摘要:
By subdividing the free layer of a GMR/TMR device into multiple sub-elements that share common top and bottom electrodes, a magnetic detector is produced that is domain stable in the presence of large stray fields, thereby eliminating the need for longitudinal bias magnets. Said detector may be used to measure electric currents without being affected by local temperature fluctuations and/or stray fields.
摘要:
A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
摘要:
Method and apparatus are presented for electrically coupling a slider to ground. In one embodiment, a bonding pad is provided on a side of the slider body separate from the bonding pad(s) used for read/write signals. This separate bonding pad is electrically coupled within the slider body to components that are to be coupled to ground. A separate conductor provided on the suspension (e.g., a trace, a flex circuit, etc.) may be electrically coupled to the separate bonding pad via gold ball bonding. The conductor is also coupled to ground in the hard-disk drive device (e.g., via the preamplifier). The use of the separated bonding pad and trace may negate the need to use a conductive adhesive to electrically ground the slider via its attachment to the tongue of a slider.
摘要:
A slider mounted TAMR (Thermal Assisted Magnetic Recording), DFH (Dynamic Flying Height) type read/write head using optical-laser generated surface plasmons in a small antenna to locally heat a magnetic medium, uses the same optical laser at low power to pre-heat the antenna. Maintaining the antenna at this pre-heated temperature, approximately 50% of its highest temperature during write operations, allows the DFH mechanism sufficient time to compensate for the thermal protrusion of the antenna at that lower temperature, so that thermal protrusion transients are significantly reduced when a writing operation occurs and full laser power is applied. The time constant for antenna protrusion is less than the time constant for DFH fly height compensation, so, without pre-heating, the thermal protrusion of the antenna due to absorption of optical radiation cannot be compensated by the DFH effect.
摘要:
A spin-torque MRAM array has MRAM cells arranged in rows and columns. Bit lines are connected to each of the MRAM cells on each column. Source select lines are connected to each MRAM cell of a pair of rows and are oriented orthogonally to the bit lines. Write lines are connected to the gate of the gating MOS transistor of each MRAM cell of the rows. The MRAM cells are written in a two step process with selected MRAM cells written to a first logic level (0) in a first step and selected MRAM cells written to a second logic level (1) in a second step. A second embodiment of the spin-torque MRAM array has the bit lines commonly connected together to receive the data and the source select lines commonly connected together to receive an inverse of the data for writing.
摘要:
A magnetic field angle sensor for measurement of a magnetic field angle over a 360° range has magnetic tunnel junction elements oriented at multiple angles. The magnetic field angle sensor includes multiple magnetic tunnel junction elements formed on a substrate that have an anti-ferromagnetic layer and pinned synthetic multiple layer. The magnetic tunnel junction elements are patterned to have a large dimensional aspect ratio and large anisotropies the pinned synthetic multiple layer of the magnetic tunnel junction elements. The magnetic tunnel junction elements are annealed in the presence of a strong magnetic field in a direction of the reference axis and the annealed for a second time with no external magnetic field so that exchange pinning is reduced and strong stress induced anisotropies of the pinned synthetic multiple layer align magnetization of the pinned synthetic multiple layer align a long axis of each of the magnetic tunnel junction elements.
摘要:
By subdividing the free layer of a GMR/TMR device into multiple sub-elements that share common top and bottom electrodes, a magnetic detector is produced that is domain stable in the presence of large stray fields, thereby eliminating the need for longitudinal bias magnets. Said detector may be used to measure electric currents without being affected by local temperature fluctuations and/or stray fields.
摘要:
A second shield layer, under the master shielding layer, is added to a segmented MRAM array. This additional shielding is patterned so as to provide one shield per bit slice. The placement of longitudinal biasing tabs at the ends of these segmented shields ensures that each segmented shield is a single magnetic domain, making it highly effective as a shield against very small stray fields.
摘要:
A magnetic field angle sensor for measurement of a magnetic field angle over a 360° range has magnetic tunnel junction elements oriented at multiple angles. The magnetic field angle sensor includes multiple magnetic tunnel junction elements formed on a substrate that have an anti-ferromagnetic layer and pinned synthetic multiple layer. The magnetic tunnel junction elements are patterned to have a large dimensional aspect ratio and large anisotropies the pinned synthetic multiple layer of the magnetic tunnel junction elements. The magnetic tunnel junction elements are annealed in the presence of a strong magnetic field in a direction of the reference axis and the annealed for a second time with no external magnetic field so that exchange pinning is reduced and strong stress induced anisotropies of the pinned synthetic multiple layer align magnetization of the pinned synthetic multiple layer align a long axis of each of the magnetic tunnel junction elements.
摘要:
An MRAM reference cell sub-array provides a mid-point reference current to sense amplifiers. The MRAM reference cell sub-array has MRAM cells arranged in rows and columns. Bit lines are associated with each column of the sub-array. A coupling connects the bit lines of pairs of the columns together at a location proximally to the sense amplifiers. The MRAM cells of a first of the pair of columns are programmed to a first magneto-resistive state and the MRAM cells of a second of the pair of columns are programmed to a second magneto-resistive state. When one row of data MRAM cells is selected for reading, a row of paired MRAM reference cells are placed in parallel to generate the mid-point reference current for sensing. The MRAM reference sub-array may be programmed electrically or aided by a magnetic field. A method for verifying programming of the MRAM reference sub-array is discussed.