DC Current Path Optimization for Energy-Assisted Magnetic Recording

Abstract

Energy assisted perpendicular magnetic recording (ePMR) technology was utilized to ship 18–20 TB hard disk drive (HDD) by Western Digital in 2020 and is considered to be the technology for the future nearline products [1]–[2]. Magnetic writer used in ePMR technology carry the DC current by utilizing main pole (MP) and trailing side shield (TS) as lead structure connected through a small stack inside the trailing side gap region. DC current flow inside the magnetic writer volume helps improve flux jitter [3].