Laser Smoothing of the Load/Unload Tabs of Magnetic Recording Head Gimbal Assemblies

A novel technology to smooth the metal tab surfaces using a pulsed laser beam is applied to reduce the wear of the load/unload ramps used in disk drives that employ load/unload technology. The laser pulse length, pulse energy and the pulse repetition rate are so chosen that they cause the surface layer of the load/unload tab, approximately 2–3 um deep, to melt and refreeze quickly. As the surface layer melts, the surface tension of the melt removes most of the micro roughness and a smooth surface is obtained. The reduction in the micro surface roughness is confirmed by the AFM traces and a sharp decrease in the light scattered from the tab surface. In wear tests, such tabs show a remarkable improvement in the wear of the plastic load/unload ramps, allowing 5–10 × more load/unload cycles for a given amount of ramp wear.

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ELECTROSTATIC DISCHARGE EFFECT ON TMR RECORDING HEAD: A FLEX ON SUSPENSION CAPACITANCE APPROACH

International Journal of Modern Physics B ◽

10.1142/s0217979209063018 ◽

2009 ◽

Vol 23 (17) ◽

pp. 3586-3590 ◽

Cited By ~ 1

Author(s):

NUTTACHAI JUTONG ◽

APIRAT SIRITARATIWAT ◽

DUANGPORN SOMPONGSE ◽

PORNCHAI RAKPONGSIRI

Keyword(s):

Human Body ◽

Electrostatic Discharge ◽

Hard Disk Drives ◽

Electrical Characteristics ◽

Disk Drives ◽

Human Body Model ◽

Recording Head ◽

Body Model ◽

Recording Heads ◽

First Time

Electrostatic discharge (ESD) effects on GMR recording heads have been reported as the major cause of head failure. Since the information density in hard-disk drives has dramatically increased, the GMR head will be no longer in use. The tunneling magnetoresistive (TMR) read heads are initially introduced for a 100 Gbit/in2 density or more. Though the failure mechanism of ESD in GMR recording heads has not been explicitly understood in detail, a study to protect from this effect has to be done. As the TMR head has been commercially started, the ESD effect must be considered. This is the first time that the TMR equivalent circuit has been reported in order to evaluate the ESD effect. A standard human body model (HBM) is discharged across R+ and R- where the capacitances of flex on suspension (FOS) are varied. It is intriguingly found that the electrical characteristics of the TMR head during the discharge period depend on the discharge position. This may be explained in terms of the asymmetry impedance of TMR by using adapted Thevenin's theory. The effect of FOS components on TMR recording heads is also discussed.

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Explosive decomposition of slightly compacted powders of lead azide over a wide range of laser pulse length

Combustion Explosion and Shock Waves ◽

10.1007/s10573-008-0088-8 ◽

2008 ◽

Vol 44 (5) ◽

pp. 583-585 ◽

Cited By ~ 1

Author(s):

V. V. Medvedev

Keyword(s):

Laser Pulse ◽

Pulse Length ◽

Lead Azide ◽

Explosive Decomposition ◽

Wide Range ◽

Laser Pulse Length

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Crystallization Studies of Glassy Te-Se-Br Thin Films

MRS Proceedings ◽

10.1557/proc-172-221 ◽

1989 ◽

Vol 172 ◽

Author(s):

J. L. Adam ◽

C. Ortiz ◽

J. R. Salem ◽

X. H. Zhang

Keyword(s):

Thin Films ◽

Heat Flow ◽

Laser Power ◽

Network Formation ◽

Laser Energy ◽

Pulse Length ◽

Three Dimensional ◽

Complete Loss ◽

Fractal Network ◽

Laser Pulse Length

AbstractWe have studied the effect of laser irradiation on Te-Se-Br thin films. The major effects were found to be dominated by changes in composition because of the complete loss of Br and variable loss of Se. These losses are measured by EIDS and are reasonable in view of the temperatures obtained from a heat flow calculation. The remaining Te-Se material can be made crystalline under specific conditions of laser pulse length and laser power (which determine the cooling rate). We have been able to establish that the crystallization starts with surface filamentary growth exhibiting fractal network formation. With higher laser energy it tends to coalesce to form three dimensional crystals.

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Friction and Wear Reduction of 440C Stainless Steel by Ion Implantation

MRS Proceedings ◽

10.1557/proc-27-661 ◽

1983 ◽

Vol 27 ◽

Cited By ~ 10

Author(s):

L. E. Pope ◽

F. G. Yost ◽

D. M. Follstaedt ◽

S.T. Picraux ◽

J. A. Knapp

Keyword(s):

Stainless Steel ◽

Surface Layer ◽

Yield Strength ◽

Ion Implantation ◽

Friction And Wear ◽

No Reduction ◽

Wear Reduction ◽

Amorphous Surface ◽

Wear Tests ◽

Friction And Wear Tests

ABSTRACTFriction and wear tests on ion-implanted 440C stainless steel discs have been extended to high Hertzian stresses (≤ 3150 MPa). Implantation of 2 × 1015 Ti/mm2 (180–90 keV) and 2 × 1015 C/mm2 (30 keV) into 440C reduces friction (∼40%) and wear (> 80%) for Hertzian stresses as large as 2900 MPa, stresses which significantly exceed the yield strength of 440C (∼1840 MPa). Implantation of 4 × 1015 N/mm2 (50 keV) into 440C reduces friction slightly (∼25%) for Hertzian stresses > 1840 MPa but provides little or no reduction in wear. The amount of Ti remaining in the wear tracks correlates with the reductions in friction and wear. The implantation of Ti and C produces an amorphous surface layer which is believed to reduce friction and wear, whereas N implantation is expected to produce hard nitride particles which probably do not modify the hardness of 440C (KHN = 789) significantly.

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Laser Pulse Triggering of the Explosive Crystallization in Amorphous Si and Ge Thin Films

MRS Proceedings ◽

10.1557/proc-157-449 ◽

1989 ◽

Vol 157 ◽

Cited By ~ 2

Author(s):

W. Marine ◽

J. Marfaing

Keyword(s):

Thin Films ◽

Melting Point ◽

Laser Pulse ◽

Pulse Length ◽

Electronic Microscopy ◽

Explosive Crystallization ◽

Amorphous Si ◽

Laser Pulse Length ◽

Electronic Microscope

ABSTRACTThe structure and morphologies of the thin amorphous a-Si and oc-Ge films crystallized “in situ” in an electronic microscope by pulsed YAG laser have been studied using conventional and high-resolution transmission electronic microscopy observations. It is found that the laser induced nucleation rate (I) is laser pulse length dependent. I is about 1021-1022 cm−3 s−1 (α-Si) and 1023-1025 cm−3 s−1 (α-Ge) near the melting point. Explosive dendritic formation is the result of competition between solid state light induced nucleation and melting mediated explosive growth.

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Laser-Induced Multi-Crystallization of Thin Germanium Films

MRS Proceedings ◽

10.1557/proc-129-455 ◽

1988 ◽

Vol 129 ◽

Author(s):

C. Ortiz ◽

K.A. Rubin ◽

S. A. Iuria

Keyword(s):

Pulse Length ◽

Laser Pulses ◽

Beam Diameter ◽

Amorphous Films ◽

Small Spot ◽

Laser Beam Irradiation ◽

Crystalline Films ◽

Kinetics Of ◽

Deposited Films ◽

Laser Pulse Length

ABSTRACTWe report here the crystallization kinetics of thin (35nm and 60nm) amorphous as-deposited Ge filins using diffraction limited laser beam irradiation and laser pulses between 30ns and IreS. The recrystallization of crystalline as-deposited films was also studied for similar laser conditions. Crystallization was observed for pulses as short as 50ns. We conclude that the use of small beam spots (-1μm) gives a very different crystallization morphology from that observed previously for larger beam diameter and same laser pulse length. In our case for short irradiation times, the nucleation process dominates over crystal growth. Laser irradiation of as-deposited crystalline films produced grains with significantly less defects than grains crystallized from as-deposited amorphous films. Temperature calculations allow us to understand these results by showing that only the small spot irradiation sustains the material at high temperature for times comparable to the pulse width.

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