Journal of the Institute of Electronics Engineers of Korea SD (대한전자공학회논문지SD)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Fabrication of Electrostatic Track-Following Microactuator for Hard Disk Drive Using SOI

SOI를 이용한 하드 디스크 드라이브용 정전형 트랙 추적 마이크로 액추에이터의 제작

  • Kim, Bong-Hwan (School of Electrical Engineering, Seoul National University) ;
  • Chun, Kuk-Jin (School of Electrical Engineering, Seoul National University) ;
  • Seong, Woo-Kyeong (Department of Molecular Science and Technology, Ajou University) ;
  • Lee, Hyo-Jung (Department of Molecular Science and Technology, Ajou University)
  • 김봉환 (서울大學校 電氣工學部) ;
  • 전국진 (서울大學校 電氣工學部) ;
  • 성우경 (亞洲大學校 分子科學技術學科) ;
  • 이효정 (亞洲大學校 分子科學技術學科)
  • Published : 2000.08.01
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Abstract

We have achieved a high aspect ratio track-following microactuator (TFMA) which is capable of driving 0.3 ${\mu}m$ magnetic head for hard disk drive (HDD). it was fabricated on silicon on insulator (SOI) wafer with 20 ${\mu}m$ trick active silicon and 2 ${\mu}m$ thick thermally grown oxide and piggyback electrostatic principle was used for driving TFMA. The first vibration mode frequency of TFMA was 18.5 kHz which is enough for a recording density of higher than 10 Gb/in$^2$. Its displacement was 1.4 ${\mu}m$ when 15 V dc bias plus 15 V ac sinusoidal driving input was applied and its electrostatic force was 50 N. The fabricated actuator shows 7.51 dB of gain margin and 50.98$^{\circ}$ of phase margin for 2.21 kHz servo-bandwidth.

0.3 g의 하드디스크 드라이브에 사용될 수 있는 마그네틱 헤드를 장착할 수 있는 트랙 추적용 마이크로 액추에이터를 제작하였다. 이 액추에이터는 정전방식을 적용하였으며 2${\mu}m$ 두께의 열산화막과 20${\mu}m$ 두께의 실리콘 막이 직접접합된 SOI 웨이퍼를 이용하여 단지 3장의 마스크만을 사용하여 제작하였다. 고유진동수는 18.5 kHz이고 15 V DC와 15 V AC 전압이 동시에 가해진 상황에서 그 변위가 1.4 ${\mu}m$이였고 이때 30 V일 때 50 N의 정전력을 나타내었다. 또한 2.21 kHz의 서보 주파수 대역에서 이득여유가 7.51 dB이고 위상여유가 50.98$^{\circ}$이였다. 따라서 이 트랙추적 마이크로 액추에이터는 10 Gb/in$^2$의 기록밀도를 요구하는 하드디스크 드라이브에 충분히 이용될 수 있을 것이다.

Keywords

References

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