Browse Prior Art Database

Combination of glide height tester or accoustic emission tester and AFM

IP.com Disclosure Number: IPCOM000014274D
Original Publication Date: 1999-Dec-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Frank Krausel: AUTHOR [+4]

Abstract

This article describes a combination of a Glide Hight Tester (GHT) or Accoustic Emission Tester (AET) and an Atomic Force Microscope (AFM) for detecting the topography of defects on magnetic disks. Current procedures require at least two devices to locate a defect position on a disk, to mark it and to characterize it. In transferring the disks from the first device on which the detection of the defect was made to the second device which carries out the actual characterization, the disk must be removed from the spindle. In doing so, the reference points of the spindle coordinate system are lost. German Patent Application 198 11 347.1 describes a combination of a MAG tester (magnetic tester, spin tester) and AFM/MFM which is able to directly and quickly detect and characterize sub-micrometer defects on the surface of magnetic disks.

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Combination of glide height tester or accoustic emission tester and AFM

This article describes a combination of a Glide Hight Tester (GHT) or Accoustic Emission Tester (AET) and an Atomic Force Microscope (AFM) for detecting the topography of defects on magnetic disks.

Current procedures require at least two devices to locate a defect position on a disk, to mark it and to characterize it.

In transferring the disks from the first device on which the detection of the defect was made to the second device which carries out the actual characterization, the disk must be removed from the spindle. In doing so, the reference points of the spindle coordinate system are lost.

German Patent Application 198 11 347.1 describes a combination of a MAG tester (magnetic tester, spin tester) and AFM/MFM which is able to directly and quickly detect and characterize sub-micrometer defects on the surface of magnetic disks.

When using a GHT, a specific measuring head flies over the rotating thin film disk. The head is not able either to read or to write. However, in case it strikes an elevation on the surface of the disk, a piezoelectric signal is generated due to the motion of the head. The information that can be gathered essentially relates to the hight of the elevation; the lateral extension can, however relatively inaccurate, be estimated from the duration and the vibration form. Furthermore, the GHT allows for the generation of a defect map.

For determining the position of the elevation the radius R
(i.e., the distance from the spindle center) and the angle I (i...