Hybrid Microassembly with Surface Tension Driven Self-alignment: Handling Strategies and Micro-fabricated Patterns

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School of Electrical Engineering | Doctoral thesis (article-based) | Defence date: 2013-08-23
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Aalto University publication series DOCTORAL DISSERTATIONS, 117/2013
Hybrid microassembly combines self-assembly technology with traditional robotic pick-and-place technology or other robotic feeding mechanics to construct microsystems. In a typical hybrid microassembly process, a micro part is brought adjacent to the assembly site by a robot handling tool at a high speed but with a relatively low precision, and liquid droplets dispensed by a dispenser at the assembly site align the part at a higher precision. By combing both the robotic pick-and-place technique and self-assembly technique, hybrid microassembly technique can achieve high speed and high precision simultaneously. This thesis explores the adaptability of hybrid microassembly technique by investigating different hybrid microassembly methods and different types of the patterns. Three hybrid microassembly approaches have been investigated: 1) droplet assisted hybrid microassembly, 2) water mist induced hybrid microassembly and 3) hybrid microassembly with forced wetting. The droplet assisted hybrid microassembly has been studied using patterns with segments and patterns with jagged edges. Parallel microassembly of microchips with water mist induced hybrid microassembly has also been explored. Hybrid microassembly on hydrophobic receptor site with super-hydrophobic substrate has been experimentally investigated with two forced wetting techniques. Four different types of patterns have been investigated for hybrid microassembly technique: (a) oleophilic/phobic patterns, (2) hydrophobic/super-hydrophobic patterns, (3) segmented patterns and (4) patterns with jagged edges. Hybrid microassembly has been studied on a new patterned oleophilic/oleophobic surface using adhesive droplet in ambient air environment. A patterned hydrophobic/super-hydrophobic surface has also been investigated and hybrid microassembly has been demonstrated with both water and adhesive. Application relevant patterns such as segmented patterns and patterns with jagged edges have been investigated. In summary, this thesis shows that hybrid microassembly can adapt to large varieties of patterns. Several new hybrid microassembly methods are developed and demonstrated. Such a wide adaptability and a variety of the processes indicate that hybrid microassembly can be a very promising approach for many potential applications, such as integration of surface emitting lasers, integration of small dies and 3D integration of chips with high density pin counts.
Supervising professor
Koivo, Heikki, Prof., Aalto University, Department of Automation and Systems Technology, Finland
Thesis advisor
Zhou, Quan, Assistant Professor, Aalto University, Department of Automation and Systems Technology, Finland
hybrid microassembly, droplet self-alignment, surface tension, self-assembly
Other note
  • [Publication 1]: Bo Chang, Ali Shah, Iiris Routa, Harri Lipsanen, and Quan Zhou, “Surface-tension driven self-assembly of microchips on hydrophobic receptor sites with water using forced wetting,” Applied Physics Letters, vol. 101, no. 11, p. 114105, 2012.
  • [Publication 2]: Bo Chang, Veikko Sariola, Susanna Aura, Robin H. A. Ras, Maria Klonner, Harri Lipsanen, and Quan Zhou, “Capillary-driven self-assembly of microchips on oleophilic/oleophobic patterned surface using adhesive droplet in ambient air,” Applied Physics Letters, vol. 99, no. 3, p. 034104, 2011.
  • [Publication 3]: Bo Chang, Iiris Routa, Veikko Sariola, and Quan Zhou, “Self-alignment of RFID dies on four-pad patterns with water droplet for sparse self-assembly,” J. of Micromechanics and Microengineering, vol. 21, no. 9, p. 095024, 2011.
  • [Publication 4]: Bo Chang, Veikko Sariola, Mirva Jääskeläinen, and Quan Zhou, “Self-alignment in the stacking of microchips with mist-induced water droplets,” J. of Micromechanics and Microengineering, vol. 21, no. 1, p. 015016, 2011.
  • [Publication 5]: Ali Shah, Bo Chang, Sami Suihkonen, Quan Zhou, and Harri Lipsanen, “Surface-tension driven self-alignment of microchips on black silicon based hybrid template in ambient air,” J. of Microelectromechanical Systems, vol. 22, no. 3, p. 739-746, 2013.
  • [Publication 6]: Bo Chang, Antti Virta, and Quan Zhou, “Hybrid microassembly for massively parallel assembly of microchips with water mist,” in Proc. Int. Conf. on Manipulation, Manufacturing and Measurement on the Nanoscale, 3M-NANO'12, September, 2012, pp. 38-43.
  • [Publication 7]: Bo Chang, Mirva Jääskeläinen, and Quan Zhou, “Hybrid microassembly of chips on low precision patterns assisted by capillary self-alignment,” in Proc. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, IEEE-IROS'11, October, 2011, pp. 907-912.
  • [Publication 8]: Bo Chang, Ville Liimatainen, Iiris Routa, and Quan Zhou, “High-accuracy positioning of microchips on patterns with jagged edges using hybrid microassembly,” in Proc. IEEE Int. Conf. on Mechatronics and Automation, IEEE-ICMA'12, August, 2012, pp. 807-812.
  • [Publication 9]: Bo Chang, Mirva Jääskeläinen, and Quan Zhou, “Hybrid micro assembly of microchips on segmented patterns,” in Proc. IEEE Int. Conf. on Automation Science and Engineering, IEEE-CASE'10, 2010, pp. 15-20.
  • [Publication 10]: Bo Chang, Mirva Jääskeläinen, and Quan Zhou, “Microassembly combining pick-and-place and water mist,” in Int. Symposium on Micro-NanoMechatronics and Human Science, MHS'10, 2010, pp. 333-337.