Abstract: A process for producing from olivine precipitated silica with controlled specific surface area and high degree of purity. The process comprises adding olivine in a controlled manner to a heated mineral acid solution; after separating undissolved olivine and filtering the silica is slurried in aqueous solution to obtain a low viscosity high solid content silica slurry that can be efficiently degritted and dried with a relatively low energy consumption. The obtained silica can be in powder, bead or granule form and preferably has a specific surface area of at least about 100 m2/g.

Abstract: An inductor assembly for use in RF and microwave circuits wherein the inductor is formed of a first spiral wound metal strip that is mounted on a flat surface of a quartz substrate. A metal strip is formed of copper and has a height above the flat surface that is about 30 microns.

Abstract: A monolithic integrated circuit (1) incorporating an inductive component (2) and comprising: a semiconductor substrate layer (2); a passivation layer (4) covering the substrate layer (2); metal contact pads (5) connected to the substrate (2) and passing through the passivation layer (4) in order to be flush with the upper face (6) of the passivation layer (4); which circuit also includes a spiral winding (20) which forms an inductor and lies in a plane parallel to the upper face (6) of the passivation layer (4), said winding (20) consisting of copper turns (21-23, 27, 28) having a thickness of greater than 10 microns, the winding ends forming extensions (12) which extend below the plane of the winding (20) and are connected to the contact pads (5).

Abstract: An inductor assembly for use in RF and microwave circuits wherein the inductor is formed of a first spiral wound metal strip that is mounted on a flat surface of a quartz substrate. The metal strip is formed of copper and has a height above the flat surface that is about 30 microns.

Abstract: Process for fabricating electronic components, of the variable capacitor or microswitch type, comprising a fixed plate (1) and a deformable membrane (20) which are located opposite each other, which comprises the following steps, consisting in: depositing a first metal layer on an oxide layer (2), said first metal layer being intended to form the fixed plate; depositing a metal ribbon (10, 11) on at least part of the periphery and on each side of the fixed plate (1), said ribbon being intended to serve as a spacer between the fixed plate (1) and the deformable membrane (20); depositing a sacrificial resin layer (15) over at least the area of said fixed plate (1); generating, by lithography, a plurality of wells in the surface of said sacrificial resin layer; depositing, by electrolysis, inside the wells formed in the sacrificial resin (15), at least one metal region intended to form the deformable membrane (20), this metal region extending between sections of the metal ribbon (10, 11) which are located o

Abstract: Apparatus and Method relating to a microcomponent such as an inductor in which copper segments are mounted in parallel channels of a non-conductive substrate so that the top surfaces of the segments are coplanar with the top surface of the substrate. A core material is placed over the top surface of the substrate and conductive arches are arranged to connect one end of each segment with the opposite end of an adjacent segment to form a coil that encircles the core.

Abstract: A slider incorporates welding studs for assembly with a spring arm. Each of the welding studs includes a base that is integral with the slider. The base has a controlled height and is made from a first material. Each of the welding studs further includes a meltable stud member which is placed on the base. The meltable stud member is made from a second material that has a melting point which is lower than that of the first material of the base.

Abstract: A magnetic recording medium and a thin film planar magnetic head form an assembly. The magnetic recording medium of the assembly includes a magnetic coating having a residual magnetization value (Mr) and a thickness value (t) which together form a high product value (Mr)(t) which is preferably greater than about 1.8 memu/cm.sup.2. This coating also has a high coercive field value of Hc which is preferably greater than about 2,200 Oe. The ratio formed by dividing the (Mr)(t)product value by this coercive field value Hc((Mr)(t)/Hc) is preferably approximately 0.7.times.10.sup.-3 memu/cm.sup.2 /Oe or 0.8.times.10.sup.-3 memu/cm.sup.2 /Oe. The product of the (mr)(t) product value and the coercive field value Hc ((Mr)(t)(Hc)) is preferably greater than approximately 4000 Oe.times.memu/cm.sup.2.

Abstract: A magnetic slider assembly includes a spring arm; a magnetic slider including a plurality of welding studs, each of the welding studs including a base which is integral with the slider, the base having a controlled height and being made from a first layer of material which is not meltable at a welding temperature. Each of the welding studs further include a meltable stud member placed on the base, the meltable stud member including the second layer of material positioned on the first layer of material and having a melting point lower than that of the first layer of material and which is meltable at the welding temperature such that after welding, the meltable stud member forms a weld and a minimum parallel spacing between the slider and the spring arm which is substantially equal to the controlled height of the base. The second layer may be formed of either an electrolytically grown material or an etched material that is located on the first layer.

Abstract: A planar magnetic head including two pole pieces separated by a head gap with a longitudinal multilayer magnetoresistance component MR comprising extending longitudinally beneath the pole pieces and the head gap and separated from the pole pieces by an insulating layer. The MR component is arranged in contact with a pair of spaced apart electrical conductors for connecting said MR component in circuit with a source of electrical power to cause current to flow through said MR component in its lengthwise direction.

Abstract: Process for making a plane magnetic head and magnetic head obtained by this process.A hard protective layer surrounds polar parts. The non-magnetic spacer and polar parts are flush with the level of this protective layer. This layer is preferably made of diamond like carbon.

Abstract: A magnetic read head having a multilayer magnetoresistant element and a concentrator, and a method of production the magnetic read head. The magnetic head includes a multilayer magnetoresistant element across a head gap of the concentrator positioned to the rear of pole pieces defining the gap of the head. Such a magnetic head may find particular application to magnetic recording.

Abstract: A high reluctance magnetic head is disclosed.According to the invention, the concentrators are separated from the pole pieces by an amagnetic layer incorporating more particularly a conductive layer.The application is directed to magnetic recording.

Abstract: A magnetic layer 16 adopts the shape of an insulating ridge 14 and a multilayer magnetoresistor (MR) functions in a longitudinal mode and underlies the magnetic layer. The device is used for magnetic recording and can be a read-only head or a read-write head.

Abstract: A process of producing a magnetic read head which includes a multilayer magnetoresistant element and a concentrator. The magnetic read head is produced to include a multilayer magnetoresistant element across a head gap of the concentrator positioned to a rear of pole pieces defining the gap of the head. Such a magnetic head may find particular application in magnetic recording systems.

Abstract: A slider for magnetic recording includes at least one ski with a front portion and a rear portion, a read and/or write head located at the rear portion of the slider, the front portion of each ski having first and second steps with, respectively, first and second risers. The first riser of the first step forms with a longitudinal direction of the ski a first angle of between approximately 10.degree. and approximately 60.degree. and the second riser of the second step forms with the longitudinal direction of the ski a second angle which differs from the first angle and is between approximately 20.degree. and approximately 80.degree.. The height of the first riser is between approximately 20 nm and approximately 200 nm and the height of the second riser is between approximately 200 nm and approximately 2 .mu.m.

Abstract: Magnetic read/write head having a writing-compensated magneto-resistant element.In the invention, the head includes, beneath a magnetoresistant element (MR), a conductor element (40) and preferably an additional magnetic layer (44) perforated by an opening (46). The conductor element (40) is in series with the writing coil and connected in such a way that, in the magnetoresistant element, the magnetic field resulting from the passage of the current in the conductor element opposes the writing leakage field.

Abstract: Process for producing a semiconductor field detector magnetic head and head obtained by this process. On a silicon substrate (30) is produced a semiconductor sensor (32) and then the magnetic circuit of the head (36,48,50,52,54). Application to magnetic recording. (FIG.