Load/unload technology for disk drives

Load/Unload (L/UL) is an alternative to contact start-stop (CSS) technology which eliminates stiction and wear failure modes associated with CSS. Other benefits of L/UL include increased areal density due to smooth disk surfaces, thinner overcoats and lower head flying height; improved shock resistance due to elimination of head slap; and reduced power consumption. Several mechanical design options exist for L/UL, and tolerance analysis plays a key role in height budgeting, interdisk spacing, and disk real estate usage. To prevent stiction failures arising from unintended landing of heads on stopped disks, a reliable actuator latch and power-off retract system are employed. A bidirectional inertia latch has better reliability than conventional inertia latch designs. A low voltage drop retract rectifier is required for reliable power-off retract in drives with supply voltages of 5 V or less.