Micro hole drilling in precision production industries requires smaller holes, higher aspect ratios, and higher working speeds. However, the undesirable characteristics of micro drilling are small signal to noise ratios, wandering drill motion, high aspect ratio, and increasing cutting quality as cutting depth increases. In this study, two different types of experiments are performed on single crystal silicon to decrease crack formation. The first experiment compares the efficiency of various micro hole machining processes using ultrasonic impact grinding and micro drilling. The second experiment suggests optimum conditions for the micro drilling process. The experimental results show that micro drilling technology can be effectively used for drilling single crystal silicon.

Reproducibility of injection molding machines are studied at the study of this time. We applied computer aided engineering program so it could generate clamping force, about 1,500 kN, to the nozzle center part of flex link in tie-bar and at this time, we made sure condition of stress distribution and transformation quantity in flex link. The result of computer aided engineering transformation quantity was confirmed that transformation of top area was 247~257 kN and bottom areas was 273~279 kN and also was confirmed that the stresses are distributed in a range of 57~750 N/mm2 from top to the bottom of the surface. This time we could confirm the condition of transformation quantity and stress distribution by enforcing the previously used structure analysis of flex link. And we utilized the reference data to establish important point of section for non destructive test overhaul.