ESD damage by directly arcing to a MR head
Direct arcing to a MR head occurs when the electric field exceeds the dielectric strength of the insulating material. This usually occurs on the air-bearing surface. It can not be prevented by shunting, insulating, or grounding the leads. The most effective solution is to reduce the field strength near the MR head. Two examples from Headway manufacturing experience are described. In the first case, a glass disk is charged by rubbing with the slider. The charged disk causes arcing between the MR head and a magnetic shield. In the second case, a high-voltage electrode for gold-ball-bond arcs accidentally to the MR head. Symptoms, the arcing mechanism, and the solutions are described.