Investigation of ESD transient EMI causing spurious clock track read transitions during servo-write

A simple loop antenna detector was used to successfully troubleshoot reference clock failures during servo-write that were caused by the EMI from distant metal-to-metal ESD events. Covering one metal surface with a dissipative material reduced the discharge rate and EMI. This approach proved effective for stopping such ESD EMI induced production yield loss. This case study concludes that it is necessary to also control those areas immediately adjacent to ESD protected production lines to protect these areas against strong indirect ESD EMI.