Sae Magnetics (h.k.) Limited

Chao-Hui Yang

Ellis T Cha

Yen Fu

Li-Yan Zhu

Qinghua Zeng

Xiaofeng Zhang

Yong Luo

Gautham Gowda

Mannuel Hernandez

Manny Hernandez

Gimbal designs are provided that minimize adverse dynamic performance of a HDD suspension, particularly subsequent to head-disk-interface (HDI) interactions. The improvement of operational performance can be seen in graphical representations of the vibrational modes of a gimbal mounted slider subsequent to such HDI interactions. Each gimbal design includes a ramp limiter formed as two separated arms connected by one or two transverse bars and a routing of conducting traces that relieves stress and minimally contacts these bars.

Gimbal mounted slider assembly with ramp limiter transverse bar

In a balanced head gimbal assembly for improved seeking performance, a slider having a magnetic head with a set of read elements to read data and a set of write elements to write data, an air-bearing surface, and a non-air-bearing surface is coupled to a suspension. The suspension includes a loadbeam, a flexure, and a balancing weight. The loadbeam is coupled to an actuator arm. The flexure, coupled to the loadbeam, has a window through which a dimple, coupled to the loadbeam, contacts a dimple contact point. The balancing weight, coupled to the flexure, has a configuration which permits alignment of a center of mass of the head gimbal assembly with the dimple contact point.

Method of reducing slider roll torque by balancing head gimbal assembly for improved seeking performance

Gimbal mounted slider assembly with transverse bars connecting inner edges of ramp limiter arms

A flexure with improved temperature sensitivity is disclosed. An embodiment of the present invention includes a bi-layered flexure that raises or lowers a read/write element a distance that is approximately equal to the distance of protrusion and retraction at varying temperatures.

Suspension with bi-layer flexure base whose layers have different coefficients of thermal expansion to eliminate thermally induced flying height variations

Balanced head gimbal assembly for improved seeking performance

An apparatus with a head gimbal assembly designed to reduce movement and rotation of components of the head gimbal assembly structure is disclosed. One embodiment head gimbal assembly may comprise a flexure including a ramp limiter, a suspension assembly further comprising a suspension tongue, a slider further comprising a magnetic head; and a load beam further comprising a lift tab; and a ramp further comprising a step to engage and support the ramp limiter and support and constrain the movement of the slider. In certain embodiments, the flexure may further comprise a flexure rail located at its end to reduce movement and rotation of the suspension tongue.

Suspension with locally strengthened gimbal

A loadbeam is locally stiffened by either, 1. the addition of strategically placed extra material to the loadbeam, 2. not removing material during the etching process to form the loadbeam, or 3. special forming, by crimping or bending, at specific sites on the beam. The use of local stiffening, when placed about the loadbeam dimple or between the dimple and flexure attachment points, with or without additional damping, can significantly improve the dynamical response of the loadbeam and eliminate vibrational modes of a slider mounted on the loadbeam during HDI interactions with disk surface asperities during disk drive operation.

Suspension with locally stiffened load beam

Suspension gimbal designs with better dynamic performances

In a system and method for a non-contact measurement of the fly height of a slider above a magnetic data storage medium using electrostatic force, a slider with a read/write head flies over a magnetic data storage medium. A series of distinct voltages are applied between the slider and the magnetic data storage medium, and corresponding read-back signals are recorded. Using the recorded read-back signals, coefficients for an empirical curve-fit equation are calculated. The coefficients are normalized and converted into a fly height measurement.

Non-contact measurement of slider fly height by electrostatic force

In a system and method for adjusting a static torque on a slider in a head-gimbal assembly, a substantially rigid mass is placed on an air-bearing surface (ABS) of a slider. A static attitude of the slider is measured, and an adjustment location and intensity for a flexure to yield a zero slider static attitude are calculated. The flexure is adjusted based on the measurement and calculations.

Adjustment of pitch and roll static torques in a disk drive head gimbal assembly

A flexure mounted slider and its method of fabrication is described, wherein the slider is affixed to a pair of highly compliant, transverse (to the longitudinal axis of a load beam) crossbars whose common axis passes directly above the center of percussion of the slider. The location of the center of percussion of the slider relative to the flexure eliminates translational motion of the slider during HDI events, but not twisting motion in a pitch direction during normal operation, and thereby minimizes the transfer of kinetic energy between the slider and the flexure during HDI events with a hard disk. The high compliance of the flexure crossbars to twists in a pitch direction, as well as the compliance of the outriggers to bending, allows the slider to pass over irregularities in the disk during normal operations.

Flexure for minimizing fly height modulation of near-contact recording sliders in a disk drive

An externally wireless laminated suspension for a hard disk drive are disclosed. In one embodiment, the externally wireless laminated suspension has an insulating layer to electrically isolate a first and second electrical trace from a conductive support layer. The second electrical trace crosses over the first electrical trace. The first electrical trace may be made of a first part on one side of the second electrical trace and a second part on the opposite side of the electrical trace. A conductive island area may be patterned into the support layer. The conductive island area may electrically couple the first part of the first electrical trace to the second part. The number of crossover points that the first electrical trace has may equal the number of crossover points that the second electrical trace has.

Method for providing electrical crossover in a laminated structure

A device is provided by which the stiffness coefficient of a flexure, in either a pitch or roll direction, can be measured while a slider is mounted thereon and while the flexure and slider are in a loaded condition as might be obtained during normal operational conditions of a HGA in a HDA. There are two methods of making the measurement, a static method in which the slider is loaded by an external weight called a pendulum and the angular displacement of the slider is measured, and a dynamical method in which the pendulum is caused to oscillate while in contact with the slider and its natural and loaded frequencies of oscillation are measured.

Self-loaded pendulum for slider flexure stiffness measurements

A system and method for testing the stroke and frequency response of a micro-actuator is disclosed. A dynamic parameter tester writes two concentric tracks on a noise free portion of a magnetic storage medium. A magnetic read/write head and a micro-actuator is positioned between the two concentric tracks. An initial oscillating voltage is applied at a first frequency to the micro-actuator while reading back a signal from the two concentric tracks. A stroke characteristic of the micro-actuator is calculated based in part on the read-back signal. The initial oscillating voltage is determined from previous tests. The first stroke characteristic of the micro-actuator is based on a time-averaged amplitude of the first signal. The two concentric tracks are written at a pre-determined pitch.

Growing community of inventors

Milpitas, CA, United States of America

Chao-Hui Yang