International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Timothy J Moran

Richard Hsiao

Ian Robson McFadyen

James Devereaux Jarratt

Emo Hilbrand Klaassen

Jyh-Shuey (Jerry) Lo

Vladimir Nikitin

Edward Hin Pong Lee

Eric Edward Fullerton

Jean Fompeyrine

Howard Gordon Zolla

Klaas Berend Klaassen

Rolf Allenspach

Michael Paul Salo

Joseph Francis Smyth

John I Kim

Samuel Wei-san Yuan

Jean Pierre Locquet

Maria Seo

Jyh-Shney (Jerry) Lo

Edward Hing Pong Lee

First, second and third pole tip components of a write head are formed with the second pole tip located between the first and third components and a write gap layer located between the first and second pole tip components. The second pole tip is formed with a width that defines a track width of the write head. The third pole tip component is formed with top and bottom surfaces wherein the bottom surface interfaces a top surface of the second pole tip component and has a width equal to the track width and wherein the top surface of the third pole tip has a width greater than the track width.

Magnetic head assembly that has an air bearing surface

The present invention provides a method of manufacturing a magnetoresistive read head which reduces electrostatic discharge and allows measurement of gap resistances in the head.

Method of reducing ESD damage in thin film read heads which enables measurement of gap resistance

A magnetic transducer including an electrically conductive shield (ECS) which is disposed between the substrate and first magnetic shield is described. The ECS is preferably embedded in an insulating undercoat layer. The ECS is preferably electrically isolated from the magnetic sensor element and is externally connected to a ground available in the disk drive through the arm electronics. Two alternative ways for connecting the ECS to a ground are described. In one embodiment which is only effective with single-ended input type arm electronics, the ECS is connected to a ground through a via to a lead pad for the read head which is connected to the ground of the arm electronics. In a second and more preferred embodiment a separate lead pad is included on the head to allow the ECS to be connected to electronic or case ground when the head is installed in the arm. The extent of the ECS should be sufficiently large to cover the read head portion of the transducer, i.e., from the edge of the first magnetic shield to the outer edges of the read contact pads, but should preferably not cover the write head pads.

Magnetic transducer with electrically conductive shield for reducing electromagnetic interference

Method of making a T-shaped write head with less side writing

A first read gap layer has a resistance R between a first shield layer and one of the first and second lead layers of a read head and the second read gap layer has a resistance R between a second shield layer and said one of the first and second lead layers of the read head. A connection is provided via a plurality of resistors between a first node and each of the first and second shield layers wherein the plurality of resistors includes at least first and second resistors R and R and the first node is connected to said one of the first and second lead layers. A second node is located between the first and second resistors R and R . An operational amplifier has first and second inputs connected to the first and second nodes respectively so as to be across the first resistor R and has an output connected to the first node for maintaining the first and second nodes at a common voltage potential. In a first embodiment the first and second shield layers are shorted together. A test instrument is then employed for determining the combined parallel resistance of the resistors R and R by having a first side of the test instrument connected to the first node and the second side connected to each of the first and second shield layers. In the second embodiment a third resistor R is connected between the second node and one of the shield layers, such as the second shield layer. The test instrument can determine the resistances of the first and second gap layers separately by being connected between the first node and the first shield layer for the resistance of the first gap layer or between the first node and the second shield layer for the resistance of the second gap layer.

Device and method of reducing ESD damage in thin film read heads which enables measurement of gap resistances and method of making

The present invention concerns at least an antiferromagnetic layer, which is in direct contact with a ferromagnetic layer for inducing an exchange bias in the ferromagnetic layer. Thus, the ferromagnetic layer is pinned by the antiferromagnetic layer, also referred to as the pinning layer. The antiferromagnetic or pinning layer comprises a compound from the group of orthoferrites, which show a variety of advantages. For example, these antiferromagnets can have a N&eacute;el temperature T ranging from at least 623 K to 740 K depending on the compounds, and they can display a weak ferromagnetic moment. Therefore, a magnetic device comprising the mentioned structure can be used properly in an environment of a high operating temperature. The compound can be described by the formula RFe TM O with R a rare earth element or Yttrium, and TM a transition metal which can be one element of the groups IB to VIII. The compound can be also doped by an element S being an element with another valence, such as Barium, Nickel, Strontium, Calcium, Potassium, or Sodium in compound R S FeO .

Magnetic device with ferromagnetic layer contacting specified yttrium or rare earth element oxide antiferromagnetic layer

The improved process according to the invention prepares samples for subsequent imaging by directing the FIB beam so that its incident angle is not parallel to the planar boundaries between the materials with different etch rates. This nonparallel alignment has the effect of evening out the etch rate, since most of the key beamlets cut more than one type of material. SEM images of the resulting samples are easier to interpret than those produced by the prior art since the obscuring effect of curtaining is reduced. This allows greater accuracy of measurement from the image obtained by an SEM. A method according to a preferred embodiment of the invention is used to prepare a pole piece tip of a magnetic transducer so that the bottom width may be more accurately measured.

Method of pole tip sample preparation using FIB

A method for forming a magnetic head to solve the curved electrodeposited write gap layer problem by initially fabricating the write gap layer to be wider than the intended final P pole tip width. Ion milling the sides of the P pole tip structure is then performed to remove the curved outer portions of the write gap layer and to thereby fabricate a P pole tip having the desired pole tip width. Specifically, following the electrodepositing of the write gap layer and P pole tip thereon, an ion milling step is conducted to remove material from the sidewalls of the P pole tip including the write gap layer. The ion milling step is preferably conducted utilizing a broad beam ion milling device that is directed to the surface of the substrate upon which the magnetic heads are being fabricated. Preferably, the ion beam is directed at an angle of approximately 70&deg; away from normal to the substrate surface such that milling of the head side surfaces is efficiently accomplished. Following the ion milling step the curved edges of the write gap layer are removed and the P pole tip width is narrowed to its desired dimension. Thereafter, further well known fabrication steps are conducted to complete the fabrication of the magnetic head.

Method for reducing magnetic head write gap curvature of a plated write gap

A high throughput method for producing the narrow track width inductive head is also provided, whereby the heads may be manufactured in substantial volumes. The new head may be merged or piggy-backed MR or GMR heads, comprising a first pole piece, P , and a second pole piece, P , and is distinctly characterized by write track width is significantly reduced by a preliminary ion milling process before P notching is performed. The preliminary step utilizes an ion milling process to trim the write track width, P B, at an angle between 45 to 85 degrees from the wafer normal. The MR head may then undergo conventional P notching.

Method for manufacturing a magnetic write head

To protect the MR read head element from ESD damage during wafer level manufacturing, a lead from the MR element is electrically connected to one or both of the read head element shields during manufacturing. In a preferred embodiment of the present invention, the electrical connection is fabricated in the kerf area between adjacent magnetic heads as they are fabricated upon a wafer substrate. Thereafter, when the magnetic heads are separated by saw cutting through the kerf areas, the electrical connections are thereby removed, such that the MR element electrical leads and the shields are electrically isolated. In an alternative embodiment, one or more of the shields, as well as the MR element leads can also be electrically connected to the substrate upon which the magnetic head is fabricated. In further alternative embodiments, the electrical connection between one or more of the shields and the MR element electrical lead can be fabricated within the magnetic head area, rather than in the kerf area, and a suitable resistance is fabricated into the interconnecting circuit. In this embodiment, the electrical interconnection between the MR element electrical lead and one or more of the shields has a pre-designed electrical resistance and it remains in the magnetic head following fabrication.

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San Jose, CA, United States of America

Timothy J Moran