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Creep measurements in free-standing thin metal film micro-cantilever bending

  • L. I. J. C. Bergers
  • J. P. M. Hoefnagels
  • M. G. D. Geers
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

Creep is a time-dependent deformation mechanism that affects the reliability of metallic MEMS. Examples of metallic MEMS are RF-MEMS capacitors/switches, found in wireless/RF applications. Proper modeling of this mechanism is yet to be achieved, because size-effects that play a role in MEMS are not well understood. To understand this better, a methodology is setup to study creep in Al-Cu alloy thin film micro-cantilevers micro-fabricated in the same MEMS fabrication process as actual RF-MEMS devices. The methodology entails the measurement of time-dependent deflection recovery after maintaining cantilevers at a constant deflection for a prolonged period. Confocal profilometry and a simple mechanical setup with minimal sample handling are applied to control and measure the deformation. Digital image correlation, leveling and kinematics-based averaging algorithms are applied to the measured surface profiles to correct for various errors and improve the precision to yield a precision < 7% of the surface roughness. A set of measurements is presented in which alloy microstructure length scales at the micrometer-level are varied to probe the nature of this creep behavior.

Keywords

Digital Image Correlation Aluminum Film Knife Edge Measured Surface Profile Constant Deflection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • L. I. J. C. Bergers
    • 1
    • 2
    • 3
  • J. P. M. Hoefnagels
    • 1
  • M. G. D. Geers
    • 1
  1. 1.Dept. of Mech. Eng.Eindhoven Univ. of TechnologyEindhovenNL
  2. 2.Foundation for Fundamental Research on MatterUtrechtNL
  3. 3.Materials innovation instituteDelftNL

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