chips (121, 122, 123, 124) having a chip size of 100 to 200 μm are connected in series on a substrate 110 and arranged horizontally / vertically as a mini LED chip group 120.

[0009] In the case of mini LEDs, this is generally done by forming the circuits for each chip on a wafer and then separating it into multiple individual chips.

[0010] The mini LED chips separated in this way are transferred or mounted on a substrate through multiple transfer processes in the packaging and module process.

[0011] The conventional LED chip transfer process is generally performed by transferring the LED chip to a transfer tape or substrate, or by directly mounting the LED chip on a circuit board (e.g., a rigid PCB or a flexible PCB). A typical example of the conventional LED chip transfer process is a pick and place type transfer device.

[0012] As an example of such a pick and place type transfer device, Korean Patent Publication No. 1879029 (registered on July 10, 2018) discloses a chip transfer device and transfer method that transfers each LED chip to a substrate by picking up each LED chip one by one and placing it on a substrate.

[0013] Meanwhile, Korean Patent Publication No. 2130124 (registered on June 29, 2020) describes a mounting device that has a head drive unit and a mounting head attached to the head drive unit and mounts components attached to a sheet on a substrate, and the mounting head includes a head body, a plunger that is disposed on the head body and moves up and down, and an ejector pin that is fixed to the head body and penetrates the plunger in the reciprocating direction of the plunger. and a solenoid fixed to the head body for moving the plunger, the plunger being a movable iron core, having a shaft portion, a flange provided on the tip side of the shaft portion, a tip portion tapered from the shaft portion to the tip, and a nipple portion that is narrower than the narrowest diameter portion of the tip portion that is tapered from the shaft portion and is located at the top of the tip portion, the shaft portion and the flange being disposed inside the head body, and the tip portion and the nipple portion protruding from the head body, the plunger protruding most from the head body when the solenoid is off, and when the solenoid is on, the plunger moves toward the head drive unit, and the ejector pin protrudes relatively from the plunger.

[0014] In addition, Korean Patent Publication No. 1937071 (registered on January 3, 2019) describes a device for transferring semiconductor devices, which includes a first frame for holding a wafer tape having a first side and a second side (a plurality of semiconductor device dies are arranged on the first side of the wafer tape); a second frame including a first clamping member and a second clamping member, the second frame clamping an output substrate having circuit traces between the first clamping member and the second clamping member, the second frame holding the output substrate such that the circuit traces are positioned toward the plurality of semiconductor device dies on the wafer tape; a needle disposed adjacent to a second side of the wafer tape, the needle having a length extending in a direction toward the wafer tape; a needle actuator coupled to the needle, the needle actuator moving the needle to a die transfer position where the needle presses against a second side of the wafer tape to press one of the plurality of semiconductor device dies into contact with a circuit trace on the output substrate; The device further includes a laser positioned toward a portion of the output substrate corresponding to the transfer position where the semiconductor device die contacts the circuit traces to apply energy to the circuit traces to attach the semiconductor device die to the circuit traces, the laser being positioned within the device so that energy from the laser is transmitted directly onto the output substrate during the transfer operation.As another example, an individual transfer type mounting device using ejector pins (needles) is disclosed.

[0015] In addition, Korean Patent Publication No. 2020-0109493 (published on September 23, 2020) describes a transfer device for transferring a semiconductor chip, comprising: a stage on which a first substrate having the semiconductor chip mounted on one surface is placed; a work table on which a second substrate onto which the semiconductor chip is transferred is placed; and a push pin module configured to press a portion of the other surface of the first substrate corresponding to the semiconductor chip to transfer the semiconductor chip to the second substrate while the first substrate and the second substrate are disposed opposite each other, the push pin module includes a push pin unit including a push pin for pressing the other surface of the first base material; The device includes a load adjustment unit that adjusts the load applied to the push pin when the semiconductor chip is transferred to the second substrate, and the load adjustment unit includes a VCM (voice coil motor) stator and a VCM mover, and when a force greater than a preset load is applied to the push pin when the semiconductor chip is transferred to the second substrate, the VCM mover moves in the direction opposite to the moving direction of the push pin.As another example, an individual transfer type mounting device using an ejector pin (needle) has been disclosed.

[0016] However, as mentioned above, while the conventional technologies of pick and place, which transfers or mounts individual LED chips one by one, or individual transfer methods using ejector pins may be applicable to processes for mini LED chips of several hundred microns or more, in the case of micro LED chip arrays, whose chip size and chip spacing are 5 to 100 microns and are becoming smaller every day, the miniaturization of the chip size and chip spacing makes it difficult to use the pick and place method or individual transfer method.

[0017] Meanwhile, as the screen size of micro LED displays continues to grow larger, considering future trends, it is necessary to transfer a large number of fine micro LED chips one by one quickly and accurately onto large-area displays. However, the conventional individual transfer method using pick and place or ejector pins has practical limitations in terms of transferring or mounting each chip accurately onto a substrate without misalignment.

[0018] In addition, even if micro LED chips are transferred or mounted one by one onto a substrate using conventional pick and place or individual transfer technology using ejector pins, there is a risk of misalignment of some ultra-small LED chips due to slight vibrations or shocks that occur during the transfer process, as shown in Figure 2.

[0019] However, in the past, this could not be resolved on-site, and the substrate had to be judged as defective before being shipped out and then collected, or a separate rework process had to be carried out to deal with the defect, which led to many problems such as an increase in tact time as well as a decrease in process efficiency and production volume. Summary of the Invention [Problem to be solved by the invention]

[0020] Therefore, the present invention has been invented to solve the above problems, and aims to provide an ultra-small LED chip rework device using a transfer method that can quickly and accurately remove a defective micro LED chip from a substrate when misalignment occurs due to slight vibration or impact during the chip bonding process, and also quickly and accurately attach a micro LED chip for rework to the substrate using the transfer method again at the location from which the defective micro LED chip was removed, thereby shortening takt time and significantly improving process efficiency and accuracy. [Means for solving the problem]

[0021] In order to achieve the above object, according to one embodiment, the micro-miniature LED chip rework device using the transfer method of the present invention is an micro-miniature LED chip rework device that removes defective micro-miniature LED chips that are misaligned or have defective performance from among a plurality of micro-miniature LED chips transferred onto a substrate by a first adhesive layer, the micro-miniature LED chip rework device comprising: a detachment pressure head that is stick-shaped and has a second adhesive layer on the bottom of the stick-shaped chip that is stronger in adhesive strength than the first adhesive layer, and that applies pressure to an upper surface of the defective micro-miniature LED chip that is attached to the first adhesive layer to transfer the defective micro-miniature LED chip to the second adhesive layer and remove the defective micro-miniature LED chip; The detachment pressure head further includes a driving unit that moves the detachment pressure head in the X, Y, and Z axis directions on the substrate.

[0022] According to one embodiment, the drive unit moves the LED chip in the X, Y, and Z-axis directions on the substrate to form the stick shape, a third adhesive layer having a weaker adhesive strength than the first adhesive layer is provided on a bottom surface of the stick shape, and a replacement normal microminiature LED chip for rework is attached to the bottom surface of the third adhesive layer, and the LED chip further includes an attach pressure head that applies pressure to the first adhesive layer of the defective microminiature LED chip removed by the detach pressure head to transfer the replacement normal microminiature LED chip attached to the third adhesive layer to the first adhesive layer, thereby recovering the defective microminiature LED chip.

[0023] According to one embodiment, the driving unit includes a linear transport unit that moves the detachment pressure head in X and Y axis directions; The apparatus also includes an up-down drive unit that raises and lowers the detachment pressure head in the Z-axis direction.

[0024] According to one embodiment, the second adhesive layer is formed on one side of a first transfer film that is transported reel-to-reel in a horizontal direction, and the detachment pressure head selectively presses and presses the other side of the first transfer film in a vertical direction.

[0025] According to one embodiment, the third adhesive layer is formed on one side of a second transfer film that is transported reel-to-reel in a horizontal direction, and an attachment pressure head selectively presses and applies pressure to the other side of the second transfer film in a vertical direction.

[0026] Meanwhile, the method for reworking ultra-small LED chips using a transfer method according to the present invention includes the steps of: (a) moving and positioning a detachment pressure head, which is provided in a stick shape above a defective ultra-small LED chip to be reworked and which has been transferred to a first adhesive layer on a substrate, and which has a second adhesive layer on the bottom surface of the stick, the second adhesive layer having stronger adhesive strength than the first adhesive layer; (b) the detachment pressure head is lowered to press and apply pressure to the first adhesive layer while the second adhesive layer is in contact with the defective micro-miniature LED chip; (c) As the detachment pressure head rises, the defective ultra-small LED chip transferred to the second adhesive layer having stronger adhesive strength than the first adhesive layer is separated from the first adhesive layer and rises together with the detachment pressure head while attached to the second adhesive layer.

[0027] According to one embodiment, after the step (c), (d) a step of providing the third adhesive layer having a weaker adhesive strength than the first adhesive layer on the bottom surface of the stick-shaped member, and positioning an attachment pressure head provided with a normal replacement microminiature LED chip attached to the bottom surface of the third adhesive layer above the first adhesive layer from which the defective microminiature LED chip has been removed, is also included. (e) a step of transferring the normal replacement microminiature LED chip attached to the third adhesive layer to the first adhesive layer by lowering the attachment pressure head and applying pressure to the first adhesive layer from which the defective microminiature LED chip has been removed, thereby recovering the normal replacement microminiature LED chip attached to the third adhesive layer; (f) the attachment pressure head from which the replacement normal microminiature LED chip has been separated rises again to its original position. [Effects of the Invention]

[0028] The present invention described above can transfer the micro LED chip to the substrate quickly and accurately by using the difference in adhesive strength between the adhesive layer applied to the bottom surface of the transfer film and the top surface of the substrate, thereby reducing the takt time of the ultra-small micro LED transfer process and significantly improving the process efficiency.

[0029] In addition, even if misalignment occurs due to slight vibration or impact during the transfer process, the micro LED chip with the misalignment can be repaired immediately on-site, which has the effect of significantly improving efficiency and productivity compared to the conventional transfer method using pick and place or ejector pins. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a plan view showing the configuration of a micro LED chip array for a general backlight unit.

[0031] [Figure 2] FIG. 1 is an enlarged plan view showing an ultra-small LED chip array transferred onto a conventional substrate.

[0032] [Figure 3a] 1 is a diagram showing the operation of the micro-miniature LED chip rework device using the transfer method according to the present invention, in which the detachment pressure head is positioned above the defective micro-miniature LED chip that is the target of the rework operation. [Figure 3b] 1 is a diagram illustrating the operation of the micro-miniature LED chip rework device using the transfer method according to the present invention, showing the state in which the detachment pressure head descends to pressurize the defective micro-miniature LED chip. [Figure 3c] 1 is a diagram showing the operation of the micro-miniature LED chip rework device using the transfer method according to the present invention, showing the state in which the detachment pressure head is rising after removing the defective micro-miniature LED chip by transfer. [Figure 3d] 1 is a diagram showing the operation of the micro-miniature LED chip rework device using the transfer method according to the present invention, in which the attachment pressure head is positioned above the removed defective micro-miniature LED chip. [Figure 3e] 1 is a diagram showing the operation of the micro-miniature LED chip rework device using the transfer method of the present invention, in which the attachment pressure head descends to transfer and attach a normal micro-miniature LED chip for rework onto the substrate. [Figure 3f] 1 is a diagram showing the operation of the micro-miniature LED chip rework device using the transfer method according to the present invention, in which the attachment pressure head is raised again after a normal micro-miniature LED chip has been attached to a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0033] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. It should be understood that, in this specification, the terms "comprise," "have," "use," and the like specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described herein, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0034] Unless otherwise defined herein, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0035] Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0036] Hereinafter, the rework device for micro LED chips using a transfer method according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0037] Figures 3a to 3f are operating state diagrams of the micro-LED chip rework device using the transfer method of the present invention, where Figure 3a shows the state in which the detachment pressure head is positioned above the defective micro-LED chip to be reworked, Figure 3b shows the state in which the detachment pressure head is lowered to pressurize the defective micro-LED chip, Figure 3c shows the state in which the detachment pressure head is raised after removing the defective micro-LED chip by transfer, Figure 3d shows the state in which the attachment pressure head is positioned above the removed defective micro-LED chip, Figure 3e shows the state in which the attachment pressure head is lowered to attach a normal micro-LED chip for rework onto the substrate by transfer, and Figure 3f shows the state in which the attachment pressure head is raised again after the normal micro-LED chip has been attached to the substrate.

[0038] The micro LED chip rework device 300 using the transfer method of the present invention is a device for removing or replacing defective micro LED chips FC that are misaligned or have performance defects among multiple micro LED chips NC transferred onto a substrate S by a first adhesive layer AL1.

[0039] The micro LED chips NC transferred onto the substrate S may be a flexible micro LED array in which multiple micro LED chips NC each measuring 20 μm x 40 μm are repeatedly arranged at regular intervals (e.g., 2 μm) on the flexible substrate S using a transfer method (see Figure 2).

[0040] In order to selectively rework (remove the defective LED chip FC and replace it with a normal LED chip RC) the defective ultra-small LED chip FC from among the plurality of ultra-small LED chips NC, the rework device 300 of the present invention is stick-shaped and is provided with a detachment pressure head 310 that is pressed against the upper surface of the defective ultra-small LED chip FC with a second adhesive layer AL2 having stronger adhesive strength than the first adhesive layer AL1 provided on the bottom surface of the stick, thereby transferring and removing the defective ultra-small LED chip FC attached on the first adhesive layer AL1 to the second adhesive layer AL2.

[0041] 3a to 3f, according to one embodiment, the second adhesive layer AL2 is provided on one side of the first transfer film TF1, which is transported reel-to-reel in the horizontal direction. That is, the second adhesive layer AL2 can be realized in the form of an adhesive tape for transfer, which is applied to one side of the first transfer film TF1.

[0042] In this state, the detachment pressure head 310 selectively applies pressure vertically to the other side of the first transfer film TF1, thereby transferring the defective ultra-small LED chips FC to the second adhesive layer AL2 and removing them on the first adhesive layer AL1, and then the first transfer film TF1, after the removal, is transported reel-to-reel at a certain distance horizontally for the next detachment transfer operation.

[0043] Furthermore, a driving unit 320 for moving the detachment pressure head 310 over the substrate S in the X, Y, and Z axis directions is provided.

[0044] According to one embodiment, the driving unit 320 includes a linear transport unit (not shown) that moves the detachment pressure head 310 on a plane in the X and Y axis directions, and an up-down driving unit (not shown) that moves the detachment pressure head 310 up and down in the Z axis direction.

[0045] An attach pressure head 330 is installed on one side of the detach pressure head 310 .

[0046] The attachment pressure head 330 is moved in the X, Y, and Z axis directions on the substrate S by the driving unit 320, and takes on the overall shape of a micro-sized stick, with a third adhesive layer AL3, which has weaker adhesive strength than the first adhesive layer AL1, provided on the bottom surface of the stick.

[0047] At this time, a replacement normal micro-miniature LED chip RC for rework is attached to the bottom surface of the third adhesive layer AL3, and is pressed onto the first adhesive layer AL1 of the defective micro-miniature LED chip FC removed by the detachment pressure head 310, thereby transferring the replacement normal micro-miniature LED chip RC attached to the third adhesive layer AL3 to the first adhesive layer AL1 and recovering it.

[0048] 3a to 3f, according to one embodiment, the third adhesive layer AL3 is provided on one side of the second transfer film TF2, which is transported reel-to-reel in the horizontal direction. That is, the third adhesive layer AL3 can be realized in the form of an adhesive tape for transfer, which is applied to one side of the second transfer film TF2.

[0049] In this state, the attachment pressure head 330 selectively applies pressure to the other side of the second transfer film TF2 from the vertical direction to transfer and restore the replacement normal ultra-small LED chip RC to the first adhesive layer AL1, and then the second transfer film TF2, which has completed the restoration, is transported reel-to-reel at a certain distance horizontally for the next attachment transfer operation.

[0050] In this case, according to one embodiment, the substrate S may be a flexible substrate.

[0051] Furthermore, according to one embodiment, the first adhesive layer AL1 formed between the substrate S and the ultra-small LED chip, the second adhesive layer AL2 provided on the detachment pressure head 310, and the third adhesive layer AL3 provided on the attachment pressure head 330 may be adhesives that can be attached and peeled off multiple times, i.e., can be repeatedly detached and attached.

[0052] Furthermore, according to one embodiment, the first adhesive layer AL1, the second adhesive layer AL2, and the third adhesive layer AL3 may be adhesives containing acrylate or silicone as raw materials, ester rubber, phenolic resin, etc. as auxiliary agents, to which low molecular weight substances such as polyisobutylene are added, but this is not limited to this.

[0053] According to another embodiment, the first adhesive layer AL1 may be a hot-melt adhesive that selectively imparts adhesive strength or adhesion strength by applying heat or energy.

[0054] Furthermore, according to one embodiment, the first adhesive layer AL1, the second adhesive layer AL2, and the third adhesive layer AL3 are formed by applying liquid adhesive to the top surface of the substrate S or the bottom surface of the detachment pressure head 310 or the attachment pressure head 330, respectively, using a dispenser device.

[0055] Meanwhile, according to another embodiment, the first adhesive layer AL1 may be a conductive adhesive.

[0056] More specifically, the first adhesive layer AL1 may be a conductive adhesive containing one or more metallic fillers such as silver, gold, copper, nickel, palladium, platinum, iron, tungsten, molybdenum, zinc or aluminum that do not contain lead (Pb), or conductive carbon materials such as carbon nanotubes, graphene, graphite or carbon black.

[0057] In the case of the metal filler, the melting point is higher than that of lead, so there is a risk that functional components may be thermally damaged during the mounting process. Therefore, a conductive adhesive that does not contain lead and can be used for low-temperature bonding at around 150°C may also be used.

[0058] More specifically, the conductive adhesive may contain a low content of the above-mentioned expensive conductive filler but have a corresponding conductivity and at the same time have excellent thermal or physical properties, such as a conductive nanomaterial with a one-dimensional structure, i.e., a material such as metal nanowires or carbon nanotubes, thereby reducing the content of the expensive conductive filler and improving mechanical properties.

[0059]

[0060] Hereinafter, the rework method for micro LED chips using the transfer method of the present invention will be described step by step with reference to FIGS. 3a to 3f.

[0061] Step (a) (see Figure 3a): A detachment pressure head 310, which is in the form of a stick and has a second adhesive layer AL2 on the bottom surface of which is stronger adhesive than the first adhesive layer AL1, moves and positions the defective ultra-small LED chip FC to be reworked, which has been transferred to the first adhesive layer AL1 on the substrate S.

[0062] At this time, the screening inspection of the defective micro-miniature LED chips FC can be performed by a separate vision unit (not shown).

[0063] Step (b) (see Figure 3b): Next, the detachment pressure head 310 is lowered onto the defective ultra-small LED chip FC, so that the second adhesive layer AL2 provided on the bottom surface of the detachment pressure head 310 is pressed against the upper surface of the defective ultra-small LED chip FC while in contact with it.

[0064] Step (c) (see FIG. 3c): As the detachment pressure head 310 rises again, the defective ultra-small LED chip FC that has been transferred to the second adhesive layer AL2, which has stronger adhesive strength than the first adhesive layer AL1, is separated from the first adhesive layer AL1 and rises together with the detachment pressure head 310 while still attached to the second adhesive layer AL2.

[0065] That is, as the defective micro-small LED chip FC is raised while attached to the second adhesive layer AL2, it is separated from the first adhesive layer AL1 and removed. At this time, only the first adhesive layer AL1 remains on the upper surface of the substrate S.

[0066] Step (d) (see FIG. 3d): Next, an attachment pressure head 330 is placed above the first adhesive layer AL1 from which the defective micro-small LED chips FC have been removed in step (c).

[0067] The attachment pressure head 330 is stick-shaped as described above, and a third adhesive layer AL3 having a weaker adhesive strength than the first adhesive layer AL1 is provided on the bottom surface of the stick, and a replacement normal micro-small LED chip RC is attached to the bottom surface of the third adhesive layer AL3.

[0068] That is, in order to replace the removed defective microminiature LED chip FC with a normal replacement microminiature LED chip RC, the attachment pressure head 330 is positioned above the first adhesive layer AL1 from which the defective microminiature LED chip FC has been removed.

[0069] Step (e) (see FIG. 3e): Next, the attachment pressure head 330 descends to press and apply pressure to the first adhesive layer AL1 from which the defective ultra-small LED chip FC has been removed, thereby transferring the replacement normal ultra-small LED chip RC that was attached to the third adhesive layer AL3 at the bottom of the attachment pressure head 330 to the first adhesive layer AL1 from which the defective ultra-small LED chip FC has been removed.

[0070] Step (f) (see FIG. 3f): Finally, as the attachment pressure head 330 rises, it moves upward and returns to its original position, leaving only the replacement normal micro-miniature LED chip RC attached to the first adhesive layer AL1 from which the defective micro-miniature LED chip FC was removed.

[0071] In summary, the detachment pressure head 310 is positioned above a specific defective micro-miniature LED chip (FC) that has been misaligned, and then lowered, so that the second adhesive layer (AL2) of the detachment pressure head 310 comes into contact with and pressurizes the top surface of the defective micro-miniature LED chip (FC).

[0072] In this state, since the adhesive strength of the second adhesive layer (AL2) is stronger than that of the first adhesive layer (AL1), the defective micro LED chip (FC) where the misalignment occurred is transferred (attached) to the second adhesive layer (AL2) of the detaching pressure head 310 and removed (separated) from the substrate S while rising together with the detaching pressure head 310.

[0073] Next, the attachment pressure head 330 is positioned at the location (upper surface of the first adhesive layer) where the misaligned defective micro-miniature LED chip (FC) was removed, and then the attachment pressure head descends and attaches to the third adhesive layer (AL3) to transfer the ready replacement normal micro-miniature LED chip (RC) to the location (upper surface of the first adhesive layer) where the misaligned defective micro-miniature LED chip (FC) was removed, thereby completing the replacement of the LED chip.

[0074]

[0075] It should be noted that the present invention is not limited to the above-described embodiment, and similar effects can be achieved even when the detailed configuration, number, and layout of the device are changed. Therefore, it is clearly stated that a person with ordinary knowledge in the relevant technical field can add, delete, and modify various configurations within the scope of the technical concept of the present invention.

Claims

1. An ultra-small LED chip rework device for removing defective ultra-small LED chips that are misaligned or have performance defects from among a plurality of ultra-small LED chips transferred onto a substrate by a first adhesive layer, a detachment pressure head that is stick-shaped and has a second adhesive layer on the bottom surface of the stick-shaped member that is stronger in adhesive strength than the first adhesive layer, and that applies pressure to the top surface of the defective micro-miniature LED chip to transfer the defective micro-miniature LED chip attached to the first adhesive layer to the second adhesive layer, thereby removing the defective micro-miniature LED chip; a drive unit that moves the detachment pressure head in X, Y, and Z axes directions on the substrate; an attaching pressure head that is movable in X, Y, and Z axis directions on the substrate by the driving unit, is configured in a stick shape, has a third adhesive layer on a bottom surface of the stick shape, the third adhesive layer having a weaker adhesive strength than the first adhesive layer, and has a replacement normal microminiature LED chip attached to the bottom surface of the third adhesive layer, and is pressed onto the first adhesive layer of the defective microminiature LED chip removed by the detaching pressure head to transfer the normal microminiature LED chip attached to the third adhesive layer to the first adhesive layer, thereby recovering the defective microminiature LED chip; the drive unit includes a linear transport unit for moving the detachment pressure head in X and Y axis directions, and an up-down drive unit for raising and lowering the detachment pressure head in Z axis direction; Rework equipment for ultra-small LED chips using the transfer method.

2. The second adhesive layer is provided in a state where it is formed on one side of a first transfer film that is transported reel-to-reel in a horizontal direction, and the detachment pressure head selectively presses the other side of the first transfer film in a vertical direction. A rework device for ultra-small LED chips using the transfer method according to claim 1.

3. the third adhesive layer is provided in a state of being formed on one surface of a second transfer film that is transported reel-to-reel in a horizontal direction, and the attachment pressure head selectively presses the other surface of the second transfer film in a vertical direction. A rework device for ultra-small LED chips using the transfer method according to claim 1.

4. (a) a step of moving and positioning a detachment pressure head provided in a stick shape above a defective micro-miniature LED chip to be reworked, which has been transferred to a first adhesive layer on a substrate, and having a second adhesive layer on the bottom surface of the stick shape that is stronger in adhesive strength than the first adhesive layer; (b) the detachment pressure head is lowered to press and apply pressure to the first adhesive layer while the second adhesive layer is connected to the defective microminiature LED chip; (c) as the detachment pressure head rises, the defective micro-miniature LED chips transferred to the second adhesive layer having a stronger adhesive strength than the first adhesive layer are separated from the first adhesive layer and rise together with the detachment pressure head while being attached to the second adhesive layer; After the step (c), (d) positioning the stick-shaped attachment pressure head, which has a third adhesive layer on the bottom surface of the stick, the third adhesive layer having a weaker adhesive strength than the first adhesive layer, and a replacement normal microminiature LED chip attached to the bottom surface of the third adhesive layer, above the first adhesive layer from which the defective microminiature LED chip has been removed; (e) a step of transferring the normal replacement microminiature LED chip attached to the third adhesive layer to the first adhesive layer by lowering the attachment pressure head and applying pressure to the first adhesive layer from which the defective microminiature LED chip has been removed, thereby recovering the normal replacement microminiature LED chip attached to the third adhesive layer; (f) the attachment pressure head from which the replacement normal microminiature LED chip has been separated is raised again to its original position, A method for reworking ultra-small LED chips using the transfer method.

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