Recently, the miniature of electric products such as notebook, cellular-phone etc. is apparently appeared, due to the smaller size of the semiconductor chips. As the size of chip gets smaller, the circuit could be easily damaged by the slightest influence, therefore it is important to investigate the machining quality of $mu$ BGA. This paper deals with machining characteristics of the $mu$ BGA singulation. The relationships between the singulation face and machining quality of the $mu$ BGA singulation are investigated. It is confirmed that machining quality improves as the singulation force decreases.