# US 7,609,473 B1 · Dissipation of liquid droplets in a magnetic disk drive > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,473 B1 - Document ID: US7609473B1 - Status: Granted - Kind: B1 - Application number: 12/120,171 - Filed: 2008-05-13 - Published: 2009-11-19 - Granted: 2009-10-27 - Earliest claimed: 2008-05-13 - Assignees: Hitachi Global Storage Technologies Netherlands B.V. - Inventors: Charles M. Mate - Web page: https://patentgrep.com/patent/US7609473B1 ## CPC - G11B 19/041: {Detection or prevention of read or write errors} - G11B 25/043: {using rotating discs} - G11B 33/1453: {by moisture} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract Magnetic disk drives and associated methods are described for an improved process for dissipating liquid droplets that may accumulate on a slider of the magnetic disk drive. For the droplet removal process, the slider having the liquid droplet is unloaded from the magnetic disk. For example, the slider may be unloaded from the magnetic disk and onto a ramp assembly. While unloaded from the magnetic disk, a heating power is applied to a TFC heating element in the slider to increase the temperature of the slider. The temperature is increased to a threshold temperature which dissipates any liquid droplets that may have accumulated on the slider. After the liquid droplets have dissipated, the slider may again be loaded onto the magnetic disk. ## Claims ### Claim 1 A magnetic disk drive operable to perform a droplet removal process to dissipate liquid droplets formed on a slider during operation, the magnetic disk drive comprising: a magnetic disk; a slider having a read/write head operable to read data from and write data to the magnetic disk, wherein the slider includes a Thermal Fly-height Control (TFC) heating element operable to cause a protrusion of a read/write head toward the magnetic disk; and a control system operable to unload the slider from the magnetic disk to initiate the droplet removal process, to apply a heating power to the TFC heating element in the slider to heat the slider to a threshold temperature to dissipate a liquid droplet, and to load the slider back onto the magnetic disk. ### Claim 2 (depends on 1) The magnetic disk drive of claim 1 further comprising a ramp assembly operable to receive an actuator/suspension arm that is supporting the slider when the slider is unloaded from the magnetic disk. ### Claim 3 (depends on 1) The magnetic disk drive of claim 1 wherein the control system is further operable to perform the droplet removal process upon power up of the magnetic disk drive. ### Claim 4 (depends on 1) The magnetic disk drive of claim 1 wherein the control system is further operable to perform the droplet removal process periodically based on threshold time periods. ### Claim 5 (depends on 1) The magnetic disk drive of claim 1 wherein the control system is further operable to perform the droplet removal process responsive to detecting the liquid droplet of a threshold size having formed on the slider. ### Claim 6 (depends on 1) The magnetic disk drive of claim 1 wherein the control system is further operable to apply the heating power to the TFC heating element which is in the range of approximately 100% to 120% of the normal operating power applied to the TFC heating element. ### Claim 7 (depends on 1) The magnetic disk drive of claim 1 wherein the control system is further operable to apply the heating power to the TFC heating element for a threshold time period depending on the composition of the liquid droplet. ### Claim 8 A control system of a magnetic disk drive that is operable to perform a droplet removal process to dissipate liquid droplets formed on a slider during operation of the magnetic disk drive, the control system comprising: a droplet removal process (DRP) controller operable to instruct a motor controller to unload the slider from a magnetic disk in the magnetic disk drive to initiate the droplet removal process; the DRP controller further operable to instruct a TFC controller to apply a heating power to a Thermal Fly-height Control (TFC) heating element in the slider to heat the slider to a threshold temperature to dissipate the liquid droplet; the DRP controller further operable to instruct the motor controller to load the slider back onto the magnetic disk. ### Claim 9 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to instruct the motor controller to unload the slider from the magnetic disk and onto a ramp assembly in the magnetic disk drive. ### Claim 10 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to perform the droplet removal process upon power up of the magnetic disk drive. ### Claim 11 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to perform the droplet removal process periodically based on threshold time periods. ### Claim 12 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to perform the droplet removal process responsive to detecting the liquid droplet of a threshold size having formed on the slider. ### Claim 13 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to instruct the TFC controller to apply the heating power to the TFC heating element which is in the range of approximately 100% to 120% of the normal operating power applied to the TFC heating element. ### Claim 14 (depends on 8) The control system of claim 8 wherein the DRP controller is further operable to instruct the TFC controller to apply the heating power to the TFC heating element for a threshold time period depending on the composition of the liquid droplet. ### Claim 15 A method of performing a droplet removal process in a magnetic disk drive to dissipate liquid droplets formed on a slider during operation, the method comprising: unloading the slider from a magnetic disk in the magnetic disk drive to initiate the droplet removal process; applying a heating power to a Thermal Fly-height Control (TFC) heating element in the slider to heat the slider to a threshold temperature to dissipate a liquid droplet; and loading the slider back onto the magnetic disk. ### Claim 16 (depends on 15) The method of claim 15 wherein unloading the slider from a magnetic disk comprises: unloading the slider from the magnetic disk and onto a ramp assembly in the magnetic disk drive. ### Claim 17 (depends on 15) The method of claim 15 wherein the droplet removal process is performed upon power up of the magnetic disk drive. ### Claim 18 (depends on 15) The method of claim 15 wherein the droplet removal process is performed periodically based on threshold time periods. ### Claim 19 (depends on 15) The method of claim 15 wherein the droplet removal process is performed responsive to detecting the liquid droplet of a threshold size having formed on the slider. ### Claim 20 (depends on 15) The method of claim 15 wherein applying a heating power to a TFC heating element in the slider comprises: applying the heating power to the TFC heating element which is in the range of approximately 100% to 120% of the normal operating power applied to the TFC heating element. ### Claim 21 (depends on 15) The method of claim 15 wherein applying a heating power to a TFC heating element in the slider comprises: applying the heating power to the TFC heating element for a threshold time period depending on the composition of the liquid droplet. ### Claim 22 A magnetic disk drive operable to perform a droplet removal process to dissipate liquid droplets formed on a slider during operation, the magnetic disk drive comprising: a magnetic disk; a slider having a read/write head operable to read data from and write data to the magnetic disk, wherein the slider includes a Thermal Fly-height Control (TFC) heating element operable to cause a protrusion of a read/write head toward the magnetic disk; a ramp assembly; and a control system operable to unload the slider from the magnetic disk and onto the ramp assembly to initiate the droplet removal process, to apply a heating power to the TFC heating element in the slider for a threshold time period to heat the slider to a threshold temperature to dissipate a liquid droplet, and to load the slider from the ramp assembly onto the magnetic disk. ### Claim 23 (depends on 22) The magnetic disk drive of claim 22 wherein the control system is further operable to perform the droplet removal process upon power up of the magnetic disk drive. ### Claim 24 (depends on 22) The magnetic disk drive of claim 22 wherein the control system is further operable to perform the droplet removal process periodically based on threshold time periods. ### Claim 25 (depends on 22) The magnetic disk drive of claim 22 wherein the control system is further operable to perform the droplet removal process responsive to detecting the liquid droplet of a threshold size having formed on the slider.