Analysis of the electrical field effects of AC and DC ionization systems for MR head manufacturing

Electrical ionizers are frequently used in manufacturing areas to reduce the charge on nonconductive materials. A variety of ionizers are available on the market to satisfy the needs of manufacturers of static sensitive products. This paper investigates the electrical fields that are generated by steady-state DC and AC ionizing blower systems that are frequently used in disk drive manufacturing processes. An industry standard charged plate monitor, a low capacitance monitor, and discharge currents from a head-gimbal-assembly (HGA) are used to evaluate the ionization systems. Through this research, it was found that the standard CPM frequently used to evaluate ionization systems was inadequate in its response time to see transient fields generated by AC ionizers. In addition, most electrical ionization systems can drift sufficiently from a zero-volt offset to potentially create damage in very sensitive devices such as MR head assemblies.