Berkovich micro-indentation tests with different loading rates have been performed on the ball grid array solder joint with a Pb-free solder, Sn-4.0Ag-0.5C alloy. The resulting indentation load-depth curves are rate dependent and have varying creep penetration depths during the same hold time. Creep indentation hardness and rate sensitivity have been defined from the concept of "work of indentation". The rate sensitivity of BGA solder joint is 0.0574.