MAGNETIC DISK UNIT, PREAMPLIFIER FOR MAGNETIC DISK UNIT, AND FLEXIBLE PRINTED CABLE ASSEMBLY FOR MAGNETIC DISK UNIT

摘要

PROBLEM TO BE SOLVED: To improve the cost, packaging property and reliability of a magnetic disk unit for adjusting the floating height of a magnetic head slider according to the using height by using an atmospheric pressure sensor and a heater.;SOLUTION: The preamplifier 7 is a semiconductor chip three-dimensionally stacked and formed with thin film circuits on a bulk silicon wafer 7a. The atmospheric pressure sensor 7f is integrally formed by a half semiconductor process on the semiconductor chip. The atmospheric pressure sensor 7f is constituted of an isolated space 7g, a diaphragm 7h which is deformed when the pressure difference between the isolated space 7g and the outside changes, and a lower electrode 7i and upper electrode 7j which detect the change of an electrostatic capacity when the pressure difference between the isolated space 7g and the outside changes. The preamplifier 7 integrally formed with the atmospheric pressure sensor 7f is mounted on an FPC 6 in such a manner that the atmospheric pressure sensor 7f faces the flexible printed cable (FPC) 6. A through-hole 6f is disposed in a portion of the FPC facing the atmospheric pressure sensor 7f in order to introduce the atmospheric pressure of the use environment into the diaphragm 7h of the atmospheric pressure sensor 7f.;COPYRIGHT: (C)2008,JPO&INPIT