Methodology for the determination of the minimum and gap flying height of a thin-film slider

A method for measuring a height of an air bearing between a recording head and a rotating disk, wherein the recording head has a read/write element located within a trailing edge that extends from an interface of a head substrate, the trailing edge has an outer tip and an air bearing surface that is recessed from an air bearing surface of the head substrate, comprising the steps of:

• a) measuring an index of refraction n and an extinction coefficient k for the head substrate and the trailing edge;
• a) rotating the disk so that the interface of the head substrate is separated from the disk by an air bearing height h.sub.i, the read/write element is separated from the disk by an air bearing height h.sub.g, and the trailing edge outer tip is separated from the disk by an air bearing height h.sub.m ;
• b) measuring the heights h.sub.i, h.sub.g and h.sub.m using the index of refraction n and extinction coefficient k of the head substrate and trailing edge;
• c) measuring a plurality of profile data of the head substrate and the trailing edge;
• d) measuring an air bearing height h.sub.1 on the recording head;
• e) varying the profile data so that a corresponding point is equal to the height h.sub.1 ;
• and,
• f) comparing the measured heights h.sub.g and h.sub.m with corresponding points of the varied profile data to determine an error.

A method for verifying a measured height of an air bearing of a recording head which has a read/write element located within a trailing edge that extends from an interface of a head substrate, the trailing edge has an outer tip and an air bearing surface that is recessed from an air bearing surface of the head substrate, wherein the head substrate is separated from a rotating disk by an air bearing height h.sub.i, the read/write element is separated from the disk by an air bearing height h.sub.g, and the trailing edge outer tip is separated from the disk by an air bearing height h.sub.m, comprising the steps of:

• a) measuring a profile of the head substrate and the trailing edge;
• b) measuring an air bearing height h.sub.1 on the recording head;
• c) varying the profile data so that a corresponding point of the profile data is equal to the height h.sub.1 ;
• and;
• d) comparing the measured heights h.sub.g and h.sub.m with corresponding points of said varied profile data to determine an error.

A system for measuring a height of an air bearing between a recording head and a rotating disk, wherein the recording head has a read/write element located within a trailing edge that extends from an interface of a head substrate, the trailing edge has an outer tip and an air bearing surface that is recessed from an air bearing surface of the head substrate, comprising:

• a disk that rotates adjacent to the recording head such that the interface of the head substrate is separated from the disk by an air bearing height h.sub.i, the read/write element is separated from the disk by an air bearing height hg, and the trailing edge outer tip is separated from the disk by an air bearing height h.sub.m ;
• a light source that directs a light beam through the disk so that the light beam is reflected from the recording head;
• a photodetector that detects the reflected light beam;
• a mechanism that moves the light beam relative to the recording head so that the light beam is reflected from the interface of the head substrate, the read/write element, and the trailing edge outer tip;
• and,
• a computer which calculates the heights h.sub.i, h.sub.g and h.sub.m from the reflected light beam.