ESD effect in GMR heads in the trim shunt tab process

The electrostatic discharge (ESD) effect is widely known as a main cause of damage in giant magnetoresistance (GMR) heads (Wallash and Kim, 1995). The transient current may strike the GMR head directly by passing the leads (Li-Yan Zhu, 1999) and this may be prevented by shunting the GMR leads (Bajorek et al, 1995). However, after completing the head gimbal assembly (HGA) production, the shunt leads have to be trimmed in order to test its electrical characteristics. This is thought to cause the ESD effect while trimming the shunt tab of a GMR head, and is investigated here.