Laser-Assisted Mist Capillary Self-Alignment.

Bo Chang,Quan Zhou,Mikko Koverola,Zhaofei Zhu

doi:10.3390/mi8120361

Bo Chang, Quan Zhou + Show 2 more

Open Access

https://doi.org/10.3390/mi8120361

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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).

Highlights

High-throughput and high-accuracy microassembly is still a challenging task due to the undesired adhesion forces between micro parts and handling tools at the microscale
Microassembly driven by capillary forces [1,2,3,4,5], electrostatic forces [6], and magnetic forces [7] have been reported for various applications, such as assembly of radio frequency identification (RFID) [8], electrical networks [9], lighting emitting diodes [10], and solar cells [11]
Micro parts need to be transported to the desired assembly sites

Summary

Introduction

High-throughput and high-accuracy microassembly is still a challenging task due to the undesired adhesion forces between micro parts and handling tools at the microscale. Micro parts need to be transported to the desired assembly sites. Hybrid microassembly techniques combining robotic pick-and-place and capillary self-alignment techniques have been reported to achieve fast transportation and accurate self-alignment [17]. Methods, such as transfer printing and the laser die transfer technique, have been reported for high-performance transportation of micro components onto the desired assembly sites.

Results

Conclusion