Selective MicroLED Harvest for Defect-Free Fluidic Assembly

The patent applies preliminary action by performing defect identification and removal on the microLED wafer before the assembly process. The wet chemical etch method removes defective microLEDs and debris from the wafer surface in advance, creating a clean suspension free of defects before fluidic assembly begins. This eliminates the need for expensive post-assembly defect detection and mechanical replacement tools.

The patent replaces mechanical pick-and-place defect removal methods with a chemical etching process. Instead of using mechanical tools to physically remove defective microLEDs, the invention uses wet chemical etchants that selectively dissolve defective devices and debris, leaving functional microLEDs intact. This chemical approach is faster, cheaper, and more suitable for high-volume microLED production.

The patent replaces expensive mechanical defect removal tools with a simple wet chemical etching process. The etchant solution selectively removes defective microLEDs and debris through chemical dissolution rather than mechanical force. This approach uses inexpensive chemical reagents and simple processing equipment, dramatically reducing both capital equipment costs and operational expenses while maintaining display quality.

The patent employs disposable wet chemical etchants that can be easily discarded after use, replacing the need for expensive, complex mechanical removal systems. The chemical process uses simple, inexpensive reagents that work effectively in a single-use manner, eliminating the need for costly, precision mechanical tools required for defect removal.

The patent performs defect detection and removal preliminarily on the wafer level before individual microLEDs are packaged and assembled. By etching away defective devices in bulk on the wafer substrate, the process identifies and eliminates defects en masse rather than testing each microLED individually afterward. This preliminary bulk treatment dramatically reduces the time required for defect management in UHD display production.

The patent merges multiple defect detection and removal operations into a single wet chemical etching step. Instead of separate testing and removal processes for each microLED, the invention combines defect identification and elimination into one unified chemical treatment applied to the entire wafer, significantly reducing total processing time.

The patent replaces mechanical handling of microLEDs with a fluidic assembly process. After wet chemical etching removes defects, functional microLEDs are transferred to a liquid suspension and delivered to the substrate through fluid flow rather than mechanical manipulation. This fluid-based approach minimizes physical contact and mechanical stress on the fragile microLEDs, reducing damage and loss during assembly.

The patent uses hydraulic principles by suspending microLEDs in a liquid medium and using fluid flow to transport and position them on the substrate. This fluidic handling system replaces mechanical grippers and manipulators, providing gentle, contactless handling that protects the integrity of small microLED devices throughout the assembly process.