• 한국정밀공학회지
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• 제20권7호
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• pp.78-83
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• 2003

Characterization of an ultra precision grinding plate for GMR head manufacturing is performed by measuring frictional forces between the grinding plate and the advanced ceramic Two kinds of methods of producing the precision grinding plates are presented: texturing and micro-channeling. Texturing is effective in terms of production time but micro-channeling excels in quality control. It is found that the frictional coefficient of a precision grinding plate decreases as the impregnation of diamond grain onto the precision-grinding plate progresses, and remains unchanged once the impregnation process is successfully completed, even after 100 revolutions of the precision-grinding plate against the advanced ceramic under 40 N of normal force. Therefore, the measurement of the frictional coefficient can replace costly and time-consuming process of estimating the level of impregnation of diamond grain on the precision-grinding plate, which has been performed by using scanning electron microscope, and be employed as an index to determine the level of impregnation of diamond grain.

• 한국자기학회지
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• 제8권2호
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• pp.99-110
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• 1998

MR head technology from the perspective of read sensor evolution was reviewed. AMR sensors have been developed for last two decades and successfully employed into information storage devices such as disk drives. Development of manufacturable GMR sensors is of emerging technological interest because GMR sensors can further meet the need of ultrahigh recording density. In this review, the mechanisms, materials systems, operating principles of both AMR an GMR sensors, and the head structures were discuseed. Constructing GMR heads with ultrathin sensor materials and complex topographical structures demands unique fabrication and design challenges. The commercialization of GMR heads can only be realized by the succesful implementations of high performance materials, advanced thin film processes, and stable head design.

• 한국자기학회지
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• 제9권2호
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• pp.111-120
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• 1999

RF-마그네트론 스퍼터법으로 제조된 200~1200$\AA$의 Co82Zr6Mo12박막을 회전자장 중에서 열처리할 때 박막의 미세구조 및 표면형상의 변화에 따른 전자기적 특성을 조사하였다. 박막의 두께가 증가할수록 보자력은 감소하는 경향을 보였으나, 포화자화 값의 변화는 나타나지 않았다. 열처리 온도가 30$0^{\circ}C$까지 증가함에 따라 보자력은 박막내부 잔류응력의 감소 및 표면조도의 감소로 인해 감소하였고, 40$0^{\circ}C$에서는 부분적인 결정립성장에 의해 증가하였다. 포화자화 값은 열처리 온도 20$0^{\circ}C$까지 변화를 보이지 않고, 300 및 40$0^{\circ}C$에서는 7.4kG에서 8.0kG로 증가하였는바, 이는 박막내의 미세 Co입자의 석출 및 성장에 기인하였다. 전기비저항은 열처리 온도가 증가함에 따라 감소하였으며, 자기저항값은 거의 0cm에 가까운 음의 값을 보였다. 주파수 변화에 따른 박막의 유효투자율은 30$0^{\circ}C$ 열처리시 1200으로 최대값을 나타냈다. 이상에서 박막을 실제적인 자기저항 헤드의 바이어스층으로 응용을 고려시, 최적 열처리조건은 400Oe의 회전자장 중 30$0^{\circ}C$에서 1시간 열처리할 때로 나타났다.