LED Chip Alignment via Capillary Recoil Force

A liquid intermediary is introduced between the microchip and transfer substrate. The liquid forms capillary bridges at the electrical connection pads, generating capillary forces that automatically pull the pads into precise alignment. This intermediary mechanism enables sub-micron alignment accuracy despite the small chip dimensions, resolving the contradiction between miniaturization and alignment precision.

The alignment process is made self-adjusting through capillary forces. When the microchip is placed on the transfer substrate with liquid at the connection pads, the capillary action automatically generates restoring forces that correct misalignment. The system self-aligns without external intervention, achieving precise pad-to-pad registration naturally through the physical properties of the liquid.

The liquid acts as a smart intermediary that provides both alignment function and self-adjustment mechanism. By placing liquid only at the electrical connection pads (not across the entire chip surface), the method achieves precise alignment without requiring complex alignment equipment or multi-step procedures. The liquid's capillary forces naturally guide the pads into registration, simplifying the overall process while dramatically improving accuracy.

The liquid is applied locally only at the electrical connection pads rather than uniformly across the chip. This localized application creates specific capillary zones exactly where alignment is needed, providing high precision at critical points without adding unnecessary complexity elsewhere. The hydrophobic zones surrounding each pad further confine the liquid locally, enhancing the alignment effect precisely where required.