A discrete track thin film magnetic record disk and a method of making it

• Main Authors: KROUNBI, MOHAMAD TOWFIK, SANDERS, IAN LEWIS, PATLACH, ALVIN MURRAY
• Format: Patent
• Language: English; French; German
• Published: 02.11.1989
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

A discrete track thin film magnetic metal or oxide record disk is made by forming a thin film (12) of magnetic material on a substrate (10), patterning the magnetic film with a chemically etchable support layer (14) and a high resolution photoresist layer (16), removing portions of the magnetic film and refilling with nonmagnetic material to form concentric nonmagnetic guard bands (32), and then applying a top layer (33) of additional nonmagnetic material as a passivating and protective disk overcoat after removal of the remaining support layer and photoresist. The exposed photoresist and portions of the chemically etchable support layer beneath the side walls of the patterned photoresist defining the edges of the magnetic tracks are removed in a photoresist developer which also creates undercuts in the support layer beneath the side walls. The undercuts prevent "fences" and provide smooth interfaces between the magnetic tracks and the nonmagnetic guard bands. In one embodiment of the disk, a continuous layer of nonmagnetic material serves as both the guard bands and the protective overcoat and has a height in the guard band regions greater than the height of the adjacent magnetic tracks so as to prevent damage to the magnetic tracks in the event the magnetic tracks are contacted by a slider supporting a read/write head.