Stress Analysis of CIP and CPP Read Head

Abstract

The stress in a read head in a hard disk drive was investigated by using finite element method (FEM) calculations. We compared the structurally induced effect of stress in a current-in-plane (CIP) structure and in a current-perpendicular-to-plane (CPP) structure. We found that electrodes in the CIP structure produced a large amount of in-plane anisotropic stress at the pinned layer. However, anisotropic stress induced in the CPP structure by the sensor-side material such as hard bias was less than that in the CIP structure. This was because the CPP structure did not have thick electrodes on the sensor side.