Discussed are a device for self-assembling semiconductor light-emitting diodes, in which the device includes an assembly chamber having a space for accommodating a fluid; a magnetic field forming part having at least one magnet for applying a magnetic force to the semiconductor light-emitting diodes dispersed in the fluid and a moving part for changing positions of the at least one magnet so that the semiconductor light-emitting diodes move in the fluid; and a substrate chuck having a substrate support part configured to support a substrate, and a vertical moving part for lowering the substrate so that one surface of the substrate is in contact with the fluid in a state in which the substrate is supported by the substrate support part, wherein the vertical moving part provided at the substrate chuck lowers the substrate on to the fluid so that a force of buoyancy by the fluid is applied to the substrate.

Discussed is a substrate chuck for allowing one surface of a substrate to be in contact with a fluid, the substrate chuck including a first frame having a hole at a central portion thereof; a second frame having a hole at a central portion thereof and disposed to overlap the first frame; and a frame transfer part configured to vertically move the second frame with respect to the first frame, wherein the first frame includes: a bottom portion at which the hole is formed; and a sidewall portion formed on a peripheral edge of the bottom portion, and wherein a height of the sidewall portion is greater than a depth at which the substrate is placed into the fluid.

Discussed is a substrate chuck including: a substrate support part for supporting a substrate having an assembly electrode; a vertical moving part which moves the substrate so that one surface of the substrate comes in contact with a fluid in a state in which the substrate is supported by the substrate support; an electrode connection part for applying power to the assembly electrode to generate an electric field so that semiconductor light-emitting diodes are placed at the predetermined positions of the substrate in a process of moving the semiconductor light-emitting diodes by a position change of at least one magnet; and a rotating part for rotating the substrate support part around a rotating shaft so that the substrate is placed in an upward or downward direction, wherein the rotating shaft is spaced apart from a center of the substrate support part at a predetermined distance.

A method for transferring a micro device includes: preparing a carrier substrate with the micro device thereon in which an adhesive layer is present between and in contact with the carrier substrate and the micro device; picking up the micro-device from the carrier substrate by a transfer head comprising a force-adjustable glue layer thereon; forming a liquid layer on a receiving substrate; reducing the grip force of the force-adjustable glue layer of the transfer head to be smaller than a force attaching the micro device to the receiving substrate; placing the micro device over the receiving substrate such that the micro device is in contact with the liquid layer and is gripped by a capillary force; and moving the transfer head away from the receiving substrate such that the micro device is detached from the transfer head and is stuck to the receiving substrate.

A method for transferring a micro device is provided. The method includes: preparing a carrier substrate with the micro device thereon, wherein an adhesive layer is between and in contact with the carrier substrate and the micro device; picking up the micro-device from the carrier substrate by a transfer head; forming a liquid layer on a receiving substrate; and placing the micro device over the receiving substrate by the transfer head such that the micro device is in contact with the liquid layer and is gripped by a capillary force; and moving the transfer head away from the receiving substrate such that the micro device is detached from the transfer head and is stuck to the receiving substrate.

Disclosed is a method for fabricating a micro-LED module. The method includes: preparing a circuit board; forming solder bumps on one surface of the circuit board; arranging micro-LED chips on the one surface of the circuit board such that the micro-LED chips are in contact with the solder bumps; heating the solder bumps to bond the micro-LED chips to the one surface of the circuit board through the solder bumps; arranging driver ICs on the other surface of the circuit board such that the driver ICs are in contact with solders on the other surface of the circuit board in a state in which the micro-LED chips are bonded to the circuit board; and heating the solders to bond the driver ICs to the other surface of the circuit board through the solders. The micro-LED chips are arranged on the one surface of the circuit board after the flatness of the circuit board is enhanced.

Embodiments relate to using flux or underfill as a trapping layer for temporarily attaching light emitting diodes (LEDs) to a substrate and heating to simultaneously bond multiple LEDs onto the substrate. The flux or underfill may be selectively coated at the ends of electrodes of the LEDs prior to placing the LEDs on the substrate. Due to adhesive properties of the flux or underfill, multiple LEDs can be placed on and attached to the substrate prior to performing the bonding process. Once LEDs are placed on the substrate, the flux or underfill facilitates formation of metallic contacts between electrodes of the LED and contacts of the substrate during the bonding process. By using the flux or underfill, the formation of metallic contacts can be performed even without applying pressure.

An example of a printed structure comprises a target substrate and a structure protruding from a surface of the target substrate. A component comprising a component substrate separate and independent from the target substrate is disposed in alignment with the structure on the surface of the target substrate within 1 micron of the structure. An example method of making a printed structure comprises providing the target substrate with the structure protruding from the target substrate, a transfer element, and a component adhered to the transfer element. The component comprises a component substrate separate and independent from the target substrate. The transfer element and adhered component move vertically toward the surface of the target substrate and horizontally towards the structure until the component physically contacts the structure or is adhered to the surface of the target substrate. The transfer element is separated from the component.

An apparatus includes a transfer substrate with two or more transfer elements. Each of the transfer elements includes an adhesion element having a first surface adhesion at a first temperature and a second surface adhesion at a second temperature. The second surface adhesion less than the first surface adhesion. Each transfer element has a thermal element operable to change a temperature of the adhesion element in response to an input. A controller is coupled to provide the inputs to the thermal elements of the two or more transfer elements to cause a subset of the transfer elements to selectably hold objects to and release the objects from the transfer substrate in response to changes between the first and second surface adhesion of the subset of the transfer elements.

A method for manufacturing a micro light emitting diode (LED) display is provided. The method includes a first operation of applying a light-to-heat conversion layer to a first surface of a carrier substrate, a second operation of forming a first adhesive layer on the light-to-heat conversion layer a third operation of aligning a plurality of micro LED chips on the first adhesive layer, a fourth operation of positioning the plurality of micro LED chips above a circuit board at a first distance, a fifth operation of radiating a laser to the plurality of micro LED chips, and a sixth operation of causing the first adhesive layer to be deformed by the light-to-heat conversion layer, so that the plurality of micro LED chips are detached from the first adhesive layer to be attached to the circuit board. Various other embodiments are possible.