Transfer of Tactile Sensors Using Stiction Effect Temporary Handling

Area of Science:

• Materials Science
• Electrical Engineering
• Mechanical Engineering

Background:

• Microelectromechanical-system (MEMS) and CMOS integration presents challenges in process complexity and reliability.
• Current methods for tactile sensor transfer often involve intricate steps and material limitations.

Purpose of the Study:

• To introduce a novel method for tactile sensor transfer using stiction effect temporary handling (SETH).
• To simplify MEMS/CMOS integration, enhance process reliability, improve electrical performance, and reduce material constraints.

Main Methods:

• Fabrication of tactile sensor and reroute substrate separately.
• Temporary bonding of tactile sensor to substrate using stiction effect.
• Au-Si eutectic flip-chip bonding followed by mechanical release of temporary structures.
• Characterization of transferred tactile sensor size, bonding misalignment, sensitivity, and strength.

Main Results:

• Successful transfer of micro-tactile sensors (180 μm × 180 μm × 1.2 μm) with high yield (90%).
• Achieved high sensitivity (up to 0.27 mV/V/kPa) and bonding shear strength (30.74 MPa).
• Demonstrated minimal flip-chip bonding misalignment (approx. 1.5 μm) and controlled stress levels.

Conclusions:

• The SETH method offers a simplified and reliable approach for integrating micro-tactile sensors with MEMS/CMOS.
• The technique overcomes material limitations and enhances the performance of micro-scale sensor systems.
• This advancement holds potential for next-generation electronic devices requiring sophisticated tactile sensing capabilities.