DISKCON 2004

1. Suspension Design Progression for Increasing Shock PerformanceJacob BjorstromSr. Product Design Eng.Hutchinson TechnologySeptember 22, 2004 DISKCON 2004

2. Agenda • Shock Terminology • A Brief History of Mobile Shock Performance • Suspension/HGA Shock Design • Loadbeam, flexure, slider • Load/Unload Shock Design • Drive Design Impacts • Conclusions Hutchinson Technology Inc., September 22, 2004

3. Terminology Shock - a sudden disturbance induced on the hard drive G - measure of gravitational acceleration, the number of G’s is the magnitude of the shock event Pulse width - length of time that a G load is applied Op-Shock - a shock event applied while the drive is spinning with the slider on the disk Non-op Shock - a shock event where the slider is parked in it’s resting position, typically in a mobile drive this would be off the disk on the load/unload ramp. Gram - downwardforce supplied by the suspension to hold the slider on the disk G/gram - suspension parameter used to determine liftoff point of the slider from the disk, for a given gram load Hutchinson Technology Inc., September 22, 2004

4. 1995 1997 1999 2001 2003 2005 Mobile Timeline 17X Improvement in Suspension G/Gram 3.0” FF 41 G/gram 2.5” FF 61 G/gram 2.5” FF 83 G/gram 1.0” FF 160 G/gram 0.85” FF 394 G/gram 0.85” FF 707 G/gram Hutchinson Technology Inc., September 22, 2004

5. History of Requirements Hutchinson Technology Inc., September 22, 2004

6. 2. Magnetic Disks Recording Head Disk Drive 3. Actuator 4. Suspension 1. Drive Case Assembly Four Major Drive Components Affect Shock Performance Hutchinson Technology Inc., September 22, 2004

7. EFFECTIVE MASS BEND RADIUS ARM / MOUNT PLATE FLEXURE SLIDER LOADBEAM Redo with Mobile suspension Achieving Higher Shock • At the suspension level, the key is to reduce the effective load beam mass • Mass of the HGA past the bend radius • The further the mass is from the bend radius, the more detrimental it is to shock Hutchinson Technology Inc., September 22, 2004

8. Beam Design and Material Thickness • Thin railed beams have less massive cross-sections, which are ideal for shock Thick beam (101 mm) cross-section Thin railed beam (20 mm) cross-section Hutchinson Technology Inc., September 22, 2004

9. Mass Reduction • Best for shock with acceptable resonance • Allow for strategic mass reduction +14% Shock +5% B1 -5% T1 -9% Sway Hutchinson Technology Inc., September 22, 2004

10. Advanced Concept:Laminate Beams • Offers resonance improvement over thin beam designs while keeping high shock performance Hutchinson Technology Inc., September 22, 2004

11. 4.35 mm 9.3 mm Effective Beam Length • Effective beam length is the distance from the arm / swage plate edge to the load point • A shorter distance reduces suspension mass, and increases shock and resonance performance • Tradeoffs are space constraints and increased risk of gram load loss Hutchinson Technology Inc., September 22, 2004

12. Flexure Progression: Hub Clearance and Mass Past Present Future Hutchinson Technology Inc., September 22, 2004

13. Pico Femto Slider Size vs. G/Gram • The smaller the slider, the higher the G/gram for a given suspension • The G/gram delta between sliders increases as the slider becomes a larger portion of the effective mass Hutchinson Technology Inc., September 22, 2004

14. Pico Femto Slider Size vs. Total G’s • The smallest head is not necessarily the best for total HGA shock performance when accounting for gram load and slider negative air bearing pressure Hutchinson Technology Inc., September 22, 2004

15. Shrinking Form Factor • As the drive size decreases, the suspension becomes a large factor on drive level shock performance • Small form factor drives benefit from both increased suspension level G/gram and improved drive dynamics Hutchinson Technology Inc., September 22, 2004

16. Arm Suspension Gimbal & Slider Headlift Ramp Disk Non-op Shock Shock failure is caused by a large deflection of the head and gimbal during shock. Parameters that affect shock performance are: • Ramp design • Limiter design • Gimbal design Hutchinson Technology Inc., September 22, 2004

17. Motion Control: Limiters Limiters Suspension Slider Ramp Suspension Slider Ramp No limiters engaged (large deflection of slider and gimbal) Ramp and T-bar limiters engaged (slider and flexure motion restrained) Hutchinson Technology Inc., September 22, 2004

18. New Continuous Rail Form Headlift Standard Offset Form Headlift Headlifts • Parking the slider off the disk prevents shock damage • Mass reduction at the tip of the suspension provides the best results for increased G/gram liftoff • New headlift concepts offer twice the stiffness and half the mass Actual SEM Hutchinson Technology Inc., September 22, 2004

19. Results HTI leading edge micro-HDD suspension Mainstream micro-HDD suspension Shocked at: 1000 G’s 1 ms pulse No separation between disk and slider Large displacement and probable disk/head damage Hutchinson Technology Inc., September 22, 2004

20. Systems View • While the suspension is a large factor in drive shock performance, all components in the system must work together for optimal performance • The same suspension can have different shock performance in different drive designs Hutchinson Technology Inc., September 22, 2004

21. Conclusions • Shock has become a primary differentiator in mobile drive performance. • New HTI suspension designs continue to expand the current drive level shock performance envelope. • To maximize drive level shock performance, all components must be designed in harmony with one another. Hutchinson Technology Inc., September 22, 2004