Hybrid microassembly for massively parallel assembly of microchips with water mist

This paper proposes a hybrid microassembly technique for massively parallel assembly of 200μm × 200μm × 30μm SU-8 chips. The hybrid microassembly technique combines the robotic pick-and-place technique and water mist induced self-assembly technique. The robotic handling tool is used to place microchips roughly on chips of the same size at a fast speed, and then water mist composed of microscopic droplets is delivered to achieve high accuracy and massively parallel alignments. The results indicate the hybrid assembly technique is promising for assembly of microchips. A 200μm × 200μm × 70μm SU-8 chip is assembled on the top of another SU-8 chip of the same size; where the success rate can reach 80% with bias as high as 130μm in x- and y directions. We have demonstrated that the proposed technique in assembly a matrix of 30 200μm × 200μm SU-8 chips. The results also show that alignment can reach sub micrometer accuracy.