WAFER’S ELASTODYNAMIC RESPONSE

The purpose of this work is to study the dynamic mechanical response of silicon wafer subjected to low-velocity impact loading. Transient finite element analysis was utilized to obtain the numerical simulated result and was used to check against the experimental findings. Good relationship between each other was observed. A pair of polysilicon microsensors manufactured by the micro-fabrication technique was directly fabricated on the surface of silicon wafer so as to detect the impact induced dynamic strain. A series of low-velocity impact tests utilizing the home-made drop-weight mini-tower tester was conducted. These test results were used to examine the accuracy and adequacy of the current micro strain sensors for stress wave propagation measurements. It is concluded that the difference between the present measured wave speed and the one-dimensional longitudinal wave speed under conditions of plane strain 2(1)L EC ⎛ ⎞ ′ = ⎜ ⎟ρ − ν ⎝ ⎠ were determined to be within 5.6 % for the present low-speed impact problem. A maximum of 10.9 % deviation between the test determined elastic modulus and a reference value (16) of 130 GPa was found based on a series of impact test results. In addition, a difference of 2 % error was reported when we compared the test detected peak stress value after impact initiated (before wave is reflected from the boundary) and the corresponding numerical simulated response