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U of M Material Science Seagate Design Group

Alan Bagwell

Tony Lindert

Loc Nguyen

Greg Rayner

Industrial Mentor:Dr. Vince Engelkes

Faculty Advisor:Prof. C. Daniel Frisbie

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Outline

Company Overview

Recording Technology

Reader and Writer Elements

Design Project

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Seagate

• Founded in 1979 by Alan Shugart and Finis Conner in Scotts Valley, California.

• Public company in 1981 (NASDAQ: SGAT). • Now traded under NASDAQ: SXT

• World’s leading provider of hard disc drives.– Approximately 54,000 employees in 28 worldwide locations. – Highest market share of hard drive sales; 33% of overall market.– FY2008: 182M drives shipped; revenue of $12.7B

• Shipped billionth drive April 2008• January 5, 2009 – 3.5-inch 7200-RPM drive with an areal

density of 329 Gigabits per square inch.

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Seagate’s Global Presence

Fremont, Milpitas, Santa Clara, Scotts Valley, Sunnyvale, CA

Oklahoma City, OK

Ang Mo Kio, Science Park & Woodlands, Singapore

Bangkok & Korat, Thailand

Minneapolis, MN

Penang, Malaysia

Wuxi, China

Longmont, CO

Springtown, N. Ireland

Shrewsbury, MA

Paris, France

Drives and Components

Regional HQ’s and Sales

Shanghai, China

Tokyo, JapanBeijing, China

Delhi, India Suzhou, China

Taiwan

Design

Customer Support

Amsterdam, Netherlands

Seagate Services Headquarters

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Seagate in Minnesota

Recording Heads OperationSeagate’s internal and principal supplier of recording heads.

BLOOMINGTON, MN

SHAKOPEE, MN

Enterprise Drive DivisionDevelops the largest, fastest and most advanced enterprise disc drives in the world.

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R&D Investment (2008)

361

971

0

250

500

750

1000

Seagate Competitors

WDC

STX

$ Millions

Source: Seagate Market & Competitive Intelligence

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Market Share EstimatesTotal Market

Source: Seagate Market & Competitive Intelligence

WDC26%

TOSH9%

HGST16%

FUJ8%

STX32%

SMG9%

Q4 FY08 132.3M Units

WDC27%

TOSH8%

HGST17%

FUJ7%

STX33%

SMG8%

Q3 FY08 132.3M Units

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Hard Drive Overview

• Platters store data in magnetically oriented grains

• Actuator arm moves the head closer or farther from the platter center

• Head contains reader/writer elements

• Platter spins at up to 15,000 RPM

• Logic board controls motion of actuator

http://en.wikipedia.org/wiki/File:Hard_drive-en.svg

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Platter Construction• Aluminum or glass/ceramic

with metal sputter• Concentric circles divide it into

tracks/cylinders (10,000+)• Radial lines divide it into

sectors (often 63)• Tracks and sectors intersect

to form blocks: typically 512 bytes per block

http://en.wikipedia.org/wiki/File:MagneticMedia.png

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Total Data Capacity

• Data = Heads * Cylinders * Sectors * Bytes

• Amount of platters can be increased

• Data density ultimately comes down to how small the bits can be made before they become unreadable

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Improving Data Density

• Platter materials – thermal considerations– Perpendicular recording (2005) – Giant magnetoresistance (Nobel Prize 2007)

• Actuator head sensitivity

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Actuator Head (“Slider”)

• Actuator head contains read/write elements• Key to increasing data storage density

http://www.pctechguide.com/31HardDisk_Construction.htm

http://www.pctechguide.com/31HardDisk_Construction.htm

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Challenges for the Slider

• Reader element must be made more sensitive in order to read smaller and more densely packed bits.

• Writer, in turn, must be made stronger to compensate for smaller size in order to write smaller bits.

• “Fly height” must be minimized to reduce error

Vince Engelkes, Seagate

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Flying Height

• Flying heights of 10 nm currently achieved (equivalent to 30 average sized atoms).

• If the slider is too close to the surface, surface roughness leads to a decrease in reliability and product life.

• Increasing the flying height leads to performance error.

• Slider held above the disk surface by “Air Bearing”

Air bearing

Suspension

Slider

Vince Engelkes, Seagate

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Fly Height Control

Adaptive Clearance Control•Integrated heating element added to transducer.•In-drive algorithms adjust clearance between the reader/writer elements and disc.

Dr Marcus Mooney, Materials for Electronics, Seagate

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Wafer Process

Wafer Fabrication • Creation of electromagnet uses many processes

• Photolithography• Electro-plating• Vacuum deposition• Vacuum milling• Chemical-Mechanical Polishing (CMP)• Wet etching• Metrology, Inspection & Electrical Test

Magnetic Recording Heads

• Creating a wafer (a group of heads) takes about 700 different manufacturing steps

• 80,000+ recording heads are built on a 200mm wafer

Wafer

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Slider Construction

• Aside from reader/writer fabrication, careful processing of the air bearing components of the slider is essential.

• Air bearings are designed to control the fly height, pitch, roll, head-media spacing, and many other important specifications of the slider.

• Techniques such as ion milling and photolithography are used

Dr Marcus Mooney, Materials for Electronics, Seagate

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Head Materials

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Design Project

• Increase areal density and product life.– Market Need

• More storage space• Reliability• Cheap

– Project Need• Roughness and positioning precision of 2A (currently ~10A).• Possible materials change

– Should not undergo phase changes up to ~250C.– Should not be react with neighboring materials– Similar or better properties

• Reliable: 5+ years of warranties.• Ease of production/fabrication• Cost consideration

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Q&A