Investigation of electromagnetic interference effects by ESD simulator on test parameters of tunneling magnetic recording heads

• The electrostatic discharge (ESD) has been an important issue for the hard disk drive.
• The electromagnetic interference (EMI) radiated by ESD IEC 61000-4-2 was focused.
• Effects of the EMI on the magnetic recording head were examined.
• The change of parameters of the writer and reader due to the EMI was measured.
• The EMI could not cause any significant affectation on the writer and reader.

Electrostatic discharge (ESD) has been an important issue in the manufacturing processes of hard disk drive. It can also generate electromagnetic interference (EMI) which could possibly damage magnetic recording heads. The aims of this work are to measure the EMI from ESD events and to examine the effects of EMI on the heads. The discharge current and the EMI generated by an ESD simulator were experimentally measured. Also, the EMI was applied to the heads to determine if this can cause changes of head parameters. Our results show that the discharge current waveform is consistent with the theoretical waveform of the IEC ESD standard. Additionally, we found that the EMI applied due to ESD at distances greater than 2 cm does not have any significant effect on the head parameters. Hence, further detailed experiments are proposed to evaluate the EMI effects on recording head parameters in order to improve the measurement methodologies to prevent the degradation of the heads performance and to increase the robustness of the heads.