Patent · US Expired

Master magnetic information carrier, fabrication method thereof, and a method for manufacturing a magnetic recording medium

US6613459B1 · kind B1 · utility

22Cited by
7References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 17, 2000
Grant dateSep 2, 2003
Priority date
Expiry dateMar 13, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B5/82
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A master magnetic information carrier has embedded magnetic films that are free from protrusion and recess. The master disk is fabricated by the steps of laminating Co-based soft magnetic film on a resin base plate, forming isolated magnetic films in predetermined region by patterning the magnetic film, pressing a die from above the isolated magnetic films while heating the base plate with the magnetic films thereon, and releasing the die. Since the master disk is a mold product fabricated by pressing the die, the embedded magnetic films and the resin surface portion surrounding the magnetic films are intimately adjoined and protrusions and recesses at the boundary between them are suppressed to a minimum. The surface of the master disk is so smooth and flat that generation of flaws and gouges on the magnetic recording medium and transfer of particles and chemical contaminants to the recording medium in the contact duplication process are reduced.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.