Abstract: A thin film magnetic head is provided in which a magnetic yoke assembly is built up, layer by layer, atop a substrate using semiconductor thin film techniques. A lower yoke assembly is first fabricated including a lower magnetic layer situated on the substrate and first and second side poles built up vertically from the ends of the lower magnetic layer. An insulative pedestal surrounded by a frame is formed at the top of the lower yoke assembly and extends above the uppermost lateral plane of the yoke assembly. A diamond-like carbon (DLC) wear layer is deposited atop the pedestal. First and second pole support wells are excavated in the DLC layer so as to expose the first and second side poles therebelow, and further to receive first and second pole supports, respectively, therein. First and second pole extension members are situated on the first and second pole support members, respectively, with a non-magnetic gap region being situated between the first and second pole extension members.

Abstract: A thin film magnetic head assembly is provided which includes a plurality of thin film heads situated atop a common substrate. An insulative main body is built up layer by layer on the substrate. A plurality of magnetic yokes exhibiting different geometries are situated on the substrate and within the main body. The magnetic yokes are built up layer by layer at the same time that the insulative main body is fabricated. A plurality of coil structures are situated within the main body and are magnetically coupled to respective magnetic yokes. The head assembly also includes a pedestal of insulative material situated atop the main body and exhibiting a lateral dimension less than that of the main body. The pedestal protrudes upwardly away from the main body and substrate. The magnetic yokes each include a pole piece pair situated atop the pedestal, each pole piece pair including first and second magnetic pole pieces. Each pole piece pair exhibits a different geometry than another pole piece pair.

Abstract: A thin film helical conductor coil assembly includes an electrically-nonconducting ceramic substrate having a substantially planar surface and separated first and second magnetic elements which mutually bound a volume of the ceramic substrate. The thin film conductor coil assembly also includes a thin film magnetic core, which magnetically connects the first magnetic element to the second magnetic element. The thin film magnetic core, which overlies the substantially planar surface of the ceramic substrate, is constructed from a compliant electroplated magnetic material. The thin film conductor coil assembly further includes an electroplated thin film helical coil which traverses about the thin film magnetic core and forms a conductive path from a first terminal to a second terminal.

Abstract: A method is provided for fabricating a thin film magnetic head including a plurality of layered components. One or more vias are formed through an electrically insulative substrate which includes first and second opposed major surfaces. The via includes an interior side surface. The via is filled with electrically conductive material which is situated in contact with the interior side surface of the via. A via connective member is thus formed which extends between the first and second surfaces of the substrate. A protective via cap is formed atop the via connective member to protect the via connective member from subsequent etching operations. A thin film head is formed atop the first surface of the substrate by building up components of the head layer by layer. This forming a thin film head step includes the step of forming a coil for exciting the head by etching, with an etchant, portions of a layer of electrically conductive material within the head.

Abstract: A thin film magnetic head is fabricated on a substrate by depositing a seed layer on the substrate. A lower magnetic layer is plated on the substrate in an opening provided in an insulative layer which is deposited on the seed layer. A plurality of magnetic layers are plated at one end of the lower magnetic layer to build-up and form a first side pole by using the above seed layer as a seed. Another plurality of magnetic layers are plated at the other end of the lower magnetic layer to build-up and form a second side pole by using the same seed layer as a seed. The first and second side poles thus formed include upper and lower ends, the lower ends being plated to the ends of the lower magnetic layer. A first upper pole is plated to the upper end of the first side pole. The first upper pole includes a gap end facing the second side pole. A gap region of nonmagnetic material is deposited adjacent the gap end of the first upper pole.

Abstract: A thin film "third axis" magnetic head is provided which is resistant to head wear which heads typically experience when operating in close proximity to a magnetic recording media. A relatively soft magnetic core is formed on the third axis surface of a hard insulative substrate. The magnetic core includes a gap region at the edge of the third axis surface. The gap region and a portion of the magnetic core adjacent the gap region are covered with a protective layer of hard material, such as diamond-like carbon (DLC). In this manner, a ruggedized sandwich-like head structure is formed including the hard substrate, the enclosed relatively soft magnetic core and the protective layer of hard DLC material.

Abstract: A thin film magnetic head is provided in which a magnetic yoke assembly is built up, layer by layer, atop a substrate using semiconductor thin film techniques. A lower yoke assembly is first fabricated including a lower magnetic layer situated on the substrate and first and second side poles built up vertically from the ends of the lower magnetic layer. An insulative pedestal surrounded by a frame is formed at the top of the lower yoke assembly and extends above the uppermost lateral plane of the yoke assembly. A diamond-like carbon (DLC) wear layer is deposited atop the pedestal. First and second pole support wells are excavated in the DLC layer so as to expose the first and second side poles therebelow, and further to receive first and second pole supports, respectively, therein. First and second pole extension members are situated on the first and second pole support members, respectively, with a non-magnetic gap region being situated between the first and second pole extension members.

Abstract: A thin film magnetic head is fabricated on a substrate by depositing a seed layer on the substrate. This seed layer is advantageously used as a common seed for a plurality of magnetic head related structures which are built-up on the substrate. A lower magnetic layer is plated on the substrate in an opening provided in an insulative layer which is deposited on the substrate. The aforementioned seed layer is used as the seed for this lower magnetic layer. A plurality of magnetic layers are plated at one end of the lower magnetic layer to build-up and form a first side pole by using the above seed layer as a seed. Another plurality of magnetic layers are plated at the other end of the lower magnetic layer to build-up and form a second side pole by using the same seed layer as a seed. The first and second side poles thus formed include upper and lower ends, the lower ends being plated to the ends of the lower magnetic layer. A first upper pole is plated to the upper end of the first side pole.

Abstract: A thin film magnetic head is provided in which a magnetic yoke assembly is built up, layer by layer, atop a substrate using semiconductor thin film techniques. A lower yoke assembly is first fabricated including a lower magnetic layer situated on the substrate and first and second side poles built up vertically from the ends of the lower magnetic layer. An insulative pedestal surrounded by a frame is formed at the top of the lower yoke assembly and extends above the uppermost lateral plane of the yoke assembly. A diamond-like carbon (DLC) wear layer is deposited atop the pedestal. First and second pole wells are excavated in the DLC layer so as to expose the first and second side poles therebelow and to form a DLC gap region between the first and second side poles. First and second magnetic poles are then formed in the first and second pole wells, respectively.

Abstract: A fiber comprising at least about 80% by weight linear low density polyethylene and having a melting point >109.degree. C. is disclosed. Also disclosed are thermally consolidated fiber structures comprising (1) at least about 3% by weight, based on the total weight of the structure, of lower melting binder fibers comprising at least 80% by weight linear low density polyethylene, and (2) not more than 97% by weight, based on the total weight of the structure, of nonmelting fibers, or fibers having a melting point higher than the linear low density polyethylene fibers. The fiber structures can be in the form of multifilament yarns, woven or nonwoven textile fabrics, carpets, or laminates. The linear low density polyethylene binder fibers in the structures preferably have a melting point <109.degree. C.

Abstract: A stamp (1) is disclosed which has a luminescent coating (9, 11) which over the area of the coating is such that there are a plurality of coated spaced regions interspersed with non-coated regions. The coating may be applied as a grid or cross hatching or other suitable arrangement. The coating is applied over an area which is of sufficient size relative to the thickness and density of the coating to permit the coating to be detected by a postage stamp luminescence detection device. The non-coated regions over which the coating extends being of sufficient area to permit penetration and drying of a stamp cancelling ink. A method of producing such stamp is also disclosed.

Abstract: A thin film head is disclosed which is miniaturized to fit within a reduced size window or circumferential slot in a rotary head assembly. The thin film head and window or slot can be made so small that undesired tape cupping into the window or slot is significantly reduced. The thin film head includes a substrate of electrically insulative material. In one embodiment, a substantially helical thin film coil structure is situated atop the substrate. A magnetic core extends through the coil structure so that the coil structure can magnetically excite the core. The core includes first and second side pole members. A protective cocoon of electrically insulative material covers the coil structure and the core except for ends of the first and second side pole members. The cocoon includes an upper planar surface which exposes the ends of the first and second side pole members to permit coupling thereto by a magnetic gap structure.

Abstract: A method is provided for fabricating a thin film magnetic head on a substrate. A seed layer formed on the substrate and advantageously used as a common seed for a plurality of magnetic head related structures which are built-up on the substrate. A lower magnetic layer is plated on the substrate in an opening provided in an insulative layer which is deposited on the substrate. The aforementioned seed layer is used as the seed for the plating of this lower magnetic layer. A plurality of magnetic layers are plated at one end of the lower magnetic layer to build-up and form a first side pole by again using the aforementioned seed layer as a seed. Another plurality of magnetic layers are plated at the other end of the lower magnetic layer to build-up and form a second side pole by using the same seed layer as a seed. The first and second side poles thus formed include upper and lower ends, the lower ends being plated to the ends of the lower magnetic layer.

Abstract: Process for the preparation of 2,2'-(1-methyl-1,2-ethanediylidine)bis[hydrazine carboximidamide] bya) removing impurities from aminoguanidine bicarbonate;b) reacting the aminoguanidine bicarbonate with methylglyoxal dimethyl acetal in an aqueous isopropyl medium; andc) purifying the 2,2'-(1-methyl-1,2-ethanediylidene)bis[hydrazine carboximidamide] by crystallization from an acidic aqueous-isopropanol medium.

Abstract: A thin film helical conductor coil assembly includes an electrically-nonconducting ceramic substrate having a substantially planar surface and separated first and second magnetic elements which mutually bound a volume of the ceramic substrate. The thin film conductor coil assembly also includes a thin film magnetic core, which magnetically connects the first magnetic element to the second magnetic element. The thin film magnetic core, which overlies the substantially planar surface of the ceramic substrate, is constructed from a compliant electroplated magnetic material. The thin film conductor coil assembly further includes an electroplated thin film helical coil which traverses about the thin film magnetic core and forms a conductive path from a first terminal to a second terminal.

Abstract: A thin film magnetic head is provided in which a magnetic yoke assembly is built up, layer by layer, atop a substrate using semiconductor thin film techniques. A lower yoke assembly is first fabricated including a lower magnetic layer situated on the substrate and first and second side poles built up vertically from the ends of the lower magnetic layer. An insulative pedestal surrounded by a frame is formed at the top of the lower yoke assembly and extends above the uppermost lateral plane of the yoke assembly. A diamond-like carbon (DLC) wear layer is deposited atop the pedestal. First and second pole wells are excavated in the DLC layer so as to expose the first and second side poles therebelow and to form a DLC gap region between the first and second side poles. First and second magnetic poles are then formed in the first and second pole wells, respectively.

Abstract: A method for fabricating a thin film magnetic head is provided in which a magnetic yoke assembly is built up, layer by layer, atop a substrate using semiconductor thin film techniques. The lower yoke assembly is first formed and includes a lower magnetic layer situated on the substrate and first and second side poles built up vertically from the ends of the lower magnetic layer. An insulative pedestal surrounded by a frame is formed at the top of the lower yoke assembly and extends above the uppermost lateral plane of the yoke assembly. First and second pole pieces are plated on the first and second side poles through openings in the pedestal. A diamond-like carbon (DLC) protective wear layer is deposited atop the pedestal and pole pieces. The wear layer and pole pieces are machined to form the upper head surface. The magnetic pole pieces recede below the surface of the wear layer during machining.