Patents Assigned to Fuji Electric Device Technology Co., Ltd.
  • Publication number: 20100086808
    Abstract: A method of forming a protective film of a magnetic recording medium is provided that achieves a good bonding characteristic with a lubricant film and at the same time, suppressing adhesion of contamination gases, to attain a reduced thickness of the magnetic recording medium. The method includes forming a protective film on a lamination including a substrate and a metallic film layer formed on the substrate, by means of a plasma CVD method using a raw material of a hydrocarbon gas, and performing a surface treatment on the protective film. The surface treatment includes a plasma treatment with argon gas, and a plasma treatment with a gas containing at least nitrogen gas.
    Type: Application
    Filed: August 27, 2009
    Publication date: April 8, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventor: Naruhisa NAGATA
  • Publication number: 20100084372
    Abstract: The invention provides a method of forming a concavo-convex pattern by partly removing a magnetic layer and a carbon protective layer in an intermediate product of a magnetic recording medium having at least the magnetic layer and the protective layer formed on a substrate surface, wherein the magnetic layer is partly removed to form the concavo-convex pattern by a dry etching method using a etching gas of a mixture gas of argon and a deposition gas containing one or more types of carbon compounds. Also disclosed is a method of manufacturing a patterned medium type magnetic recording medium employing the method of forming a concavo-convex pattern.
    Type: Application
    Filed: August 26, 2009
    Publication date: April 8, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventor: Katsumi TANIGUCHI
  • Publication number: 20100086733
    Abstract: An aluminum alloy substrate having nano-holes in an ordered arrangement is disclosed, as well as a method of manufacturing such an aluminum alloy substrate. The aluminum alloy substrate of the invention includes a substrate, a first underlayer, a second underlayer, and an aluminum-containing layer including a lower layer portion composed of an amorphous aluminum alloy and an amorphous surface layer portion containing alumina, the surface layer portion having a plurality of nano-holes formed thereon.
    Type: Application
    Filed: October 7, 2009
    Publication date: April 8, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventor: Hitoshi NAKATA
  • Publication number: 20100086809
    Abstract: A magnetic recording medium exhibiting a high recording density performance is disclosed. The perpendicular magnetic recording medium has a soft magnetic underlayer, a first seed layer, a second seed layer, an intermediate layer, a granular magnetic recording layer, a non-granular magnetic recording layer, a protective layer, and a lubricant layer laminated on a nonmagnetic substrate in this order. The first seed layer contains cobalt, nickel, and at least one element selected from a group consisting of Si, Cr, V, Zr, Nb, Ta, Ti, Cu, and Mo, and the second seed layer contains nickel, chromium, and at least one element selected from a group consisting of Si, V, Zr, Nb, Ta, Ti, Cu, and Mo.
    Type: Application
    Filed: September 2, 2009
    Publication date: April 8, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventor: Yoshiyuki KUBOKI
  • Patent number: 7692239
    Abstract: A MIS-type semiconductor device has reduced ON-resistance by securing an overlapping area between the gate electrode and the drift region, and has low switching losses by reducing the feedback capacitance. The MIS-type semiconductor device includes a p-type base region, an n-type drift region, a p+-type stopper region in the base region, a gate insulation film on the base region, a gate electrode on the gate insulation film, an oxide film on the drift region, a field plate on the oxide film, and a source electrode. The position (P) of the impurity concentration peak in base region is located more closely to the drift region. The oxide film is thinner on the side of the gate electrode. The field plate is connected electrically to the source electrode, the spacing (dg) between the gate insulation film and the stopper region is 2.5 ?m or narrower, and the minimum spacing (x) between the drain region and the stopper region is 5.6 ?m or narrower.
    Type: Grant
    Filed: May 12, 2006
    Date of Patent: April 6, 2010
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Tatsuji Nagaoka
  • Patent number: 7682991
    Abstract: A method of manufacturing a silicon carbide semiconductor device includes forming a trench for a MOS gate in an SiC substrate by dry etching. Thereafter, the substrate with the trench is heat treated. The heat treatment includes heating the substrate in an Ar gas atmosphere or in a mixed gas atmosphere containing SiH4 and Ar at a temperature between 1600° C. and 1800° C., and thereafter in a hydrogen gas atmosphere at a temperature between 1400° C. and 1500° C. The present manufacturing method smoothens the trench inner surface and rounds the corners in the trench to prevent the electric field from localizing thereto.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: March 23, 2010
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Yasuyuki Kawada, Takeshi Tawara, Tae Tawara
  • Publication number: 20100067152
    Abstract: The voltage of a detection resistor connected to the drain of a low-side switching device is normally a negative voltage, but a positive voltage appears when a countercurrent occurs in an abnormal state. A current comparator monitors the voltage of the detection resistor, transmits high output to an AND circuit whole the voltage of the detection resistor is a negative voltage to maintain the output voltage of the current comparator in a low state when an output signal of a driver can be transmitted to the low-side switching device, and allows the output voltage of the current comparator in a low state when the voltage of the detection resistor becomes a positive voltage, thereby forcibly turning off the low-side switching device.
    Type: Application
    Filed: August 10, 2009
    Publication date: March 18, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventors: Yasunori Nakahashi, Masayuki Yamadaya, Satoshi Yamane
  • Publication number: 20100067262
    Abstract: A switching power source device for supplying power to a load includes a series resonant circuit, a plurality of main switch elements or main switch element groups for switching a current. path of the series resonant circuit, a transformer for inducing a secondary current from the series resonant circuit, a plurality of synchronous rectification switch elements for rectifying the secondary current, a maximum on width control circuit for ordering a start and a completion of a maximum on width to the synchronous rectification switch element in synchronization with a timing of turning on the main switch elements Or the main switch element groups, and a synchronous control circuit. The circuit controls an on period of the synchronous rectification switch element so as to turn on the synchronous rectification switch element in synchronization with a particular timing, and turn off in synchronization with another timing.
    Type: Application
    Filed: August 18, 2009
    Publication date: March 18, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Jian Chen, Koji SONOBE
  • Patent number: 7679213
    Abstract: An AC to DC converter circuit includes a main circuit including a first circuit and a second circuit connected to an AC power supply in parallel to each other, the first circuit including diodes and a switching device, the second circuit including diodes and a switching device. The switching devices are controlled to be ON and OFF corresponding to the input voltage polarity discriminated with an input voltage polarity discriminator such that two DC outputs are obtained from one AC power supply. The AC to DC converter circuit reduces the semiconductor devices, through which a current flows, facilitates reducing the losses caused therein, improving the conversion efficiency thereof, and reducing the size, weight and manufacturing costs of the cooling means thereof.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: March 16, 2010
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Kazuaki Mino
  • Publication number: 20100059028
    Abstract: A semiconductor device includes an IGBT, a constant voltage circuit, and protection Zener diodes. The IGBT makes/breaks a low-voltage current flowing in a primary coil. The constant voltage circuit and the protection Zener diodes are provided between an external gate terminal and an external collector terminal. The constant voltage circuit supplies a constant gate voltage to the IGBT to thereby set a saturation current value of the IGBT to a predetermined limiting current value. The IGBT has the saturation current value in a limiting current value range of the semiconductor device.
    Type: Application
    Filed: August 11, 2009
    Publication date: March 11, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventor: Katsunori Ueno
  • Publication number: 20100055845
    Abstract: A power semiconductor module and a method of manufacture thereof includes lead a frame carrying lead having inner and outer lead portions. The outer lead portions, which are connected by soldering to semiconductor chips simultaneously, eliminate the need for using bonding wires. Since no bonding wire is used for connecting the leads and the semiconductor chips, a sufficient current capacity is obtained. The bonding between an insulating circuit board and the semiconductor chips and the bonding between the semiconductor chips and the leads can be made simultaneously in a single step of reflow-soldering. As a result, the mounting time can be shortened and the power semiconductor module can be manufactured more efficiently.
    Type: Application
    Filed: October 9, 2009
    Publication date: March 4, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Osamu IKAWA, Eiji MOCHIZUKI, Masayuki SOUTOME, Norio ARIKAWA
  • Publication number: 20100055503
    Abstract: Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co—Ni—Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.
    Type: Application
    Filed: July 28, 2009
    Publication date: March 4, 2010
    Applicants: TOHOKU UNIVERSITY, FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Takehito SHIMATSU, Hideo SATO, Osamu KITAKAMI, Satoshi OKAMOTO, Hajime AOI, Hiroyasu KATAOKA
  • Publication number: 20100044749
    Abstract: A semiconductor device and a method of fabrication thereof includes a bidirectional device having a high breakdown voltage and a decreased ON voltage. An n-type extended drain region is formed in the bottom surface of each trench. A p-type offset region is formed in each split semiconductor region. First and second n-source regions are formed in the surface of the p-type offset region. This reduces the in-plane distance between the first and second n-source regions to thereby increase the density of cells. The breakdown voltage is maintained along the trenches. This increases the resistance to high voltages. Channels are formed in the sidewalls of the trenches by making the voltage across each gate electrode higher than the voltage across each of the first and second n-source electrodes. Thus, a bidirectional LMOSFET through which current flows in both directions is achieved. The LMOSFET has a high breakdown voltage and a decreased ON voltage.
    Type: Application
    Filed: November 4, 2009
    Publication date: February 25, 2010
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Mutsumi KITAMURA, Naoto FUJISHIMA
  • Patent number: 7667445
    Abstract: An integrated circuit for controlling a switching power supply includes a signal input terminal in addition to a switching input terminal that is also provided in a conventional integrated circuit and is a terminal to switch IC operation modes using an external control signal. The switching input terminal signal is made valid when the signal input terminal voltage is higher than a threshold voltage, such that mode switching using an external control signal is enabled. When the signal input terminal voltage is lower than the threshold voltage, mode switching is automatically conducted by switching a MOSFET ON or OFF using output signals of portions of a comparator connected to a feedback terminal to which an output voltage of a power supply device is applied.
    Type: Grant
    Filed: June 22, 2006
    Date of Patent: February 23, 2010
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Nobuyuki Hiasa
  • Publication number: 20100040772
    Abstract: A method of manufacturing a magnetic recording medium that includes a nonmagnetic underlayer, a magnetic layer, a protective layer, and a lubricant layer sequentially laminated on a nonmagnetic substrate. The method includes applying a lubricant onto the protective layer to form the lubricant layer, which includes ejecting shots of a heated lubricant liquid onto the protective layer from a nozzle. The heated lubricant liquid contains a perfluoropolyether lubricant, and each shot is of a quantity in a range of 0.1 to 10 pico liters.
    Type: Application
    Filed: August 13, 2009
    Publication date: February 18, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventor: Yoshihito Osawa
  • Publication number: 20100038675
    Abstract: A power semiconductor device that realizes high-speed turnoff and soft switching at the same time has an n-type main semiconductor layer that includes lightly doped n-type semiconductor layers and extremely lightly doped n-type semiconductor layers arranged alternately and repeatedly between a p-type channel layer and an n+-type field stop layer, in a direction parallel to the first major surface of the n-type main semiconductor layer. A substrate used for manufacturing the semiconductor device is fabricated by forming trenches in an n-type main semiconductor layer 1 and performing ion implantation and subsequent heat treatment to form an n+-type field stop layer in the bottom of the trenches. The trenches are then filled with a semiconductor doped more lightly than the n-type main semiconductor layer for forming extremely lightly doped n-type semiconductor layers. The manufacturing method is applicable with variations to various power semiconductor devices such as IGBT's, MOSFET's and PIN diodes.
    Type: Application
    Filed: August 11, 2009
    Publication date: February 18, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventor: Koh Yoshikawa
  • Patent number: 7662529
    Abstract: An electrophotographic photoconductor in which generation of a ghost phenomenon caused by exposure is avoided and potential change before and after continuous printings is insignificant. A functionally separated type electrophotographic photoconductor includes at least a charge generation layer containing a charge generation agent and a charge transport layer containing a charge transport agent, the two layers being sequentially laminated on a conductive substrate. A ratio of the maximum intensity of a halo pattern to a peak intensity of a maximum diffraction peak is less than 0.3 in an X-ray diffraction pattern obtained by a powder method using Cu K? line of a test coating film produced from a test coating liquid that is prepared by adding the charge transport agent into a coating liquid for the charge generation layer in an equal mass of the charge transport agent to a mass of the charge generation agent.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: February 16, 2010
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Mikio Yamazaki
  • Patent number: 7663886
    Abstract: An electronic circuit device includes a lower-side substrate formed with a main circuit; an upper-side substrate formed with a drive control circuit that drivingly controls the main circuit; a support body positionally fixed above the lower-side substrate with resin in a hardened state; and a case having a peripheral portion with an outer surface that has at least a portion of an external lead-out terminal of the drive control circuit and the main circuit thereon, and a substrate storage space that accommodates the lower-side substrate on a side inward from the peripheral portion.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: February 16, 2010
    Assignees: Aisin AW Co., Ltd., Fuji Electric Device Technology Co., Ltd.
    Inventors: Kazuo Aoki, Junji Tsuruoka, Seiji Yasui, Yasushi Kabata, Shin Soyano
  • Publication number: 20100033288
    Abstract: Two coil conductors of the same spiral shape are cut out from a lead frame. The two coil conductors are disposed back to back so that the front of a first coil conductor is superimposed over the rear of a second coil conductor. Central end portions of the first and second coil conductors are connected to each other through a connection layer. Outer end portions of the spirals of the first and second coil conductors are connected to corresponding ones of first and second terminals of the thin inductor, respectively. A sintered green sheet as a magnetic substance is disposed in gaps between the first and second coil conductors. In this manner, the invention can provide a thin inductor small in size, strong in mechanical strength and inexpensive, a method of producing the thin inductor, and an ultra small size power conversion apparatus using the thin inductor.
    Type: Application
    Filed: July 10, 2009
    Publication date: February 11, 2010
    Applicant: Fuji Electric Device Technology Co., Ltd.
    Inventors: Takeshi Yokoyama, Takafumi Yamada, Tomonori Seki, Masaharu Edo
  • Publication number: 20100028791
    Abstract: An electrophotographic photoconductor that stabilizes electrical performances and prevents generation of image faults such as memories, irrespective of types of organic materials of resin binder and charge transport material, and variation of temperature and humidity of the operation environment. An electrophotographic photoconductor includes at least a photosensitive layer formed over a conductive substrate, wherein the photosensitive layer contains a cyclohexane dimethanol-diaryl ester compound represented by the formula (I): in formula (I), each of R1 through R10 represents independently, a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group of carbon number of from 1 to 5, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkoxy group of carbon number of from 1 to 5.
    Type: Application
    Filed: April 5, 2007
    Publication date: February 4, 2010
    Applicant: Fuji Electric Device Technology Co.,Ltd.
    Inventors: Ikou Takaki, Yoichi Nakamura, Kazuki Nebashi