Reed T. Hentges

Exploring Low Loss Suspension Interconnects for High Data Rates in Hard Disk Drives

For high data rate applications, current suspension interconnect solutions should stay above 50 Ohm differential impedance (Zdiff ) due to footprint limitations and frequency dependent ohmic losses of the stainless steel plane at low Zdiff . This paper describes the impedance and bandwidth (BW) design space of todays interconnects and also shows why this technology is still compatible with current system front-ends up to 3 Gb/s. Furthermore, the benefits of reduced power and higher overshoot using less than 50 Ohm impedance and high bandwidth interconnects are explored with a system model. Three alternate low impedance interconnect structures are used to demonstrate these benefits, and are explored analytically and evaluated for mechanical tradeoffs.