Laser-Assisted Mist Capillary Self-Alignment

Abstract

This paper reports a method combining laser die transfer and mist capillary self-alignment. The laser die transfer technique is employed to feed selected microchips from a thermal release tape onto a receiving substrate and mist capillary self-alignment is applied to align the microchips to the predefined receptor sites on the substrate in high-accuracy. The parameters for a low-power laser die transfer process have been investigated and experimentally optimized. The acting forces during the mist-induced capillary self-alignment process have been analyzed and the critical volume enabling capillary self-alignment has been estimated theoretically and experimentally. We have demonstrated that microchips can be transferred onto receptor sites in 300–400 ms using a low-power laser (100 mW), and chips can self-align to the corresponding receptor sites in parallel with alignment accuracy of 1.4 ± 0.8 μm. The proposed technique has great potential in high-throughput and high-accuracy assembly of micro devices. This paper is extended from an early conference paper (MARSS 2017).

Surface Tension-Based Alignment of Microfibers on Hydrophilic–Superhydrophobic Grooved Surfaces

“…Despite the impressive results achieved so far, it is still challenging to precisely control the spacing of two individual microfibers and the orientation of each microfiber and construct more complex patterns. Previously, our research group has reported a hybrid microassembly technique [21][22][23][24][25] which combines the robotic micro-assembly technique and the surface tension-based self-alignment technique [26][27][28][29][30]. The hybrid microassembly technique has been demonstrated to be able to achieve accurate and fast alignments of microchips, achieving the assembly of 40,000 microchips per hour, with an accuracy higher than 1 µm, and a success rate of 98% [31].…”