Electrostatic Discharge / Contamination Control in Slider Fabrication through Process Automation and Integration

摘要

The productivity success of hard disk drive (HDD) head lies in the manufacturing capability of slider fabrication with high reliability using extensive electro static discharge (ESD) and contamination control. Both tunneling magnetoresistive (TMR) and heat-assisted magnetic recording (HAMR) sensors are the most extremely ESD sensitive device in the world and due to its nano-size architecture, the built-in ESD protective method being popularly used by semiconductor and electronics industries are not possible. In addition, most conventional ESD control practices being developed for highly sensitive electronic materials are not feasible or useful to protect the TMR or HAMR heads. Also, there is no immediate ESD protection on magnetic head sensor during actual slicing, grinding, lapping, photolithography and testing of slider head. The ESD damage and contamination issue are considered critical reliability concerns of most HDD manufacturers and these have cost hundreds of thousands of US dollars lost from the company when they struck. Therefore, this technical research aims to develop a full proof ESD and contamination control in slider fabrication through development of either a semi or a fully automated process in critical stations. The research will also tap the evaluation of improvised tooling/device to eliminate risks on particular processes and test stations that will fit the requirements of slider fabrication without inducing ESD and contamination to TMR or HAMR heads. Development of automated process is the key to future slider manufacturing, but this must be ESD safe, as well as full proof against transient current, electromagnetic interference (EMI) noise and cross contamination. The above process developments on slider fabrication will be subjected to series of both electrical and visual mechanical test to gather data and to conduct a series of design of experiments and statistical analysis to prove their feasibility on actual slider production and subjective to customer reliability qualification. Since automation and process integration are involved in this research, Promodel software was used to simulate the leadtime reduction and productivity cycle.