Micro LED Chemical Bonding Assembly for Defect-Free Pixel Transfer

The patent introduces a temporary substrate as an intermediary component in the transfer process. Micro LEDs are first assembled on the temporary substrate with controlled positioning, then transferred to the wiring substrate. This intermediary step prevents direct fluid flow interference between the LED chip and wiring substrate, eliminating rotation and detachment defects while maintaining high productivity through automated transfer processes.

The patent applies preliminary positioning actions by forming mounting portions on the temporary substrate before LED assembly. These pre-formed structures guide LED placement with precise orientation, preventing rotation defects during subsequent fluid assembly. The preliminary preparation of the temporary substrate enables reliable positioning without requiring complex real-time control during the high-speed transfer process.

The patent segments the transfer process into two distinct stages: first assembling micro LEDs on the temporary substrate, then transferring to the wiring substrate. This segmentation isolates the high-precision assembly step from the potential interference of electric fields in the final substrate, allowing reduced pitch and smaller chip sizes to be assembled with high precision without suffering from electric field interference during the critical assembly phase.

The temporary substrate acts as a mediator that shields micro LEDs from electric field interference during assembly. By performing assembly on the temporary substrate first, the patent eliminates direct exposure to electric fields from the wiring substrate, enabling reliable assembly of high-resolution displays with reduced pitch and smaller chip dimensions.

The patent changes the bonding parameter from conventional mechanical or thermal bonding to chemical bonding through molecular recognition. Specific chemical groups are introduced to create strong, selective bonds between micro LEDs and mounting portions, dramatically improving assembly stability and preventing detachment defects. This parameter change enhances reliability while maintaining process simplicity through a single bonding mechanism that addresses multiple failure modes.

The patent employs composite material structures with specific chemical groups (such as carboxyl, hydroxyl, or amino groups) on the mounting portions and corresponding groups on the micro LEDs. This composite chemical structure enables molecular recognition and strong chemical bonding, creating stable assemblies that resist rotation, double assembly, and detachment while maintaining overall process simplicity.