Micro-spring force characterization and applications in integrated circuit packaging and scanning probe MEMS metrology
Micro-springs are characterized and demonstrated in in-tegrated circuit (IC) packaging and microelectromechanical system (MEMS) metrology applications. The springs are based on lithographically defined stress-engineered films and are compliant, electrically conducting and have micrometer scale dimensions. The force-displacement is experimentally measured and found to have constant stiffness through the majority of compression. Fretting experiments are performed to investigate the potential for intermittent electrical contact when the springs are used as a solderless pressure contact for integrated circuit packaging. While operating at < 1mN of force, orders of magnitude lower than macroscopic connectors, no glitches slower than 4 nsec are observed for thousands of shake cycles. The springs are also demonstrated as scanning probes for non-destructive imaging of high-aspect ratio MEMS structures. Sidewall linescans and tapping mode images in deep silicon trenches are presented using tip heights over ten times taller than commercial probes.
Chow, E. M. ; Hantschel, T. ; Klein, K.; Fork, D. K. ; Chua, C. L. ; Wong, L. ; Van Schuylenbergh, K. Micro-spring force characterization and applications in integrated circuit packaging and scanning probe MEMS metrology. 12th International Conference on Solid-State Sensors, Actuators, and Microsystems (Transducers '03); 2003 June 8-12; Boston; MA; USA. Piscataway NJ: IEEE; 2003: 408-411.