Abstract: Described herein is a multilayer flex circuit having a first dual flex circuit and a second dual flex circuit where each one comprises an outer metal layer, a base insulation layer, and an inner metal layer. The base insulation layer is disposed between the outer metal layer and the inner metal layer. The inner metal layer of the first dual flex circuit is configured to face toward the inner metal layer of the second dual flex circuit. The multilayer flex circuit also includes a coupling layer that adhesively couples the inner metal layer of the first dual flex circuit to the inner metal layer of the second dual flex circuit. The multilayer flex circuit also comprises an electrically conductive material that electrically connects the inner metal layer of the second dual flex circuit to the inner metal layer of the first dual flex circuit.

Abstract: Described herein is a multilayer flex circuit having a first dual flex circuit and a second dual flex circuit where each one comprises an outer metal layer, a base insulation layer, and an inner metal layer. The base insulation layer is disposed between the outer metal layer and the inner metal layer. The inner metal layer of the first dual flex circuit is configured to face toward the inner metal layer of the second dual flex circuit. The multilayer flex circuit also includes a coupling layer that adhesively couples the inner metal layer of the first dual flex circuit to the inner metal layer of the second dual flex circuit. The multilayer flex circuit also comprises an electrically conductive material that electrically connects the inner metal layer of the second dual flex circuit to the inner metal layer of the first dual flex circuit.

Abstract: A flexible type electrical feed-through involves a flexible printed circuit (FPC) part constructed as a laminate structure of a base insulating layer, a conductor layer, and a cover insulating layer, where the FPC part is wrapped around a metal part, forming a connector assembly. 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. Multiple connector parts may be coupled to an inner side of the feed-through, to each mate with a respective flexible cable assembly electrically connected to a respective actuator of a multi-actuator hard disk drive. A floating board-to-board connector part may be coupled to the outer side of the feed-through, which in turn is electrically connected to a printed circuit board assembly of a hard disk drive, and which is able to tolerate connector mating misalignment.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Described herein is a connector assembly that comprises a head-gimbal assembly (HGA) tail connector, a flex connector, and an adhesive. The HGA tail connector comprises a pad support, an HGA pad coupled to the pad support, and an HGA trace coupled to the pad support and electrically coupled to the HGA pad. The flex connector comprises a substrate, comprising a first side and a second side, where the first side is opposite the second side. The flex connector also comprises a flex pad coupled to the first side of the substrate, a flex trace coupled to the second side of the substrate, and a via extending through the substrate from the first side to the second side. The via electrically couples the flex pad and the flex trace. Also, the adhesive adheres the HGA pad of the HGA connector in electrical contact with the flex pad of the flex connector.

Abstract: A method and apparatus is provided for extending a read bandwidth and increasing a high-frequency signal-to-noise ratio (SNR) of a front-end of a read path of a hard disk drive (HDD) by introducing a high impedance section at the front-end of the read path. The high impedance section may mitigate capacitive effects found at the front-end of the read path, thereby improving signal transfer by extending the read bandwidth.

Abstract: 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.

Abstract: 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.

Abstract: A disk drive has multiple preamplifiers (preamps) connected to the system-on-a-chip (SOC) by a common transmission line with resistors between the preamps and the SOC. Each preamp includes a read resistor at the output of each read amplifier, and a write resistor at the input of each write driver. The resistors may be programmable resistors located in the preamps. The read resistors are at the source of the signal to the transmission line and the write resistors are at the termination of the signal from the transmission line. The read and write resistors provide impendence matching with the transmission line and the SOC when one of the preamps is selected as active, which enables the SOC to operate seamlessly with a common transmission line connected to all preamps.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In one embodiment, a hard disk drive includes a magnetic disk medium, a magnetic head adapted for writing data to the magnetic disk medium, a mechanism (such as a detection circuit) adapted for detecting at least one recording condition of drive current provided to the magnetic head during writing operations, and an energy conversion element for controlling at least one recording characteristic of the magnetic head in response to the at least one detected recording condition. According to another embodiment, a method includes writing data to a magnetic medium using a magnetic head, detecting at least one recording condition of drive current provided to the magnetic head during the writing, and controlling at least one recording characteristic of the magnetic head during the writing using an energy conversion element in response to the at least one detected recording condition.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.