Western Digital Technologies, Inc.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Netherlands B.v.

Nhk Spring Co., Ltd.

Kazuhiro Nagaoka

Nobumasa Nishiyama

Kimihiko Sudo

Seong-Hun Choe

Yuji Soga

John Thomas Contreras

Satoshi Nakamura

Takako Hayakawa

Yuta Onobu

Takehito Nagata

Nobuyuki Okunaga

Teruhiro Nakamiya

Albert John Wallash

Hajime Arai

Tatemi Ido

Rehan Ahmed Zakai

Eiji Soga

Futa Sasaki

Masahiro Kishimoto

Tomohisa Okada

A hard disk drive flexible printed circuit (FPC) includes a plurality of fingers extending from a main portion, with each finger having a first wiring layer including a first electrically conductive trace layout, a second wiring layer including a second electrically conductive trace layout, and a base film interposed between the first and second wiring layers, where the first conductive trace layout includes at least one thermally conductive protective island overlaying a respective portion of the second trace layout to provide a protective thermal barrier to the base film. Hence, maximum temperatures across various layers of the FPC laminate can be reduced, damage to the FPC prevented, and manufacturing yields improved.

Flexible printed circuit copper overlay for temperature management

A flexible printed circuit (FPC) for a hard disk drive includes a plurality of electrical traces, whereby aggressor traces are isolated from victim traces to avoid crosstalk that could degrade signals. Aggressor traces may be positioned together at one of the edges of each of the top wiring layer and the bottom wiring layer, physically isolated from victim traces. Aggressor traces may be grouped together at either the top wiring layer or the bottom wiring layer, with the victim traces positioned on the layer opposing the aggressor traces. With aggressor and victim traces routed on the same wiring layer, aggressor traces may be routed away from the victim traces with multi-layer routing, by way of vias.

Flexible printed circuit finger layout for low crosstalk

A hard disk drive flexible printed circuit (FPC) includes a plurality of fingers extending from a main portion, with each finger having a thermally-conductive stiffener, at least one wiring layer over the stiffener, and a cover film over the at least one wiring layer, where the centroid of the stiffener is offset from the centerline of the cover film. Thus, utilizing the heat-sink characteristics of the stiffener, temperature differences among the upper and lower electrical pads of the FPC resulting from a heat-based interconnection procedure can be reduced and the temperatures across the FPC finger made more uniform, damage to the FPC prevented, and soldering yields improved.

Flexible printed circuit offset finger stiffener

Embodiments disclosed herein generally relate to hermetic electrical connectors used in hard disk drives. The hermetic electrical connector includes a barrier structure having a first plurality of connecting pads disposed on a first surface of the barrier structure and a second plurality of connecting pads disposed on a second surface of the barrier structure opposite the first surface. A plurality of conductors is disposed within the barrier structure, and each conductor is coupled to a connecting pad of the first plurality of connecting pads and a corresponding connecting pad of the second plurality of connecting pads. The barrier structure further includes a dielectric material between the first and second surfaces, and one or more layers embedded in the dielectric material. The addition of the layers helps choke the helium gas flow, thus improving sealing of the electrical connector while maintaining high-speed electrical transmission.

Hermetic sealed electrical connector with high-speed transmission for hard disk drive

A low permeability electrical feed-through involves a laminate structure having alternating conductive and insulating layers with a conductive through-hole positioned therethrough, by which a lower connector pad is electrically connected with an upper connector pad. Such a feed-through may be used at an interface between a hermetically-sealed internal environment, such as in a lighter-than-air gas filled data storage device, and the external environment. An insulating layer is positioned and configured such that an associated horizontal leak path can meet an allowable feed-through leak rate, while the collection of layers is configured such that an associated vertical leak path can meet the feed-through leak rate.

Low permeability electrical feed-through

Hermetic sealing with high-speed transmission for hard disk drive

A test coupon includes a pseudo element circuit which is constituted of a main circuit section and an adjusting section. The main circuit section includes a first pattern conductor and second pattern conductors. The first pattern conductor and the second pattern conductors overlap one another with a dielectric layer interposed therebetween. The first pattern conductor electrically conducts to the second pattern conductors. The main circuit section represents the R-component and the L-component of an equivalent circuit, and is a dominant circuit element which determines a signal waveform. The adjusting section includes linear conductors. A peak of a voltage waveform is suppressed by the R- and L-components of the adjusting section.

Pseudo flexure for disk drive and method of testing electronic circuit for disk drive

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

A multiple-segment transmission line in a hard disk drive enables a wider optimization range of the slope, duration and amplitude of the transmission line overshoot (TLO) wave shape. There is a first segment with two traces for connection to the write driver circuitry, an end segment with two traces for connection to the write head and at least two intermediate segments. The number of traces in a segment is different from the number of traces in the segments to which the segment is immediately connected. There is an even number of traces in each segment and the traces in each segment are interleaved. The number of segments and the number of traces in each segment can be selected to achieve the desired impedance levels for the different segments to achieve the desired wave shape for the TLO. All of the traces on the transmission line are preferably coplanar.

Magnetic recording disk drive with write driver to write head transmission line with multiple segments having different numbers of conductive traces

A head-stack assembly. The head-stack assembly includes: a magnetic-recording head; a lead-suspension supporting the magnetic-recording head on an actuator arm; a metal plate coupled with the actuator arm; a resin layer disposed on the metal plate; a flexible-printed-circuit board disposed on the resin layer, and substantially perpendicularly connected to the lead-suspension; a arm-electronics module disposed on the flexible-printed-circuit board configured to shape a write-signal current waveform of a write signal to said magnetic-recording head; transmission lines disposed on the flexible-printed-circuit board configured to transmit the write signal to, and a read-back signal from, the lead-suspension; and, a single intermediate conductor layer that is disposed between the resin layer and the flexible-printed-circuit board, and having a planar shape substantially facing a bottom of the arm-electronics module and a bottom of the transmission lines.

Growing community of inventors

Fujisawa, Japan

Kazuhiro Nagaoka