Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a wet chemical etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: A low-noise toroidal thin film head ("TFH") device has low coil resistance and inductance, especially suitable for very high magnetic recording areal densities and channel frequencies. The length of a toroidal coil turn is only about 20-30% that of the length of an average turn in the conventional planar spiral coil design. This allows either reduction of the device thermal noise (by about 6 dB) and/or increase of the device operational frequency bandwidth (by a factor of 3-5). The toroidal coil coupling efficiency between each turn and the magnetic core is practically 100%, thereby improving the write and read-back efficiencies. In one embodiment a non-via large back-closure contact area is provided between the bottom and top magnetic poles along their entire back-side width, and all other open branches and loose ends in the magnetic circuit are eliminated. The magnetic core has a gradual, smooth toroidal (or a horse-shoe) shape with no loose ends, nooks, crevices, or sharp corners.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to .ltoreq.1 .mu.m.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to .ltoreq.1 .mu.m.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and an alumina etchant. The deep alumina etching enables the formation of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a wet chemical etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to .ltoreq.1 .mu.m.

Abstract: A low-noise toroidal thin film head ("TFH") device has low coil resistance and inductance, especially suitable for very high magnetic recording areal densities and channel frequencies. The length of a toroidal coil turn is only about 20-30% that of the length of an average turn in the conventional planar spiral coil design. This allows either reduction of the device thermal noise (by about 6 dB) and/or increase of the device operational frequency bandwidth (by a factor of 3-5). The toroidal coil coupling efficiency between each turn and the magnetic core is practically 100%, thereby improving the write and read-back efficiencies. In one embodiment a non-via large back-closure contact area is provided between the bottom and top magnetic poles along their entire back-side width, and all other open branches and loose ends in the magnetic circuit are eliminated. The magnetic core has a gradual, smooth toroidal (or a horse-shoe) shape with no loose ends, nooks, crevices, or sharp corners.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact in two areas, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) down to <1 .mu.m.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a dilute (1:2) HF in water etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and an alumina etchant. The deep alumina etching facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a wet chemical etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: An inductive pinched-gap thin film head (TFH) device having pole-tips which are in substantial contact along their side-edges, thereby precisely defining a pinched-gap segment. The substantial contact between the pole-tips' side-edges effectively eliminates all flux lines emanating from the edges and corners during the write operation. The write magnetic field is thus precisely confined to across the pinched-gap segment. As a result, the written medium track width is accurately defined by the width of the pinched-gap segment with high degree of magnetization coherency and virtual elimination of the track-edge noise. The improved (medium) signal-to-noise ratio facilitates substantial increase of the track density. Photolithographic definition and etching of the gap-vias to the bottom pole-tip, followed by deposition of the top pole-tip, facilitates precise and consistent control of the width of the pinched-gap segment (and the written track) drawn to .ltoreq.1 .mu.m.

Abstract: A precision high rate electroplating cell comprising a rotating anode/jet assembly (RAJA) immersed in the electrolyte and having high pressure electrolyte jets aimed at the substrate (cathode). The high pressure jets facilitate efficient turbulent agitation at the substrate's surface, even when it consists of complex shapes or mask patterns. High aspect ratio areas receive similar degree of agitation (and replenishment) as areas of lower aspect ratios. As a result, thickness and composition micro-uniformities are substantially improved while utilizing significantly higher current densities and plating rates.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a dilute (1:2) HF in water etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: A thin film magnetic read/write head is manufactured using a multi-layered sacrificial mask in a pole tip alignment process. The sacrificial mask includes a layer of metal deposited upon the magnetic upper pole tip. Subsequent sacrificial mask layers include nickel-iron alloy or photoresist. Following an ion milling alignment process, residual sacrificial mask layers are removed using a process in which the medal layer is selectively chemically etched away from the thin film magnetic head.

Abstract: A thin film magnetic read/write head is manufactured using a multi-layered sacrificial mask in a pole tip alignment process. The sacrificial mask includes a layer of metal deposited upon the magnetic upper pole tip. Subsequent sacrificial mask layers include nickel-iron alloy or photoresist. Following an ion milling alignment process, residual sacrificial mask layers are removed using a process in which the medal layer is selectively chemically etched away from the thin film magnetic head.

Abstract: The seed-layer, or metallization layer, used to form the coil winding in a thin film head (TFH) by electrodeposition, is removed from between individual winding turns by selective etching with an etchant which preferentially, or selectively, attacks the seed-layer while leaving the coil winding, insulation, and gap materials essentially intact. A suitable combination of compatible materials which can be used as the seed-layer, coil winding, and etchant, respectively, in practicing this invention comprises nickel-iron Permalloy, copper, and a mixture of nitric acid and phosphoric acid diluted in pure water. Other combinations of materials and types of etching processes suitable for this invention are also disclosed.

Abstract: A magnetic recording member with a thin metallic antifriction protection overcoat formed over a magnetic layer. The overcoat is soft ductile and low stress and includes a metal selected from the group consisting of palladium, platinum, silver, gold, cadmium, indium, tin and lead or an alloy of one or more of these metals, and may include less than 20 percent by weight of antimony, bismuth, thallium or copper to improve wear resistance or impede corrosion. In one preferred embodiment the antifriction overcoat is an alloy of silver, lead and antimony formed with N layers where 10.ltoreq.N.ltoreq.40. The even layers are richer in a selected metal of the alloy than the odd layers in order to produce adjacent layers with different lattice or microstructural and associated mechanical properties so that there tends to be parallel shear between adjacent layers under sharing stress of head impact or friction.

Abstract: A magnetic recording member with a thin metallic antifriction protection overcoat formed over a magnetic layer. The overcoat is soft ductile and low stress and includes a metal selected from the group consisting of palladium, platinum, silver, gold, cadmium, indium, tin and lead or an alloy of one or more of these metals, and may include less than 20 percent by weight of antimony, bismuth, thallium or copper to improve wear resistance or impede corrosion. In one preferred embodiment the antifriction overcoat is an alloy of silver, lead and antimony formed with N layers where 10.ltoreq.N.ltoreq.40. The even layers are richer in a selected metal of the alloy than the odd layers in order to produce adjacent layers with different lattice or microstructural and associated mechanical properties so that there tends to be parallel shear between adjacent layers under shearing stress of head impact or friction.