Magnetic disk drive, preamplifier for magnetic disk drive, flexible printed cable assembly for magnetic disk drive

• US 7,630,160 B2
• Filed: 01/04/2008
• Issued: 12/08/2009
• Est. Priority Date: 01/05/2007
• Status: Expired due to Fees

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Fujimori, Tsukasa, Tanaka, Hideaki, Satoh, Noriaki, Kurita, Masayuki, Fukuda, Hiroshi, Murai, Masashi
• Primary Examiner(s): WONG, KIN C
• Application Number:
  US12/006,683
• Publication Number:
  US 20080273262A1
• Time in Patent Office: 704 Days
• Field of Search: None
• US Class Current: 360/69
• CPC Class Codes: G11B 33/121 the apparatus comprising a single recording/reproducing device

Abstract

Embodiments of the present invention help to improve the cost, mountability, and reliability of a magnetic disk drive that regulates a fly height of a magnetic head slider correspondingly to the operating altitude of the drive by using an air pressure sensor and a heater. According to one embodiment, a preamplifier is a semiconductor chip formed by three-dimensionally laminating thin film circuits on a bulk silicon wafer. An air pressure sensor is integrally formed on the semiconductor chip through a semiconductor process. The air pressure sensor is configured to include an isolating cavity, a diaphragm that deflecting in response to a change in a pressure difference between the isolating cavity and the outside, and lower and upper electrodes and for detecting variation in electrostatic capacitance. The preamplifier including the air pressure sensor integrally formed therein is attached to a flexible printed cable (FPC) to oppose the FPC. A through-hole is provided in a portion opposite the air pressure sensor of the FPC to introduce air pressure in an operating environment into a diaphragm of the air pressure sensor.

Claims

1. A magnetic disk drive, comprising:

a magnetic disk medium;

a magnetic head slider including a recording element for recording magnetic information onto the magnetic disk medium, a playback element for playing back magnetic information from the magnetic disk medium, and a heater for regulating a distance between each of the recording and playback elements and the information recording medium;

a carriage assembly for supporting the magnetic head slider and for moving the magnetic disk medium along a radial direction of the magnetic disk medium; and

a preamplifier that amplifies and passes a recording signal to the recording element, that amplifies a playback signal of the playback element, and that supplies a current to the heater, the magnetic disk drive being characterized in that the preamplifier includes an air pressure sensor integrally formed with the preamplifier, and regulates an electricity supply amount for the heater in accordance with an output of the air pressure sensor.

2. The magnetic disk drive according to claim 1, characterized in that the preamplifier includes a plurality of air pressure sensors integrally formed with the preamplifier.

3. The magnetic disk drive according to claim 1, characterized in that the air pressure sensor includes a lower electrode, a diaphragm including an upper electrode formed therein, and an isolated cavity between the lower electrode and the diaphragm.

4. The magnetic disk drive according to claim 1, characterized by further comprising a flexible printed cable that is connected to wirelines to which lead wires of the recording element, the playback element, and the heater and that has one end fixed to the carriage assembly, wherein a plane wherein the air pressure sensor of the preamplifier is formed is attached to the flexible printed cable.

5. The magnetic disk drive according to claim 4, characterized in that the flexible printed cable includes a through-hole in a portion opposite the air pressure sensor.

6. The magnetic disk drive according to claim 4, characterized in that the flexible printed cable includes a groove for introducing an external air pressure to the air pressure sensor.

7. The magnetic disk drive according to claim 4, characterized in that the preamplifier includes a through-hole communicating to the air pressure sensor.

8. The magnetic disk drive according to claim 4, characterized in that the preamplifier includes a groove for introducing an external air pressure to the air pressure sensor.

9. A preamplifier for a magnetic disk drive, wherein an air pressure sensor integrally formed with the preamplifier, the preamplifier being characterized by comprising a write driver for amplifying and supplying a recording signal to a magnetic recording element;

a read amplifier for inputting and amplifying a playback signal of a magnetic playback element;

a selector that inputs an output signal of the write driver, a playback signal of the magnetic playback element, and an output signal of the air pressure sensor and that selects and outputs any one of the input signals; and

an analog-digital converter that converts an analog signal to a digital signal and that outputs the digital signal.

10. The preamplifier for a magnetic disk drive, according to claim 9, characterized in that the air pressure sensor includes a lower electrode, a diaphragm including an upper electrode formed therein, and an isolated cavity between the lower electrode and the diaphragm.

11. A flexible printed cable assembly for a magnetic disk drive, the assembly being characterized by comprising a flexible printed cable including a terminal portion connected to wirelines to which lead wires of a magnetic recording element, a magnetic playback element, and a heater that are mounted in a magnetic head slider;

and a preamplifier wherein an air pressure sensor is integrally formed with the preamplifier, and a plane wherein the air pressure sensor of the preamplifier is formed is attached to the flexible printed cable.

12. The flexible printed cable assembly for a magnetic disk drive, according to claim 11, the assembly being characterized in that the flexible printed cable includes a through-hole in a portion opposite the air pressure sensor.

13. The flexible printed cable assembly for a magnetic disk drive, according to claim 11, the assembly being characterized in that the flexible printed cable includes a groove for introducing an external air pressure to the air pressure sensor.

14. The flexible printed cable assembly for a magnetic disk drive, according to claim 11, the assembly being characterized in that the air pressure sensor includes a lower electrode, a diaphragm including an upper electrode formed therein, and an isolated cavity between the lower electrode and the diaphragm.

15. The flexible printed cable assembly for a magnetic disk drive, according to claim 14, the assembly being characterized in that the preamplifier includes a through-hole communicating to the diaphragm of the air pressure sensor.

16. The flexible printed cable assembly for a magnetic disk drive, according to claim 14, the assembly being characterized in that the preamplifier includes a groove for introducing an external air pressure to the diaphragm of the air pressure sensor.

17. The flexible printed cable assembly for a magnetic disk drive, according to claim 11, the assembly being characterized by comprising a write driver for amplifying and supplying a recording signal to a magnetic recording element;

a read amplifier for inputting and amplifying a playback signal of a magnetic playback element;

a selector that inputs an output signal of the write driver, a playback signal of the magnetic playback element, and an output signal of the air pressure sensor and that selects and outputs any one of the input signals; and

an analog-digital converter that converts an analog signal to a digital signal and that outputs the digital signal.