A light-emitting element ink and a method of manufacturing a display device using the light-emitting element ink are provided. The light-emitting element ink comprises a solvent, a dispersant mixed with the solvent, and a plurality of light-emitting elements dispersed in the solvent, each of the light-emitting elements including a plurality of semiconductor layers and an insulating film surrounding parts of outer surfaces of the semiconductor layers, wherein the dispersant includes an aqueous dispersant or an organic dispersant, if the dispersant is the aqueous dispersant, the solvent has a hydrogen bonding parameter, of Hansen's solubility parameters, of less than 7, and if the dispersant is the organic dispersant, the solvent has a hydrogen bonding parameter, of Hansen's solubility parameters, of 7 or greater.

A display device may include a pixel disposed in a display area. The pixel may include: a first electrode extending in a first direction; a second electrode including a first electrode part spaced apart from the first electrode in a direction intersecting with the first direction and extending in the first direction, a second electrode part extending from the first electrode part in a second direction, and a third electrode part extending form the second electrode part in the first direction; a third electrode including at least one area spaced apart from the third electrode part in the direction intersecting with the first direction and extending in the first direction; a first light emitting element connected between the first electrode and the second electrode; and a second light emitting element connected between the second electrode and the third electrode.

The present invention relates to a system for transferring a micro LED, the system not only releasing a grip force of a transfer head when transferring a micro LED to a substrate but also applying an additional force to the micro LED from below the substrate to attract the micro LED onto the substrate.

Disclosed are methods and systems of controlling the placement of micro-objects on the surface of a micro-assembler. Control patterns may be used to cause electrodes of the micro-assembler to generate dielectrophoretic (DEP) and electrophoretic (EP) forces which may be used to manipulate, move, position, or orient one or more micro-objects on the surface of the micro-assembler. The control patterns may be part of a library of control patterns.

Disclosed herein are techniques for transferring particles in a pattern. In one implementation, a particle-transferring system includes a first substrate comprising a first surface configured to support a plurality of particles in a non-uniform pattern, and a particle transfer unit configured to remove the plurality of particles from the first surface in response to the plurality of particles being within a first gap. The system also includes a second substrate configured to remove the plurality of particles from the particle transfer unit and secure the plurality of particles to the second surface in response to the plurality of particles being within a second gap. The particle transfer unit is configured to transfer the plurality of particles and maintain the non-uniform pattern regardless of the positions of the plurality of particles, which are not predefined to fit features of the particle transfer unit.

Discussed is a device for self-assembling semiconductor light-emitting diodes for placing the semiconductor light-emitting diodes at predetermined positions on a substrate by using an electric field and a magnetic field, the substrate being accommodated in an assembly chamber accommodating a fluid, the device including a substrate chuck configured to dispose the substrate at an assembly position, wherein the substrate chuck includes a substrate support part configured to support the substrate on which an assembly electrode is formed, a rotating part configured to support the substrate support part, and a controller configured to control driving of the substrate chuck, wherein the substrate support part includes micro-holes for injecting a gas between the fluid and the substrate, and wherein the controller controls whether the gas is injected through the micro-holes according to whether the substrate is raised or lowered.

The present application discloses a method for transferring a plurality of micro light emitting diodes (micro LEDs) to a target substrate. The method includes providing a first substrate having an array of the plurality of micro LEDs; providing a target substrate having a bonding layer having a plurality of bonding contacts; applying the plurality of bonding contacts with an electrical potential; aligning the plurality of micro LEDs with the plurality of bonding contacts having the electrical potential; and transferring the plurality of micro LEDs in the first substrate onto the target substrate.

Discussed is a device for self-assembling semiconductor light-emitting diodes includes a substrate chuck that is provided in an assembly chamber and supports a substrate and disposes the substrate at an assembly position, wherein the substrate chuck sucks or injects a gas present between the substrate and a fluid during loading and unloading of the substrate.

An ink leveling device includes a stage on which a target substrate is disposed, base frames disposed at sides of the stage, moving members coupled to the base frames and movable upward and downward, and at least one plate coupled to the moving members and disposed to press the target substrate. Light-emitting element ink is disposed on the target substrate.

A display device includes a first substrate, a first electrode on the first substrate, a second electrode on the first substrate and spaced from the first electrode, a plurality of light-emitting elements each having respective end portions on the first and second electrodes, a first transistor having a first end connected to the first electrode and a second end grounded, and a second transistor having a first end connected to the second electrode and a second end grounded, wherein the first transistor is forward-biased to the first electrode, and the second transistor is reverse-biased to the second electrode.