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

Outline Company Overview Recording Technology Reader and Writer Elements Design Project

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.

Seagate’s Global Presence Springtown, N. Ireland Minneapolis, MN Fremont, Milpitas, Santa Clara, Scotts Valley, Sunnyvale, CA Amsterdam, Netherlands Paris, France Beijing, China Tokyo, Japan Shrewsbury, MA Wuxi, China Suzhou, China Delhi, India Shanghai, China Oklahoma City, OK Bangkok & Korat, Thailand Taiwan Longmont, CO Penang, Malaysia Ang Mo Kio, Science Park & Woodlands, Singapore Drives and Components Regional HQ’s and Sales Design Customer Support Seagate Services Headquarters Seagate Confidential 4

Seagate in Minnesota Recording Heads Operation Seagate’s internal and principal supplier of recording heads. BLOOMINGTON, MN Enterprise Drive Division Develops the largest, fastest and most advanced enterprise disc drives in the world. SHAKOPEE, MN Seagate Confidential 5 5

R&D Investment (2008) $ Millions Source: Seagate Market & Competitive Intelligence

Market Share Estimates Total Market Q3 FY08 132.3M Units Q4 FY08 132.3M Units Source: Seagate Market & Competitive Intelligence Seagate Confidential 7

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

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

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

Improving Data Density Platter materials – thermal considerations Perpendicular recording (2005) Giant magnetoresistance (Nobel Prize 2007) Actuator head sensitivity

Actuator Head (“Slider”) http://www.pctechguide.com/31HardDisk_Construction.htm Actuator head contains read/write elements Key to increasing data storage density http://www.pctechguide.com/31HardDisk_Construction.htm

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

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” Suspension Slider Air bearing Vince Engelkes, Seagate

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

Wafer Process Wafer Magnetic Recording Heads Wafer Fabrication Creating a wafer (a group of heads) takes about 700 different manufacturing steps 80,000+ recording heads are built on a 200mm wafer Wafer 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

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

Head Materials

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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