摘要:
A direct access storage device (DASD) employs head-specific off-track read capability (OTRC) in data access operations. A method of operation of the DASD involves providing within the DASD a rotating data storage medium and one or more read heads positionable for interaction with the data storage medium. The OTRC particular to each read head is determined and then applied in accessing data from the data storage medium. One manner of applying the OTRC to access data is to use the OTRC in scheduling random queued seeks. The OTRC for a head is referenced within buffer memory and applied to determine which target data can be accessed most quickly. The seeks are scheduled accordingly. A single table with a nominal seek time can be used for all heads, with a custom adder being added for each particular head. The OTRC can also be applied to alter the seek algorithm. That is, a given seek operation can be conducted more aggressively where the head involved has more favorable OTRC and less aggressively where a head with a less favorable OTRC is involved.
摘要:
A perpendicular magnetic media includes a substrate, a patterned template, a seed layer and a magnetic layer. The patterned template is formed on the substrate and includes a plurality of growth sites that are evenly spaced apart from each other. The seed layer is formed over the patterned template and the exposed areas of the substrate. Magnetic material is sputter deposited onto the seed layer with one grain of the magnetic material nucleated over each of the growth sites. The grain size distribution of the magnetic material is reduced by controlling the locations of the growth sites which optimizes the performance of the perpendicular magnetic media.
摘要:
The magnetic head of the present invention includes a P1 pole having an opening formed therethrough, and a P2 pole that is formed over the opening. A second magnetic pole tip is positioned relative to the first magnetic pole such that the first magnetic pole is symmetrically disposed relative to the second magnetic pole tip. Induction coils may be helically wound around portions of the first and/or second magnetic poles, or, alternatively, a planar, spiral induction coil may be fabricated for use with the first and second magnetic poles. An enhanced embodiment includes a first magnetic pole tip piece having a length that defines the throat length of the magnetic head and a thickness that increases the gap at rearward portions of the second magnetic pole tip of the magnetic head.
摘要:
A method makes an inverted merged MR head with a second pole tip which is self-aligned with a top first pole tip. After forming a bottom first pole tip layer a top first pole tip is frame plated thereon with a width that defines a track width of the merged MR head. A photoresist layer, which is employed in the frame plating of the top first pole tip, is then soft baked which causes a photoresist opening above the top first pole tip to have sloping side edges which form a recess. An electrically-conductive sacrificial layer, such as copper, is then plated into the recess on top of the top first pole tip and the photoresist is removed. A forming layer, such as alumina, is then deposited and lapped so that the forming layer and the sacrificial layer have top surfaces that are flush with respect to one another. The sacrificial layer is then removed by an etchant that will not attack the materials of the pole tips and the forming layer. The forming layer now has a recess with sloping edges into which a gap layer, a seedlayer and a second pole tip layer are deposited. By this method the second pole tip is self-aligned with the top first pole tip with the second pole tip having a bottom that is substantially the same width as the top of the top first pole tip.
摘要:
In the present method for manufacturing a magnetic write head a focused ion beam (FIB) tool is utilized to mill the side edges of a P2 pole, in order to provide a narrowed track width. Prior to milling, a thin film layer of material is deposited upon the P2 pole tip. The milling boxes of the FIB tool are properly aligned upon the layer with reference to the location of the P2 pole tip. Milling of the lateral edges of the P2 pole tip is then conducted to the appropriate depth, and the layer of material is removed. The resulting P2 pole tip has sharp lateral edges, rather than the rounded edges that are produced in prior art FIB processing methods that do not utilize the thin film layer. In a preferred implementation, the FIB tool is utilized first to deposit the thin film layer and thereafter to perform the milling operation.
摘要:
A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head. In one method, a notching layer is employed where removal of a small corner of the notching layer provides the first pole piece with a notch. Other methods employ photoresist to protect the side of the first pole piece that is not to be notched, and/or oscillating the workpiece less than 360°. so that milling is more concentrated at the notch site.
摘要:
A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head. In one method, a notching layer is employed where removal of a small corner of the notching layer provides the first pole piece with a notch. Other methods employ photoresist to protect the side of the first pole piece that is not to be notched, and/or oscillating the workpiece less than 360°C. so that milling is more concentrated at the notch site.
摘要:
A magnetic head assembly has an open yoke type write head constructed on top of a read head so that the write head can be constructed with a very narrow track width without restraint by the requirements of the read head. The write head has first and second pole piece portions wherein the second pole piece portion has separate front and back layer portions. A coil layer is wrapped around only the first pole piece portion and the back layer portion so that the front layer portion can be constructed separately to provide a narrow track width. Further, in a preferred embodiment the front layer portion has a reduced thickness and a higher magnetic moment than the thickness and magnetic moment of the first pole piece portion and the back layer portion. Still further, in a preferred embodiment the first pole piece portion and the back layer portion are planar due to planarization of underlying layers.
摘要:
A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head. In one method, a notching layer is employed where removal of a small corner of the notching layer provides the first pole piece with a notch. Other methods employ photoresist to protect the side of the first pole piece that is not to be notched, and/or oscillating the workpiece less than 360°, so that milling is more concentrated at the notch site.
摘要:
A method makes an inverted merged MR head with a second pole tip layer which is self-aligned with a top first pole tip layer. After forming a bottom first pole tip layer, which is relatively thin and relatively wide, a top first pole tip layer is formed thereon with a width that defines the track width of the merged MR head. A second pole tip forming layer is formed on the top first pole tip layer and layers adjacent both sides of the top first pole tip layer. The forming layer and the top first pole tip layer are lapped so that their top surfaces are flush with one another. Ion milling is then implemented to mill the top first pole tip layer at a faster rate than the forming layer causing a recess that is defined by a top surface of the top first pole tip layer and inclined surfaces of the forming layer immediately adjacent thereto. After formation of a write gap layer in the recess a second pole tip layer is formed in a recess replicated by the write gap layer causing a bottom base portion of the second pole tip layer to be substantially the same width as the track width and aligned with the top first pole tip layer so that flux can be transferred between the pole tips more narrowly confined within the track width.