International Business Machines Corporation

Hgst Netherlands, B.v.

Western Digital Technologies, Inc.

Hitachi Global Storage Technologies Netherlands B.v.

Maxtor Corporation

Other

Seagate Technology Incorporated

Sandisk Technologies Inc.

Albert John Wallash

John Thomas Contreras

Steven H Voldman

Timothy Scott Hughbanks

Neil Leslie Robertson

Peter Beverley Phipps

Erhard Theodor Schreck

Earl Albert Cunningham

Glen A Garfunkel

Rehan Ahmed Zakai

Michael Paul Salo

Steven Harry Voss

David Malcolm Hannon

Jeffrey B Brown

Nickolas Christopher Apuzzo

Raymond Patrick Mallette

Paul Sheldon Tyler

Samir Elias Abboud

Robert G Biskeborn

Hardayal Singh Gill

David John Seagle

Tsann Lin

Ching Hwa Tsang

Satya Prakash Arya

Nobumasa Nishiyama

Xinzhi Xing

Ryan Thomas Davis

Reginald B Wilcox, Jr

Sanford J Lewis

Hui He

Carol Yoshiko Inouye

Ravinder Singh Ajmani

Robert Owen Barr

Hong Zhu

Tzong-Shii Pan

Eric Alan Eckberg

Ferdinand Hendriks

Satoshi Nakamura

A David Erpelding

Surya Narayan Pattanaik

Christopher H Bajorek

Stephen A Jove

Samir Y Garzon

Ikuya Tagawa

Kazuhiro Nagaoka

Alain M Desouches

Robert E Eaton

Yuji Soga

Hin P Lee

Lydia Baril

Antony Nguyen

Kenneth Allen

Shajith Musaliar Sirajudeen

Ronald G Parkinen

Robert R Suchomel

Jack Nguyen

Richard George Hirko

Jason Wolfson

Junjia Liu

John P Herber

Ferruh Gocemen

To protect memory cards, such as SD type cards, and similar devices from Electrostatic Discharge (ESD), the input pads of the device include points along their edges that are aligned with correspond points on a conductive frame structure mounted adjacent the input pad to form a spark gap. The input pads are connected to a memory controller or other ASIC over signal lines that include a diode located between the input pad and the ASIC and a resistance located between the input pad and the diode. The resistance and diode are selected such that an ESD event at an input pad triggers a discharge across the spark gap before it is transmitted on to the ASIC, while also allowing a high data rate for signals along the signal line.

Spark gap electrostatic discharge (ESD) protection for memory cards

Disclosed herein are printed circuit boards with at least one signal trace situated over or under a reference plane. The reference plane includes a broadband common-mode filter that comprises looping and parallel structures etched into the reference plane. The looping structure includes an even number of side arms, and the parallel structure comprises an even number of interior arms, wherein each of the side arms extends toward the parallel structure, and each of the interior arms extends toward the looping structure. The at least one signal trace is substantially parallel to the side arms and to the interior arms, and is situated between a first half of the even number of side arms and a second half of the even number of side arms and between a first half of the even number of interior arms and a second half of the even number of interior arms.

Compact broadband common-mode filter

Disclosed herein are printed circuit boards with embedded solenoid filters through which signal traces pass to filter unwanted noise and electromagnetic interference. A printed circuit board comprises a least three layers, a solenoid embedded within the at least three layers, and at least one trace extending through the solenoid. The insertion loss characteristics of the solenoid filter can be tuned by modifying the number of turns in the solenoid(s) and the width of the solenoid(s). The solenoid filter may comprise multiple solenoids connected in series, with adjacent solenoids having opposite wind directions. Surface components may be included on the board to tune the insertion loss further.

Solenoid filter built into a printed circuit board

Disclosed herein are suspension assembly structures for data storage devices that include physical or virtual crossovers of the pairs of differential signal traces to improve immunity to crosstalk and other interference. In an embodiment, the suspension assembly structure comprises a first trace for carrying a first component of a current to a differential transducer on a slider, a second trace for carrying a second component of the current to the differential transducer on the slider, and third and fourth traces for providing a differential write current to a writer of the data storage device, wherein the first trace physically crosses over the second trace at a first distance from a tail of the suspension assembly structure.

Suspension adjacent-conductors differential-signal-coupling attenuation structures

Disclosed herein are printed circuit boards (PCBs) with patterned ground structure filters and data storage devices comprising such PCBs. Each PCB comprises a resonator having an L-shape or a zig-zag shape in a plane of the printed circuit board and at least one signal trace. The resonator has a first dimension and a second dimension in the plane of the printed circuit board. A portion of the at least one signal trace is situated over the resonator and is separated by a distance from the resonator by a dielectric material. In some embodiments, at least part of the portion of the at least one signal trace extends in a same direction as the first dimension (in the case of an L-shaped resonator) or tracks the zig-zag shape of the resonator (in the case of a zig-zag-shaped resonator).

Patterned ground structure filter designs with improved performance

The present disclosure generally relates to a shielded three-layer patterned ground structure in a PCB. The PCB may be disposed in a hard disk drive. To reduce costs, PCBs are being made with only four total layers separated by dielectric material. Conductive traces in PCBs can have the problem of common mode current flowing through the traces and thus increasing the magnitude of EMI noise. By providing a shielded three-layer patterned ground structure, not only is the cost reduced, but so is the common mode current and the magnitude of EMI noise, all without any negative impact to the differential signal.

Shielded three-layer patterned ground structure

The present disclosure generally relates to a shielded patterned ground structure in a PCB. The PCB may be disposed in a hard disk drive. Conductive traces in PCBs can have the problem of common mode current flowing through the traces and thus increasing the magnitude of EMI noise. By providing a shielded patterned ground structure, the common mode current is reduced as is the magnitude of EMI noise, yet there is no negative impact to the differential signal.

Shielded patterned ground structure filter for EMI reduction

A flex cable with a shielding layer for use in a disk drive is described. The flex cable connects the actuator to the system electronics. The flex cable has a shielding layer that provides RF shielding for the embedded signal traces. In embodiments the shielding layer is connected to the baseplate or device enclosure ground at one or more selected points on the bracket end of the flex cable that are separated from the signal paths. Embodiments of the shielding layer include rows of apertures or windows that are aligned with selected signal traces such as the read and write signal traces and serve to maintain the desired impedance in the read and write signal traces. In one embodiment the shielding layer extends over a selected portion of the flex cable that includes the bracket end and the area under the first stiffener.

Shielded flex cable for use in a disk drive

An interconnect between the read/write circuitry and the read/write head in a magnetic recording hard disk drive (HDD) for two-dimensional magnetic recording (TDMR) has the read sensor signal lines located on a lower level of a bi-level structure of conductive lines. Common return lines are located on an upper level above the signal lines and on the lower level between the signal lines. All of the return lines on the upper level are connected to one another by cross-connect lines, and vias are located along the interconnect and connect the upper return lines with the lower return lines and with the ground plane of the interconnect's electrically conductive substrate. The interconnect is a coaxial-like interconnect because the return lines are located around each signal line and thus shield each signal line from the other signal lines, much like the outer conductive shield of a coaxial cable.

Integrated lead suspension (ILS) for two-dimensional magnetic recording (TDMR) disk drive

A method, apparatus, and system are provided for implementing a write head device for writer-to-disk contact detection and spacing sensing of recording heads in hard disk drives (HDDs). A write head device, such as a spin-torque oscillator (STO), is provided between a main pole tip and a surrounding magnetic shield of the writer in the recording head. A pair of connections is provided to the magnetic shield and the main pole of the writer, and resistance of the write head device is measured to detect writer to disk spacing and contact.

Implementing write head device for contact detection and spacing sensing

A 'split-substrate' design is described for the metal ground layer in the suspension for a slider for use in a disk drive that reduces crosstalk from signals being transmitted on the conductive traces and allows externally induced interference to be shunted away from sensitive traces along selected portions of the suspension. In embodiments of the invention a slit formed in the metal ground layer to provide two parallel ground paths respectively on the left and right sides of the selected portion of the suspension. By positioning interference signal generating traces like writer traces on one side of the slit, that side becomes the noisy ground path leaving the other side as a 'quiet' ground path. The shape, positioning and grounding of the split substrate structure can shunt return/ground currents created by external RFI into the noisy leg and thereby shield the quiet leg.

Suspension design with split substrate for improved interference signal immunity

A flexible cable assembly (FCA) has a stiffener layer positioned in electrical contact with an electrical ground feature of the FCA, and a head stack assembly (HSA) may include a suspension tail electrically connected to the stiffener layer of the FCA, thus providing a robust ground path between the read/write head and the arm or E-block of the HSA. Additional efficient grounding techniques may include directly electrically connecting the suspension tail to the arm via a conductive adhesive, directly electrically connecting the FCA stiffener layer to the arm via a conductive screw, and/or directly electrically connecting the ground feature and the stiffener layer of the FCA to the arm using a ground post or screw.

Grounding for a hard disk drive suspension tail

An electronic device enclosure configured to shield against electromagnetic interference (EMI). The electronic device enclosure includes an electronic device-enclosure base and at least one laterally disposed blunt boss. The electronic device-enclosure base includes a bottom, and sides and attached to the bottom in a boxlike configuration. The laterally disposed blunt boss is configured so as to be disposed between, and to couple electrically, a side of the electronic device-enclosure base and a vertical flange of an electronic device-enclosure cover. The electronic device-enclosure base and the electronic device-enclosure cover are configurable with respect to said laterally disposed blunt boss to shield an interior space enclosed by the electronic device-enclosure base and the electronic device-enclosure cover against EMI at a resonant frequency of a slot of the electronic device enclosure. A hard-disk drive including a disk enclosure configured to shield against EMI and a method for assembling the hard-disk drive are also provided.

Electronic device enclosure configured to shield against electromagnetic interference

A method, apparatus, and system for implementing spin integrated spin-torque oscillator (STO) with an interface bias control for hard disk drives. Bias circuitry for a spin-torque oscillator (STO) is integrated with a slider for microwave assisted magnetic recording (MAMR). The slider includes read and write transducers and the integrated STO bias circuitry controls a bias potential applied to a write return pole to the write transducer with respect to a disk.

Implementing integrated spin-torque oscillator and interface bias control for hard disk drives

A magnetic tape head including a transducer disposed between a substrate, a recession between the transducer and the substrate, where the recession is formed at least by wear from a magnetic tape. The magnetic tape head also includes a heater disposed in the transducer. The heater thermally expands the transducer at a particular location such that the recession is reduced at the particular location.

Reducing recession by heating a magnetic tape head

Growing community of inventors

Morgan Hill, CA, United States of America

Albert John Wallash