A micro-impression creep machine was designed and developed, adopting a small punch in diameter of 150 ㎛, displacement gage with an accuracy of sub-㎛ scale, and load-cell with an accuracy of mN scale in order to investigate creep behavior of small...
A micro-impression creep machine was designed and developed, adopting a small punch in diameter of 150 ㎛, displacement gage with an accuracy of sub-㎛ scale, and load-cell with an accuracy of mN scale in order to investigate creep behavior of small solder ball in diameter of less than 1 ㎜. Creep behavior of lead-free solder ball(Sn-3.0Ag-0.5Cu) in diameter of 760 ㎛ was investigated in the stress range of 8~60 ㎫ and at 303 K ~ 393 K. The applied load became decreased slightly and continuously in the creep rate of 10?⁴/s range during the current experiments. Also, the machine frame was so sensitive to the environmental temperature that ㎚ scaled displacement recording was unstable according to the change in environmental temperature.