Abstract: A disk device according to one embodiment includes a magnetic disk, a magnetic head, and a flexible printed circuit board. The flexible printed circuit board is electrically connected to the magnetic head. The flexible printed circuit board includes a first layer, a second layer having conductive property, and a third layer having insulation property. The first layer includes a first surface having insulation property. The second layer overlays the first surface, and includes a first conductor and a second conductor spaced from the first conductor. The third layer covers at least a part of the first surface and at least a part of the second layer. The flexible printed circuit board is provided with a first hole that is located between the first conductor and the second conductor with spacing from the second layer and penetrates the third layer.

Abstract: According to one embodiment, a printed circuit board includes a first conductive layer on an insulating layer, including connection pads, a first mounting pad, a second mounting pad, a second wiring connecting the first mounting pad and one of the connection pads, and a first reinforcing pattern extending from the second mounting pad, a second conductive layer on another surface of the insulating layer, including a third wiring connected to one of the connection pads, and a conductive via connecting the second mounting pad and the third wiring. The second conductive layer includes a pad portion on the third wiring, opposed to the second mounting pad, and a third reinforcing pattern extending from the pad portion and opposed to the first reinforcing pattern.

Abstract: According to one embodiment, a disk device includes a magnetic disk, a magnetic head, a first FPC, and a second FPC. The first FPC includes first terminals. The magnetic head is mounted on the first FPC and electrically connected to at least one of the first terminals. The second FPC includes a surface, second terminals on the surface, and a first ground plane. The second terminals are individually bonded to the corresponding first terminals with a conductive bonding material. The first ground plane covers at least one of the second terminals in a direction orthogonal to the surface. The second terminals include a first read terminal through which an electric signal representing information read from the magnetic disk by the magnetic head passes. The first ground plane is located apart from at least a part of the first read terminal in a direction along the surface.

Abstract: A disk device according to one embodiment includes a magnetic disk, a magnetic head, and a flexible printed circuit board. The flexible printed circuit board is electrically connected to the magnetic head. The flexible printed circuit board includes a first layer, a second layer having conductive property, and a third layer having insulation property. The first layer includes a first surface having insulation property. The second layer overlays the first surface, and includes a first conductor and a second conductor spaced from the first conductor. The third layer covers at least a part of the first surface and at least a part of the second layer. The flexible printed circuit board is provided with a first hole that is located between the first conductor and the second conductor with spacing from the second layer and penetrates the third layer.

Abstract: according to one embodiment, a disk device includes a magnetic disk, a magnetic head, a first FPC, and a second FPC. The first FPC includes first terminals. The magnetic head is mounted on the first FPC and electrically connected to at least one of the first terminals. The second FPC includes a surface, second terminals on the surface, and a first ground plane. The second terminals are individually bonded to the corresponding first terminals with a conductive bonding material. The first ground plane covers at least one of the second terminals in a direction orthogonal to the surface. The second terminals include a first read terminal through which an electric signal representing information read from the magnetic disk by the magnetic head passes. The first ground plane is located apart from at least a part of the first read terminal in a direction along the surface.

Abstract: According to one embodiment, a method includes: supplying electrical energy to a first path by an inspection circuit with a short circuit between two first terminals through a first probe; and detecting an electrical characteristic on the first path by the inspection circuit. The two first terminals are included in a plurality of second terminals included in a flexible printed circuit board. The flexible printed circuit board includes: an electronic component including the inspection circuit and a plurality of third terminals; the plurality of second terminals; and a plurality of first wired lines connecting the plurality of second terminals and the plurality of third terminals. The first path is formed by: the two first terminals; two second wired lines connected to the two first terminals among the plurality of first wired lines; and two fourth terminals connected to the two second wired lines among the plurality of third terminals.

Abstract: A disk device according to one embodiment includes a magnetic disk, a magnetic head, and a flexible printed circuit board. The flexible printed circuit board is electrically connected to the magnetic head. The flexible printed circuit board includes a first layer, a second layer having conductive property, and a third layer having insulation property. The first layer includes a first surface having insulation property. The second layer overlays the first surface, and includes a first conductor and a second conductor spaced from the first conductor. The third layer covers at least a part of the first surface and at least a part of the second layer. The flexible printed circuit board is provided with a first hole that is located between the first conductor and the second conductor with spacing from the second layer and penetrates the third layer.

Abstract: According to one embodiment, a method includes: supplying electrical energy to a first path by an inspection circuit with a short circuit between two first terminals through a first probe; and detecting an electrical characteristic on the first path by the inspection circuit when the electrical energy is supplied to the first path. The two first terminals are included in a plurality of second terminals included in a flexible printed circuit board. The flexible printed circuit board includes: an electronic component including the inspection circuit and a plurality of third terminals; the plurality of second terminals; and a plurality of first wired lines connecting the plurality of second terminals and the plurality of third terminals. The first path is formed by: the two first terminals; two second wired lines connected to the two first terminals among the plurality of first wired lines; and two fourth terminals connected to the two second wired lines among the plurality of third terminals.

Abstract: According to one embodiment, a flexible printed wiring board includes a base insulation layer, first wirings W1 on the base insulation layer, an intermediate insulation layer overlapped with the first wirings, connection pads on the intermediate insulation layer, a cover insulation layer overlapped with the connection pads and the intermediate insulation layer and including openings through which the connection pads are exposed to the cover layer, and conductive vias MT electrically connecting the first wirings to at least a part of the connection pads respectively. The conductive vias are overlapped with the connection pads in a thickness direction of the flexible printed wiring board.

Abstract: According to one embodiment, a flexible printed wiring board includes a base insulation layer, first wirings W1 on the base insulation layer, an intermediate insulation layer overlapped with the first wirings, connection pads on the intermediate insulation layer, a cover insulation layer overlapped with the connection pads and the intermediate insulation layer and including openings through which the connection pads are exposed to the cover layer, and conductive vias MT electrically connecting the first wirings to at least a part of the connection pads respectively. The conductive vias are overlapped with the connection pads in a thickness direction of the flexible printed wiring board.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to the disk, and an integrated circuit configured to acquire a detection signal indicative of a first pattern of a first frequency of write data, change a first current of a second pattern of a write current corresponding to the first pattern on the basis of the detection signal, detect a third pattern of a second frequency which is greater than the first frequency from the write data, change a second current of a fourth pattern of the write current corresponding to the third pattern, and output the write current with the changed first current and the changed second current to the head.

Abstract: According to one embodiment, it is determined whether a STOAR element which performs microwave assistance for a magnetic disk apparatus is made to oscillate properly. When the STOAR element is oscillating when a current bias is applied, the resistance of the element increases. Therefore, in a head IC which outputs the current bias, a voltage applied to the STOAR element is sensed, and it is possible to determine that the STOAR element is oscillating when the voltage is increased to a threshold or more. Conversely, it is possible to determine that the STOAR element is not oscillating when the voltage is less than the threshold. In addition, it is possible to determine that oscillation has diminished, when the resistance decreases after the voltage reaches the threshold or more. Therefore, it is possible to make the STOAR element oscillate normally again, by boosting the STOAR element by a current.

Abstract: According to one embodiment, it is determined whether a STOAR element which performs microwave assistance for a magnetic disk apparatus is made to oscillate properly. When the STOAR element is oscillating when a current bias is applied, the resistance of the element increases. Therefore, in a head IC which outputs the current bias, a voltage applied to the STOAR element is sensed, and it is possible to determine that the STOAR element is oscillating when the voltage is increased to a threshold or more. Conversely, it is possible to determine that the STOAR element is not oscillating when the voltage is less than the threshold. In addition, it is possible to determine that oscillation has diminished, when the resistance decreases after the voltage reaches the threshold or more. Therefore, it is possible to make the STOAR element oscillate normally again, by boosting the STOAR element by a current.

Abstract: A head IC, which adjusts an amplitude level of a read signal of a head, for outputting to a read channel having an AGC amplifier, includes: a differential amplifier; an AGC circuit; external gain setting sections; and a switch. Since the AGC amplifier is disposed in the head IC, the amplitude from the head is automatically adjusted in the head IC, and the signal level, which enters the input dynamic range of the AGC amplifier of the read channel, can be adjusted. The AGC amplifier can be operated as a fixed gain amplifier using a gain value which is set from the outside, so the power consumption can be minimized even if automatic adjustment is performed.

Abstract: A head IC adjusts an amplitude level of a read signal of a head to adjust dispersion of the output characteristic of the head and to adjust the read signal within the input dynamic range of the AGC of a read channel. An AGC amplifier is installed in a head IC connected to a read channel and a feedback response speed of an AGC circuit of the head IC is set to be sufficiently slower than a feedback response speed of an AGC circuit of the read channel. Also a peak hold circuit and an amplitude limiting circuit are installed in the head IC, and gain is adjusted with a holding value of the peak hold circuit. An initial gain can therefore be stably adjusted at high-speed without being influenced by signals having a small amplitude on the medium.

Abstract: According to one embodiment, a signal amplifier amplifies a read signal read from a storage medium by a head, and includes an amplifier, a detector, and an impedance controller. The amplifier amplifies the read signal received from the head to obtain an amplified signal, and varies the input impedance of the read signal based on a control signal. The detector detects the frequency characteristic of the amplified signal output from the amplifier and determine the frequency characteristic as a first frequency characteristic. The impedance controller generates the control signal such that the first frequency characteristic detected by the detector becomes a predetermined second frequency characteristic.

Abstract: The heads have write head elements which record data onto a disk medium capable of coping with perpendicular magnetic recording and read head elements which reproduce data. The monitored band detecting unit sets a frequency band in a range from the signal band of the write data signal to the error rate worsening band on a lower level in which the error rate worsens as a monitored band, and detects a signal in the monitored band from among write data entered into the write amplifier. The determining unit discontinues the recording operation of the write amplifier upon determination that a detection signal of the monitored band detected by the monitored band detecting unit is larger than a prescribed threshold value and outputs a determination signal from the fault terminal to generate a fault event.

Abstract: A storage apparatus and a magnetic head driving device includes a recording/reproducing head including a write element and a magnetoresistive element, a driving circuit for driving the write element and the magnetoresistive element, and write wires and read wires which connect the recording/reproducing head to the driving circuit. The write wires and the read wires are disposed in parallel in at least a portion between the recording/reproducing head and the driving circuit. At a location between the recording/reproducing head and the driving circuit, either of the write wires and the read wires are disposed so that a polarity of the either of the write wires and the read wires is reversed with respect to a polarity of the other of the write wires and the read wires.

Abstract: A magnetic head drive device drives a heater element for controlling a protrusion amount of the magnetic head. The heater drive circuit of the heater element of the magnetic head, in which a read element, a write element and a heat element is included, is constructed by the PWM modulation method. A pair of heater wiring lines is made of a path in which the signal polarity is inverted. Therefore cross-talk noise, to the read wiring line, can be decreased even if PWM driving is executed.

Abstract: A head IC, which adjusts an amplitude level of a read signal of a head, for outputting to a read channel having an AGC amplifier, includes: a differential amplifier; an AGC circuit; external gain setting sections; and a switch. Since the AGC amplifier is disposed in the head IC, the amplitude from the head is automatically adjusted in the head IC, and the signal level, which enters the input dynamic range of the AGC amplifier of the read channel, can be adjusted. The AGC amplifier can be operated as a fixed gain amplifier using a gain value which is set from the outside, so the power consumption can be minimized even if automatic adjustment is performed.