Patents by Inventor Mikito Sakakibara

Mikito Sakakibara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050179106
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Application
    Filed: April 12, 2005
    Publication date: August 18, 2005
    Applicant: Sanyo Electric Company, Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Patent number: 6914280
    Abstract: Since a 5 GHz-band broadband has a frequency twice that of 2.4 GHz, the parasitic capacitance greatly influences deterioration in isolation of a switching device used in this frequency region. Therefore, to improve isolation, a shunt FET is added to the device. The switching device also includes a protecting element that has a first n+-type region, an insulating region and a second n+-type region. This protecting element is connected in parallel between two electrodes of the shunt FET. Since electrostatic charges are discharged between the first and second n+-type regions, the electrostatic energy reaching an operation region of the shunt FET can be reduced without an increase in parasitic capacitance.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: July 5, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Publication number: 20050121730
    Abstract: With a microwave FET, an incorporated Schottky junction capacitance or PN junction capacitance is small and such a junction is weak against static electricity. However, with a microwave device, the method of connecting a protecting diode cannot be used since this method increases the parasitic capacitance and causes degradation of the high-frequency characteristics. In order to solve the above problems, a protecting element, having a first n+-type region—insulating region—second n+-type region arrangement is connected in parallel between two terminals of a protected element having a PN junction, Schottky junction, or capacitor. Since discharge can be performed between the first and second n+ regions that are adjacent each other, electrostatic energy that would reach the operating region of an FET can be attenuated without increasing the parasitic capacitance.
    Type: Application
    Filed: September 8, 2003
    Publication date: June 9, 2005
    Inventors: Tetsuro Asano, Mikito Sakakibara, Toshikazu Hirai
  • Patent number: 6903426
    Abstract: A semiconductor switching device includes two FETs with different device characteristics, a common input terminal, and two output terminals. A signal transmitting FET has a gate width of 500 ?m and a signal receiving FET has a gate width of 400 ?m. A resistor connecting a gate electrode and a control terminal of the signal transmitting FET is tightly configured to provide expanding space for the FET. Despite the reduced size, the switching device can allow a maximum power of 22.5 dBm to pass through because of the asymmetrical device design. The switching device operates at frequencies of 2.4 GHz or higher without use of shunt FET.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: June 7, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Toshikazu Hirai, Mikito Sakakibara
  • Patent number: 6891267
    Abstract: A semiconductor switching circuit device includes a field effect transistor having a source electrode, a gate electrode and a drain electrode, a first electrode pad connected to the source electrode or the drain electrode, and a second electrode pad connected to the source electrode or the drain electrode which is not connected to the first electrode pad. The device also includes a third electrode pad receiving a DC voltage and applying the DC voltage to the field effect transistor, a first insulating layer covering the field effect transistor, a metal layer disposed above the first insulating layer and connected to the third electrode pad, and a second insulating layer disposed on the metal layer. The third electrode pad may be a control terminal pad, a ground terminal pad or a terminal pad receiving a constant DC power voltage. The metal layer may be a flat sheet, a lattice or a comb-like structure.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: May 10, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara
  • Patent number: 6867115
    Abstract: The conventional compound semiconductor switching device is prone to have a large chip size as the gate width needs to be large for achieving a low insertion loss and the separation between the connecting pad and the circuit wiring needs to be larger than 20 ?m for obtaining a proper isolation between them. The overall chip size is reduced, first, by reducing the gate width of the switching FET operating at frequencies above 2.4 GHz to 700 ?m or smaller together with the omission of the shunt FET, and, then, by reducing the separation between the connecting pad and the circuit wiring to 20 ?m or smaller. This reduction of the separation is made possible by the introduction of an insulating film and a impurity region between the outermost portion of the connecting pad and the substrate for preventing the extension of the depletion layer.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: March 15, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Toshikazu Hirai, Takayoshi Higashino, Koichi Hirata, Mikito Sakakibara
  • Patent number: 6853072
    Abstract: Posts are disposed at the surroundings of an FET and a shield metal supported by the posts is placed above the FET to create a void between the FET and the shield metal. Since the separation between the FET and the shield metal is small, the resin does not enter the void. A resin layer cover the shield metal. The shield metal is connected to an electrode pad that receives a DC control signal. Although high frequency signals that are applied to the FET may leak between the source and drain electrodes of the FET through the resin layer covering the FET even when the FET is switched off, the void and the shield metal prevent such signal leakage.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: February 8, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara
  • Patent number: 6833616
    Abstract: A semiconductor chip is mounted on a wiring board that has a two-layer lead structure. One of the leads used for receiving input signals is disposed on the lower layer and runs underneath the semiconductor chip forming an U-shaped wiring line while other leads are disposed on the upper layer. Because one of the upper layer leads for receiving input signals is disposed in the U-shaped pocket of the U-shaped wiring line of the lower layer, the relative positioning of corresponding terminals can be changed into a reversal of the positioning of the electrode pads of the chip connected to the terminals. Furthermore, one of the upper layer lead for receiving control signals is placed between the chip and the lower layer lead underneath the chip to prevent high frequency signal interference.
    Type: Grant
    Filed: December 5, 2002
    Date of Patent: December 21, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Hideyuki Inotsume, Haruhiko Sakai, Shigeo Kimura
  • Patent number: 6833608
    Abstract: Two different switches with two different signal input schemes are fabricated by mounting the same semiconductor chip on the same lead pattern. Two of the leads of the lead pattern provides space enough for wire-bonding connection to corresponding electrode pads on the semiconductor chip at both ends of the semiconductor chip. Because each of electrode pads can be connected to the corresponding lead at either end of the semiconductor chip, two sets of bonding wire connection between the leads and the electrode pads provides two different switches with two different signal inputs scheme.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: December 21, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Hideyuki Inotsume, Haruhiko Sakai, Shigeo Kimura
  • Patent number: 6818969
    Abstract: A semiconductor device includes four input terminals, four leads extending from the corresponding input terminals and a semiconductor chip that has a first circuit and a second circuit and is mounted on one of the leads. The lead having the semiconductor chip thereon bends in a plane of the substrate so that an end portion and a mid portion of the lead are exposed on one side of the semiconductor chip. One of the input electrode pads of the first circuit is connected to the end portion of the lead by a bonding wire. The end portion of the lead is on the opposite side of the mid portion of the lead with respect to one of the leads that is connected to one of the input electrode pads of the second circuit by a bonding wire. This configuration achieves a crossing wiring structure within the packaging. By changing the connection of bonding wires, the crossing wiring structure is easily undone.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: November 16, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Hideyuki Inotsume, Haruhiko Sakai, Shigeo Kimura
  • Publication number: 20040222469
    Abstract: With a microwave FET, the internalized Schottky junction capacitance or pn junction capacitance is small and these junctions are weak against static electricity. However, with a microwave device, a protecting diode could not be connected since the increase of parasitic capacitance resulting from this method causes degradation of the high frequency characteristics. Therefore, to eliminate this problem, a semiconductor device is provided, wherein two paths, extending from a gate electrode pad to a gate electrode on an operating region, are arranged, with one path running near a source electrode pad, the other path running near a drain electrode pad, and at the respective parts where a path becomes close to a pad, the abovementioned protecting elements are connected between the gate electrode and source electrode and between the gate electrode and drain electrode to improve the electrostatic breakdown voltage of the FET from approximately 100V to 700V.
    Type: Application
    Filed: February 6, 2004
    Publication date: November 11, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Toshikazu Hiraj
  • Publication number: 20040223274
    Abstract: Since improvement measures are not taken in regard to the electrostatic breakdown voltage, electrostatic breakdown voltages, between the common input terminal IN—first control terminal Ctl-1, between the common input terminal IN—second control terminal Ctl-2, between the first control terminal Ctl-1—the first output terminal OUT1, and between the second control terminal Ctl-2—the second output terminal OUT2, where both ends of gate Schottky junctions of FETs are lead out to the exterior, are low. To solve the problem, the embodiment of the invention provides a switch circuit device, wherein protecting elements are connected by disposing two electrode pads, for connection to a single control terminal, on a chip and positioning the electrode pads near the common input terminal pad I and an output terminal pad O1 or O2.
    Type: Application
    Filed: February 20, 2004
    Publication date: November 11, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Toshikazu Hirai
  • Publication number: 20040211990
    Abstract: A semiconductor switching device includes a plurality of metal layers. At least one of the metal layers forming a Schottky junction with a semi-insulating substrate or an insulating layer on a substrate. The device also includes an impurity diffusion region, and a high-concentration impurity region formed between two of the metal layers or between one of the metal layers and the impurity diffusion region so as to suppress expansion of a depletion layer from the corresponding metal layer.
    Type: Application
    Filed: October 14, 2003
    Publication date: October 28, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Patent number: 6787871
    Abstract: An integrated Schottky barrier diode chip includes a compound semiconductor substrate, a plurality of Schottky barrier diodes formed on the substrate and an insulating region formed on the substrate by an on implantation. The insulating region electrically separates a portion of a diode at a cathode voltage from a portion of the diode at an anode voltage. Because of the absence of a polyimide layer and trench structures, this planar device configuration results in simpler manufacturing method and improved device characteristics.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: September 7, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Patent number: 6777277
    Abstract: A Schottky barrier diode has a Schottky contact region formed in an n epitaxial layer disposed on a GaAs substrate and an ohmic electrode surrounding the Schottky contact region. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. An insulating region is formed through the n epitaxial layer so that an anode bonding pad is isolated form other elements of the device at a cathode voltage. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: August 17, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara
  • Publication number: 20040130380
    Abstract: Since a 5 GHz-band broadband has a frequency twice that of 2.4 GHz, the parasitic capacitance greatly influences deterioration in isolation of a switching device used in this frequency region. Therefore, to improve isolation, a shunt FET is added to the device. The switching device also includes a protecting element that has a first n+-type region, an insulating region and a second n+-type region. This protecting element is connected in parallel between two electrodes of the shunt FET. Since electrostatic charges are discharged between the first and second n+-type regions, the electrostatic energy reaching an operation region of the shunt FET can be reduced without an increase in parasitic capacitance.
    Type: Application
    Filed: October 17, 2003
    Publication date: July 8, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Patent number: 6727559
    Abstract: A local oscillation FET has a source connecting pad, a drain connecting pad and a gate connecting pad. The source connecting pad occupies one corner of a substrate, and the drain and gate connecting pads are placed at the neighboring corners so that the three connecting pads form an L shape on the substrate. As a modification to this configuration, another source connecting pad is placed at the remaining corner of the substrate so that the drain and gate connecting pads are shielded from each other by the two source connecting pads. These device configurations contribute to size reduction of the local oscillation FET.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: April 27, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Masahiro Uekawa, Koichi Hirata, Mikito Sakakibara
  • Publication number: 20040021156
    Abstract: Posts are disposed at the surroundings of an FET and a shield metal supported by the posts is placed above the FET to create a void between the FET and the shield metal. Since the separation between the FET and the shield metal is small, the resin does not enter the void. A resin layer cover the shield metal. The shield metal is connected to an electrode pad that receives a DC control signal. Although high frequency signals that are applied to the FET may leak between the source and drain electrodes of the FET through the resin layer covering the FET even when the FET is switched off, the void and the shield metal prevent such signal leakage.
    Type: Application
    Filed: April 16, 2003
    Publication date: February 5, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara
  • Publication number: 20040017701
    Abstract: A semiconductor switching circuit device includes a field effect transistor having a source electrode, a gate electrode and a drain electrode, a first electrode pad connected to the source electrode or the drain electrode, and a second electrode pad connected to the source electrode or the drain electrode which is not connected to the first electrode pad. The device also includes a third electrode pad receiving a DC voltage and applying the DC voltage to the field effect transistor, a first insulating layer covering the field effect transistor, a metal layer disposed above the first insulating layer and connected to the third electrode pad, and a second insulating layer disposed on the metal layer. The third electrode pad may be a control terminal pad, a ground terminal pad or a terminal pad receiving a constant DC power voltage. The metal layer may be a flat sheet, a lattice or a comb-like structure.
    Type: Application
    Filed: April 16, 2003
    Publication date: January 29, 2004
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Tetsuro Asano, Mikito Sakakibara
  • Patent number: 6682968
    Abstract: A Schottky barrier diode has a Schottky electrode formed on an operation region of a GaAs substrate and an ohmic electrode surrounding the Schottky electrode. The ohmic electrode is disposed directly on an impurity-implanted region formed on the substrate. A nitride film insulates the ohmic electrode from a wiring layer connected to the Schottky electrode crossing over the ohmic electrode. The planar configuration of this device does not include the conventional polyimide layer, and thus has a better high frequency characteristics than conventional devices.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: January 27, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Katsuaki Onoda, Yoshibumi Nakajima, Shigeyuki Murai, Hisaaki Tominaga, Koichi Hirata, Mikito Sakakibara, Hidetoshi Ishihara