Disclosed herein are methods of using embedded disconnected circuits (EDC) in magnetic storage media to assist in reading data from and writing data to the magnetic storage media. A wireless activation signal is used to activate an EDC in a magnetic storage media. Once activated, the EDC may assist to record data in and/or read data from one or more memory locations of the magnetic storage media.

A heat-assisted magnetic recording (HAMR) medium includes a perpendicular magnetic recording layer (typically a chemically-ordered FePt alloy), a seed/thermal barrier layer (typically MgO) below the recording layer, and a heat-sink layer with anisotropic thermal conductivity below the seed/thermal barrier layer. The in-plane thermal conductivity of the heat-sink layer is greater than its out-of-plane thermal conductivity. The heat-sink layer may be selected from hexagonal boron nitride (h-BN), hexagonal graphite, and the 6H polytype of hexagonal silicon carbide (6H-SiC). If the heat-sink layer is h-BN, the h-BN layer is formed on a seed layer and has its c-axis oriented out-of-plane (substantially orthogonal to the surface of the medium substrate).

A heat-assisted magnetic recording (HAMR) medium includes a perpendicular magnetic recording layer (typically a chemically-ordered FePt alloy), a seed/thermal barrier layer (typically MgO) below the recording layer, and a heat-sink layer with anisotropic thermal conductivity below the seed/thermal barrier layer. The in-plane thermal conductivity of the heat-sink layer is greater than its out-of-plane thermal conductivity. The heat-sink layer may be selected from hexagonal boron nitride (h-BN), hexagonal graphite, and the 6H polytype of hexagonal silicon carbide (6H-SiC). If the heat-sink layer is h-BN, the h-BN layer is formed on a seed layer and has its c-axis oriented out-of-plane (substantially orthogonal to the surface of the medium substrate).

The present disclosure provides a switch device. The switch device includes: a switch element, including a gate, a drain, a source, a back gate, a first body diode disposed between the drain and the back gate and a second body diode disposed between the source and the back gate; a first switch circuit, including a first switch connected between the back gate and an application end at ground potential; and a second switch circuit, including a second switch connected between the back gate and the source.

According to one embodiment, a magnetic disk device which supplies, at the time of startup of data write or startup of data read, electric power higher than steady electric power used to make, in advance, spacing between a magnetic disk and a magnetic head become saturated at a target value to a heater of the magnetic head for a specified time and, after an elapse of the specified time, gradually reduces the electric power to be supplied to the heater of the magnetic head to the steady electric power.

A suspension board with circuit including a first mounting region for mounting a slider and a second mounting region for mounting a piezoelectric element. The wiring circuit board includes a metal support layer, a base insulating layer, and a conductive layer. The conductive layer includes a first wiring pattern, a second wiring pattern, and a shield wiring pattern. The first wiring pattern includes a read wiring. The second wiring pattern includes a power supply wiring disposed at spaced intervals to the read wiring. The shield wiring pattern includes a shield wiring disposed between the read wiring and the power supply wiring.

The present disclosure discloses a magnetic head, a head gimbal assembly, a hard disk drive, and a method for processing a magnetic head. The method comprises irradiating at a fixed point proximal to the read/write part with a laser irradiation device until the read head and the write head are thermally expanded; orientating air bearing surfaces of a plurality of magnetic heads forming a magnetic strip toward a lapping surface of a lapping device after laser irradiation, holding the air bearing surfaces in place, lapping with the lapping device until the air bearing surfaces are coplanar; and disassembling the magnetic strip to obtain a lapped magnetic head. Through laser heating induced compensation, the heights of lapped read head and write head of the magnetic head meet their respective target values, ensuring the normal reading and writing of the storage medium of the magnetic disk.

The present disclosure discloses a magnetic head, a head gimbal assembly, a hard disk drive, and a method for processing a magnetic head. The method comprises irradiating at a fixed point proximal to the read/write part with a laser irradiation device until the read head and the write head are thermally expanded; orientating air bearing surfaces of a plurality of magnetic heads forming a magnetic strip toward a lapping surface of a lapping device after laser irradiation, holding the air bearing surfaces in place, lapping with the lapping device until the air bearing surfaces are coplanar; and disassembling the magnetic strip to obtain a lapped magnetic head. Through laser heating induced compensation, the heights of lapped read head and write head of the magnetic head meet their respective target values, ensuring the normal reading and writing of the storage medium of the magnetic disk.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The fourth magnetic layer includes a first element and at least one of Fe, Co or Ni. The first element including at least one selected from the group consisting of Cr, V, Mn, Ti, N and Sc. The fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.

A bond pad set includes at least one ground pad and at least one electrical bond pad configured to bias and send/receive signals. The bond pad set is electrically connected to a multiplicity of electrical components. At least one electrical bond pad of the bond pad set is shared between two or more of the electrical components.