Browse Prior Art Database

Overwrite of Servo Pattern in STW

IP.com Disclosure Number: IPCOM000123753D
Original Publication Date: 1999-Apr-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 1 page(s) / 42K

Publishing Venue

IBM

Related People

Ogasawara, K: AUTHOR [+3]

Abstract

This article describes an idea to make it possible to erase the embedded servo pattern written on the disk of HDD without using special equipment's . In the HDD , the coercive force of the Disk (Hc) is going up to increase the bit density in general. But this up trend is now becoming to limit the productivity of the embedded servo track write (STW) process in the HDD manufacturing(MFG). In the MFG process, Re-STW is one of the common operation to re-use or re-build the drives. This re-STW operation is o - Erase the all servo data pattern magnetically on the disk o - Re-Write the servo Pattern

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Overwrite of Servo Pattern in STW

   This article describes an idea to make it possible to
erase the embedded servo pattern written on the disk of HDD without
using special equipment's .  In the HDD , the coercive force of the
Disk (Hc) is going up to increase the bit density in general.  But
this up trend is now becoming to limit the productivity of the
embedded servo track write (STW) process in the HDD
manufacturing(MFG).  In the MFG process, Re-STW is one of the common
operation to re-use or re-build the drives.  This re-STW operation is
  o  - Erase the all servo data pattern magnetically on the disk
  o  - Re-Write the servo Pattern

   In order to erase the servo data on the disk, a special
equipment is used which generates a very strong magnetic field and
put HDD in  it and erase whole data pattern on the drive at one time.
This equipment is very useful, because the drive level erase is
possible and disassembling of the drive is not needed.  This is good
for the productivity of the re-STW process.  But recent High Hc trend
make it difficult to erase the disk on the other hand, at this
process the whole drive is exposed in the strong magnetic field, and
this can affect to the other magnetic components; such as VCM (voice
coil motor) magnet and Spindle motor magnets.  And the effect is
increasing as the Disk Hc is getting higher and applied field is
becoming higher.  The newly proposed idea solves this difficulty.
The new method does not erase the pre-w...