Patents Assigned to Alpha and Omega Semiconductor Incorporated
  • Publication number: 20160056096
    Abstract: A preparation method for a power semiconductor device includes: providing a lead frame containing a plurality of chip mounting units, one side edge of a die paddle of each chip mounting unit is bent and extended upwardly and one lead connects to the bent side edge of the die paddle and extends in an opposite direction from the die paddle; attaching a semiconductor chip to the top surface of the die paddle; forming metal bumps on each electrode at the front of the semiconductor chip with a top end of each metal bump protruding out of a plane of the top surface of the lead; heating the metal bump and pressing a top end of each metal bump by a pressing plate forming a flat top end surface that is flush with the top surface of the lead; and cutting the lead frame to separate individual chip mounting units.
    Type: Application
    Filed: October 30, 2015
    Publication date: February 25, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu
  • Patent number: 9269805
    Abstract: Aspects of the present disclosure describe a trench MOSFET with a channel length that may be controlled by counterdoping the body-drain junction to form a straggle region adjacent to the trenches. The channel length is defined between the straggle region at the bottom and a source region at the top. Both of the straggle region and the source region are of the same conductivity type though they may be different ion species. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: February 23, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Sik Lui
  • Patent number: 9269699
    Abstract: The present invention discloses a new embedded package comprising: a pre-mold lead frame with a plurality of chips attached thereon, where the molding material fills the voids of the lead frame, so that the lead frame is entirely solid; a plurality of pins arranged around the lead frame; a metal clip attached on and electrically connecting the chips together; first laminate layer which covers the chips, the lead frame, a metal clip and pins; conductive plug and extension formed to connect an electrode of a chip to a corresponding pin or to connect the chips together. The new embedded package of the invention with a three-dimensional stack capacity improves the thickness, thermal and electrical properties and the flexible power and logic hybrid design.
    Type: Grant
    Filed: May 9, 2014
    Date of Patent: February 23, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Zhiqiang Niu, Hua Pan, Ming-Chen Lu, Yueh-Se Ho, Jun Lu
  • Patent number: 9265121
    Abstract: An efficient, cost effective power driver for OLED panels is configured with a small BOM without compromising the display quality. The power driver adopts only one Inverting Buck-Boost Converter (IBBC) to regulate the necessary output voltage for the OLED panel load. The output voltage to drive the OLED panel load is supplied by the IBBC and the positive input of the OLED panel is tied into the input power supply of VIN directly without any switch. A DC-DC converter is provided to generate a reference ground and drive the associated control circuits. The input DC voltage VIN is utilized as a reference voltage for both the IBBC and the DC-DC converter.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: February 16, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Gilbert S. Lee
  • Patent number: 9252264
    Abstract: Aspects of the present disclosure describe a high density trench-based power MOSFETs with self-aligned source contacts and methods for making such devices. The source contacts are self-aligned with spacers and the active devices may have a two-step gate oxide. A lower portion may have a thickness that is larger than the thickness of an upper portion of the gate oxide. The MOSFETS also may include a depletable shield in a lower portion of the substrate. The depletable shield may be configured such that during a high drain bias the shield substantially depletes. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Hamza Yilmaz, Sik Lui, Daniel Ng
  • Patent number: 9252239
    Abstract: This invention discloses semiconductor power device that includes a plurality of top electrical terminals disposed near a top surface of a semiconductor substrate. Each and every one of the top electrical terminals comprises a terminal contact layer formed as a silicide contact layer near the top surface of the semiconductor substrate. The trench gates of the semiconductor power device are opened from the top surface of the semiconductor substrate and each and every one of the trench gates comprises the silicide layer configured as a recessed silicide contact layer disposed on top of every on of the trench gates slightly below a top surface of the semiconductor substrate surround the trench gate.
    Type: Grant
    Filed: May 31, 2014
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, John Chen, Daniel Ng, Wenjun Li
  • Patent number: 9252265
    Abstract: A method for fabricating a semiconductor device includes forming a plurality of trenches using a first mask. The trenches include source pickup trenches located in outside a termination area and between two adjacent active areas. First and second conductive regions separated by an intermediate dielectric region are formed using a second mask. A first electrical contact to the first conductive region and a second electrical contact to the second conductive region are formed using a third mask and forming a source metal region. Contacts to a gate metal region are formed using a fourth mask. A semiconductor device includes a source pickup contact located outside a termination region and outside an active region of the device.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: February 2, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hong Chang, Yi Su, Wenjun Li, Limin Weng, Gary Chen, Jongoh Kim, John Chen
  • Patent number: 9245861
    Abstract: A wafer process for MCSP comprises: depositing a metal bump on bonding pads of chips; forming a first packaging layer at front surface of wafer covering metal bumps while forming an un-covered ring at the edge of wafer to expose the ends of each scribe line located between two adjacent chips; thinning first packaging layer to expose metal bumps; grinding back surface of wafer to form a recessed space and a support ring at the edge of the wafer; depositing a metal seed layer and a thick metal layer at bottom surface of wafer in recessed space in a sequence; cutting off the edge portion of wafer; and separating individual chips from wafer by cutting through first packaging layer, the wafer and the metal seed and metal layers along the scribe line.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: January 26, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Yan Xun Xue, Hamza Yilmaz, Yueh-Se Ho, Jun Lu, Zhiqiang Niu, Guo Feng Lian, Hong Xia Fu, Yu Ping Gong
  • Patent number: 9246347
    Abstract: A semiconductor die with integrated MOSFET and diode-connected enhancement mode JFET is disclosed. The MOSFET-JFET die includes common semiconductor substrate region (CSSR) of type-1 conductivity. A MOSFET device and a diode-connected enhancement mode JFET (DCE-JFET) device are located upon CSSR. The DCE-JFET device has the CSSR as its DCE-JFET drain. At least two DCE-JFET gate regions of type-2 conductivity located upon the DCE-JFET drain and laterally separated from each other with a DCE-JFET gate spacing. At least a DCE-JFET source of type-1 conductivity located upon the CSSR and between the DCE-JFET gates. A top DCE-JFET electrode, located atop and in contact with the DCE-JFET gate regions and DCE-JFET source regions. When properly configured, the DCE-JFET simultaneously exhibits a forward voltage Vf substantially lower than that of a PN junction diode while the reverse leakage current can be made comparable to that of a PN junction diode.
    Type: Grant
    Filed: December 10, 2013
    Date of Patent: January 26, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sik Lui, Wei Wang
  • Patent number: 9245949
    Abstract: Semiconductor devices are formed using a thin epitaxial layer (nanotube) formed on sidewalls of dielectric-filled trenches. In one embodiment, a semiconductor device is formed in a semiconductor layer on a semiconductor substrate of opposite conductivity type and having trenches formed therein where the trenches extend from the top surface to the bottom surface of the semiconductor layer. The semiconductor device includes a first epitaxial layer formed on sidewalls of the trenches where the first epitaxial layer is substantially charge balanced with adjacent semiconductor regions. In another embodiment, a semiconductor device is formed in a first semiconductor layer having trenches and mesas formed thereon where the trenches extend from the top surface to the bottom surface of the first semiconductor layer. The semiconductor device includes semiconductor regions formed on the bottom surface of the mesas of the first semiconductor layer.
    Type: Grant
    Filed: December 4, 2014
    Date of Patent: January 26, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Hamza Yilmaz, Xiaobin Wang, Anup Bhalla, John Chen, Hong Chang
  • Publication number: 20160005853
    Abstract: A semiconductor device includes a plurality of trenches including active gate trenches in an active area and gate runner/termination trenches and shield electrode pickup trenches in a termination area outside the active area. The gate runner/termination trenches include one or more trenches that define a mesa located outside an active area. A first conductive region is formed in the plurality of trenches. An intermediate dielectric region and termination protection region are formed in the trenches that define the mesa. A second conductive region is formed in the portion of the trenches that define the mesa. The second conductive region is electrically isolated from the first conductive region by the intermediate dielectric region. A first electrical contact is made to the second conductive regions and a second electrical contact to the first conductive region in the shield electrode pickup trenches. One or more Schottky diodes are formed within the mesa.
    Type: Application
    Filed: June 27, 2014
    Publication date: January 7, 2016
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Yi Su, Daniel Ng, Anup Bhalla, Hong Chang, Jongoh Kim, John Chen
  • Patent number: 9230949
    Abstract: A stacked multi-chip packaging structure comprises a lead frame, a first semiconductor chip mounted on the lead frame, a second semiconductor chip flipped-chip mounted on the lead frame, a metal clip mounted on top of the first and second semiconductor chips and a third semiconductor chip stacked on the metal clip; bonding wires electrically connecting electrodes on the third semiconductor chip to the first and second semiconductor chips and the pins of the lead frame; plastic molding encapsulating the lead frame, the chips and the metal clip.
    Type: Grant
    Filed: March 7, 2015
    Date of Patent: January 5, 2016
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventors: Xiaotian Zhang, Hua Pan, Ming-Chen Lu, Jun Lu, Hamza Yilmaz
  • Patent number: 9230957
    Abstract: Aspects of the present disclosure describe MOSFET devices that have snubber circuits. The snubber circuits comprise one or more resistors with a dynamically controllable resistance that is controlled by changes to a gate and/or drain potentials of the one or more MOSFET structures during switching events.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: January 5, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sik Lui, Ji Pan
  • Patent number: 9231050
    Abstract: This invention discloses a semiconductor power device disposed in a semiconductor substrate and having an active cell area and an edge termination area the edge termination area wherein the edge termination area comprises a superjunction structure having doped semiconductor columns of alternating conductivity types with a charge imbalance between the doped semiconductor columns to generate a saddle junction electric field in the edge termination.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: January 5, 2016
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Lingping Guan, Anup Bhalla, Hamza Yilmaz
  • Patent number: 9224669
    Abstract: A method to provide a wafer level package with increasing contact pad area comprising the steps of forming a first packaging layer on wafer top surface, grinding the wafer back surface and etch through holes, depositing a metal to fill the through holes and covering wafer backside, cutting through the wafer from wafer backside forming a plurality of grooves separating each chip then depositing a second packaging layer filling the grooves and covering the wafer back metal, reducing the first packaging layer thickness to expose the second packaging layer filling the grooves and forming a plurality of contact pads overlaying the first packaging layer thereafter cutting through the second packaging layer in the grooves to form individual package.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: December 29, 2015
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Yan Xun Xue
  • Patent number: 9224679
    Abstract: A method for forming a wafer level chip scale (WLCS) package device with a thick bottom metal comprising the step of attaching a lead frame comprising a plurality of thick bottom metals onto a back metal layer of a semiconductor wafer including a plurality of semiconductor chips having a plurality of bonding pads formed on a front surface of each chip, each thick bottom metal is aligned to a central portion of each chip; a plurality of back side cutting grooves are formed along the scribe lines and filled with a package material, the package material are cut through thus forming a plurality of singulated WLCS package devices.
    Type: Grant
    Filed: September 8, 2014
    Date of Patent: December 29, 2015
    Assignee: ALPHA AND OMEGA SEMICONDUCTOR INCORPORATED
    Inventor: Yan Xun Xue
  • Patent number: 9224852
    Abstract: A corner layout for a semiconductor device that maximizes the breakdown voltage is disclosed. The device includes first and second subsets of the striped cell arrays. The ends of each striped cell in the first array is spaced a uniform distance from the nearest termination device structure. In the second subset, the ends of striped cells proximate a corner of the active cell region are configured to maximize breakdown voltage by spacing the ends of each striped cell a non-uniform distance from the nearest termination device structure. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: December 29, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Lingpeng Guan, Anup Bhalla
  • Patent number: 9219003
    Abstract: An oxide termination semiconductor device may comprise a plurality of gate trenches, a gate runner, and an insulator termination trench. The gate trenches are located in an active region. Each gate trench includes a conductive gate electrode. The insulator termination trench is located in a termination region that surrounds the active region. The insulator termination trench is filled with an insulator material to form an insulator termination for the semiconductor device. Source and body regions inside the active region are at source potential and source and body regions outside the isolation trench are at drain potential. The device can be made using a three-mask or four-mask process.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: December 22, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sik Lui, Anup Bhalla
  • Patent number: 9214417
    Abstract: A combined packaged power semiconductor device includes flipped top source low-side MOSFET electrically connected to top surface of a die paddle, first metal interconnection plate connecting between bottom drain of a high-side MOSFET or top source of a flipped high-side MOSFET to bottom drain of the low-side MOSFET, and second metal interconnection plate stacked on top of the high-side MOSFET chip. The high-side, low-side MOSFET and the IC controller can be packaged three-dimensionally reducing the overall size of semiconductor devices and can maximize the chip's size within a package of the same size and improves the performance of the semiconductor devices. The top source of flipped low-side MOSFET is connected to the top surface of the die paddle and thus is grounded through the exposed bottom surface of die paddle, which simplifies the shape of exposed bottom surface of the die paddle and maximizes the area to facilitate heat dissipation.
    Type: Grant
    Filed: February 21, 2014
    Date of Patent: December 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Yueh-Se Ho, Hamza Yilmaz, Yan Xun Xue, Jun Lu
  • Patent number: 9214534
    Abstract: A lateral bipolar transistor with deep emitter and deep collector regions is formed using multiple epitaxial layers of the same conductivity type. Deep emitter and deep collector regions are formed without the use of trenches. Vertically aligned diffusion regions are formed in each epitaxial layer so that the diffusion regions merged into a contiguous diffusion region after annealing to function as emitter or collector or isolation structures. In another embodiment, a lateral trench PNP bipolar transistor is formed using trench emitter and trench collector regions. In yet another embodiment, a lateral PNP bipolar transistor with a merged LDMOS transistor is formed to achieve high performance.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: December 15, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Shekar Mallikarjunaswamy, Francois Hebert