We describe a post-release die separation process for 1 0 0 silicon wafers with polysilicon surface micromachines using a combination of diamond scribing and mechanical breaking. The theoretical basis of scribing is reviewed and the theoretical relationship between scribe force and median crack depth was experimentally verified. Also the relationship between the scribe angle and the median crack depth as well as the stress to fracture is described. Scribe speed and scribe wear were also investigated. The results from our experiments were used to develop a process that had yields above 80% for two types of electrostatic MEMS actuators.