Thesis
Low temperature melting point metals for hot MEMS electrical switching
Washington State University
Master of Science (MS), Washington State University
2007
Handle:
https://hdl.handle.net/2376/100198
Abstract
This thesis presents a method to overcome the mechanical and chemical problems of liquid mercury MEMS electrical switches by using Gallium or Tin, which can be used as solid metal droplets for switches. To understand the structure of Gallium (Ga) and Tin (Sn) micro-droplets for switching operations, the micro-droplets were deposited on the fabricated samples by electroplating, and the behavior is investigated by characterizing the macro structure, adhesion, hardness, and electrical performance of low melting temperature droplets in MEMS structures. The amount of the reacted micro-droplets of Sn and Ga with W was affected by the size of silicon dioxide (SiO2) hole and tungsten (W) target, and thermal reflow time and temperature. The adhesion of the Ga droplet was investigated with contact angles between the droplet and the W dot in the fabricated sample. The contact angles of the deposited Ga droplet were 67.8˚ and 56˚, so it was shown that the Ga droplet had good adhesion with W. The measured resistivity of the Ga droplet was 1.128 x 10-5 Ω cm. This value was similar to the theoretical value (1.00 x 10-5 Ω cm) for Ga, and suggests that the electrodeposited Ga will be suitable for a solid MEMS switch. The hardness of the Ga droplet was obtained with the micro Vickers hardness test, and was 17.2 HV. This suggests a maximum applied stress of 60 MPa can be applied to each droplet in the current configuration.
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Details
- Title
- Low temperature melting point metals for hot MEMS electrical switching
- Creators
- Yoonkap Kim
- Contributors
- David F. Bahr (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900524875701842
- Language
- English
- Resource Type
- Thesis