Improved Reaction Force Isolation Motor Simulation and Design

Open Access
Gavin, Robert Edward
Area of Honors:
Engineering Science
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Eric Russell Marsh, Thesis Supervisor
  • Barbara Shaw, Honors Advisor
  • Sean Brennan, Honors Advisor
  • Judith A Todd, Faculty Reader
  • wire bonder
  • isolation system
  • simulation
  • Kulicke and Soffa
Extensive research was conducted to improve a motor force isolation system for Kulicke and Soffa Industries, Inc. Kulicke and Soffa designs and manufactures assembly equipment for semiconductor microchips. One of their products is a wire bonder, which bonds gold or copper wire from the semiconductor to the plastic package. The motor produces accelerations up to 20gs and is accurate to a micron. The 20g forces create reaction forces that are transmitted throughout the machine, and if these transmitted forces were reduced the accuracy would improve. Over the summer of 2011 a MATLAB positioning model was created for a motor force isolation system. This system isolates the motor mass such that a reaction force upon the motor creates motor displacement rather than transmitted forces. A problem arose when the experimental results from the proof-of-concept system in the lab were not matching the results of the simulated model on MATLAB. It was decided that the inaccuracy was due to friction that existed in the experimental system that was not taken into account in simulation, and the system parameters may not be accurate. The research conducted for this thesis is the improvement of the simulated system. First, fiction was added to the model since friction is present in the proof of concept experimental system. Input parameters were found by system characterization by creating frequency response functions using experimental data. Certain parameters were found by locating the input parameter values where simulated to theoretical error is minimized. Once the model was corrected a design for an improved isolation system was proposed, where friction is eliminated and isolation frequency is minimized while staying in the limits of the allowable space in the system.