Patents by Inventor Eung San Cho

Eung San Cho 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).

  • Patent number: 8901742
    Abstract: According to an exemplary embodiment, a monolithic power converter package includes a monolithic die over a substrate, the monolithic die integrating a driver integrated circuit (IC) with a control power transistor and a sync power transistor connected in a half-bridge. The high side power input and a power output of the half-bridge each are disposed on a top surface of the monolithic die. The high side power input is electrically coupled to the substrate through a high side power connection. The power output is electrically coupled to the substrate through a power output connection. The low side power input of the half-bridge comprises a plurality of through substrate vias that extend through the monolithic die to electrically connect a low side power pad to the monolithic die.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: December 2, 2014
    Assignee: International Rectifier Corporation
    Inventors: Eung San Cho, Dean Fernando, Tim Philips, Dan Clavette
  • Patent number: 8896107
    Abstract: One exemplary disclosed embodiment comprises a high power semiconductor package configured as a buck converter having a control transistor, a sync transistor, a driver integrated circuit (IC) for driving the control and sync transistors, and a conductive clip electrically coupling a sync drain of the sync transistor to a first leadframe pad of the package, wherein the first leadframe pad of the package is electrically coupled to a control source of the control transistor using a wirebond. The conductive clip provides an efficient connection between the control source and the sync drain by direct mechanical connection and large surface area conduction. A sync source is electrically and mechanically coupled to a second leadframe pad providing a high current carrying capability, and high reliability. The resulting package has significantly reduced electrical resistance, form factor, complexity, and cost when compared to conventional packaging methods using wirebonds for transistor interconnections.
    Type: Grant
    Filed: April 27, 2011
    Date of Patent: November 25, 2014
    Assignee: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah
  • Publication number: 20140203419
    Abstract: According to an exemplary embodiment, a stacked half-bridge package includes a control transistor having a control drain for connection to a high voltage input, a control source coupled to a common conductive clip, and a control gate for being driven by a driver IC. The stacked half-bridge package also includes a sync transistor having a sync drain for connection to the common conductive clip, a sync source coupled to a low voltage input, and a sync gate for being driven by the driver IC. The control and sync transistors are stacked on opposite sides of the common conductive clip with the common conductive clip electrically and mechanically coupling the control source with the sync drain, where the common conductive clip has a conductive leg for providing electrical and mechanical connection to an output terminal leadframe.
    Type: Application
    Filed: March 21, 2014
    Publication date: July 24, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
  • Publication number: 20140191337
    Abstract: According to an exemplary embodiment, a stacked half-bridge package includes a control transistor having a control drain for connection to a high voltage input, a control source coupled to an output terminal, and a control gate for being driven by a driver IC. The stacked half-bridge package also includes a sync transistor having a sync drain for connection to the output terminal, a sync source coupled to a low voltage input, and a sync gate for being driven by the driver IC. A current carrying layer is situated on the sync drain; the control transistor and the sync transistor being stacked on one another, where the current carrying layer provides a high current connection between the sync drain and the control source.
    Type: Application
    Filed: March 13, 2014
    Publication date: July 10, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
  • Publication number: 20140175630
    Abstract: One exemplary disclosed embodiment comprises a high power semiconductor package configured as a buck converter having a control transistor and a sync transistor disposed on a common leadframe pad, a driver integrated circuit (IC) for driving the control and sync transistors, and conductive clips electrically coupling the top surfaces of the transistors to substrate pads such as leadframe pads. In this manner, the leadframe and the conductive clips provide efficient grounding or current conduction by direct mechanical connection and large surface area conduction, thereby enabling a package with significantly reduced electrical resistance, form factor, complexity, and cost when compared to conventional packaging methods using wirebonds for transistor interconnections.
    Type: Application
    Filed: February 27, 2014
    Publication date: June 26, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah
  • Patent number: 8749034
    Abstract: One exemplary disclosed embodiment comprises a high power semiconductor package configured as a buck converter having a sync transistor with a top surface having a drain, a flip chip driver integrated circuit (IC) having an integrated control transistor, the flip chip driver IC driving the sync and control transistors, and a conductive clip electrically coupling the drain of the sync transistor to a common portion of the leadframe shared with a control source of the control transistor. In this manner, the leadframe and the conductive clip provide efficient current conduction by direct mechanical connection and large surface area conduction, significantly reducing package electrical resistance, form factor, complexity, and cost compared to conventional packages.
    Type: Grant
    Filed: April 27, 2011
    Date of Patent: June 10, 2014
    Assignee: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah
  • Publication number: 20140110796
    Abstract: In one implementation, a semiconductor package includes a control conductive carrier having a die side and an opposite input/output (I/O) side connecting the semiconductor package to a mounting surface. The semiconductor package also includes a control FET of a power converter switching stage having a control drain attached to the die side of the control conductive carrier. The control conductive carrier is configured to sink heat produced by the control FET into the mounting surface. The semiconductor package includes a sync conductive carrier having another die side and another opposite I/O side connecting the semiconductor package to the mounting surface, and a sync FET of the power converter switching stage having a sync source attached to the die side of the sync conductive carrier.
    Type: Application
    Filed: September 10, 2013
    Publication date: April 24, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Andrew N. Sawle, Mark Pavier, Daniel Cutler
  • Publication number: 20140110863
    Abstract: In one implementation, a semiconductor package includes a control conductive carrier having a die side and an opposite input/output (I/O) side connecting the semiconductor package to a mounting surface. The semiconductor package also includes a control FET of a power converter switching stage attached to the die side of the control conductive carrier, and a driver integrated circuit (IC) for driving the control FET. The driver IC is situated above the control FET and is electrically coupled to the control FET by at least one conductive buildup layer formed over the control conductive carrier.
    Type: Application
    Filed: September 10, 2013
    Publication date: April 24, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Andrew N. Sawle, Mark Pavier, Daniel Cutler
  • Publication number: 20140110776
    Abstract: In one implementation, a semiconductor package including conductive carrier coupled power switches includes a first vertical FET in a first active die having a first source and a first gate on a source side of the first active die and a first drain on a drain side of the first active die. The semiconductor package also includes a second vertical FET in a second active die having a second source and a second gate on a source side of the second active die and a second drain on a drain side of the second active die. The semiconductor package includes a conductive carrier attached to the source side of the first active die and to the drain side of the second active die, the conductive carrier coupling the first source to the second drain.
    Type: Application
    Filed: September 9, 2013
    Publication date: April 24, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Andrew N. Sawle, Mark Pavier, Daniel Cutler
  • Publication number: 20140110788
    Abstract: In one implementation, a semiconductor package includes a top-drain vertical FET in a first active die, a source of the top-drain vertical FET situated on a source side of the first active die and a drain and a gate of the top-drain vertical FET situated on a drain side of the first active die. The semiconductor package also includes a bottom-drain vertical FET in a second active die, a source and a gate of the bottom-drain vertical FET situated on a source side of the second active die and a drain of the bottom-drain vertical FET situated on a drain side of the second active die. The semiconductor package includes a conductive carrier attached to the source side of the first active die and to the drain side of the second active die, the conductive carrier coupling the source of the top-drain vertical FET to the drain of the bottom-drain vertical FET.
    Type: Application
    Filed: September 9, 2013
    Publication date: April 24, 2014
    Applicant: International Rectifier Corporation
    Inventors: Eung San Cho, Andrew N. Sawle, Mark Pavier, Daniel Cutler
  • Patent number: 8680627
    Abstract: According to an exemplary embodiment, a stacked half-bridge package includes a control transistor having a control drain for connection to a high voltage input, a control source coupled to a common conductive clip, and a control gate for being driven by a driver IC. The stacked half-bridge package also includes a sync transistor having a sync drain for connection to the common conductive clip, a sync source coupled to a low voltage input, and a sync gate for being driven by the driver IC. The control and sync transistors are stacked on opposite sides of the common conductive clip with the common conductive clip electrically and mechanically coupling the control source with the sync drain, where the common conductive clip has a conductive leg for providing electrical and mechanical connection to an output terminal leadframe.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: March 25, 2014
    Assignee: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
  • Patent number: 8680661
    Abstract: Some exemplary embodiments of a direct contact leadless package and related structure and method, especially suitable for packaging high current semiconductor devices, have been disclosed. One exemplary structure comprises a first contact lead frame portion, a paddle portion, and an extended contact lead frame portion held together by a mold compound. A first semiconductor device is attached to a top side of the paddle portion and is enclosed by said mold compound, while a second semiconductor device is attached to a bottom side of said paddle portion and is in electrical contact with said the first semiconductor device. The extended contact lead frame portion is in direct electrical contact with the second semiconductor device without using a bond wire. Alternative exemplary embodiments may include additional extended lead frame portions, paddle portions, and semiconductor devices in various configurations.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: March 25, 2014
    Assignee: International Rectifier Corporation
    Inventor: Eung San Cho
  • Patent number: 8674497
    Abstract: According to an exemplary embodiment, a stacked half-bridge package includes a control transistor having a control drain for connection to a high voltage input, a control source coupled to an output terminal, and a control gate for being driven by a driver IC. The stacked half-bridge package also includes a sync transistor having a sync drain for connection to the output terminal, a sync source coupled to a low voltage input, and a sync gate for being driven by the driver IC. A current carrying layer is situated on the sync drain; the control transistor and the sync transistor being stacked on one another, where the current carrying layer provides a high current connection between the sync drain and the control source.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: March 18, 2014
    Assignee: International Business Machines Corporation
    Inventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
  • Patent number: 8664754
    Abstract: One exemplary disclosed embodiment comprises a high power semiconductor package configured as a buck converter having a control transistor and a sync transistor disposed on a common leadframe pad, a driver integrated circuit (IC) for driving the control and sync transistors, and conductive clips electrically coupling the top surfaces of the transistors to substrate pads such as leadframe pads. In this manner, the leadframe and the conductive clips provide efficient grounding or current conduction by direct mechanical connection and large surface area conduction, thereby enabling a package with significantly reduced electrical resistance, form factor, complexity, and cost when compared to conventional packaging methods using wirebonds for transistor interconnections.
    Type: Grant
    Filed: April 27, 2011
    Date of Patent: March 4, 2014
    Assignee: International Rectifier Corporation
    Inventors: Eung San Cho, Chuan Cheah
  • Publication number: 20140001614
    Abstract: One exemplary disclosed embodiment comprises a semiconductor package including an inside pad, a transistor, and a conductive clip coupled to the inside pad and a terminal of the transistor. A top surface of the conductive clip is substantially exposed at the top of the package, and a side surface of the conductive clip is exposed at a side of the package. By supporting the semiconductor package on an outside pad during the fabrication process and by removing the outside pad during singulation, the conductive clip may be kept substantially parallel and in alignment with the package substrate while optimizing the package form factor compared to conventional packages. The exposed top surface of the conductive clip may be further attached to a heat sink for enhanced thermal dissipation.
    Type: Application
    Filed: September 6, 2013
    Publication date: January 2, 2014
    Applicant: International Rectifier Corporation
    Inventor: Eung San Cho
  • Patent number: 8614503
    Abstract: One exemplary disclosed embodiment comprises a semiconductor package including multiple transistors having a common drain coupled to an exposed conductive clip. A driver integrated circuit (IC) may control the transistors for various power applications. By exposing a top surface of the exposed conductive clip outside of a mold compound of the package, enhanced thermal performance is provided. Additionally, the conductive clip provides a short distance, high current carrying route between transistors of the package, providing higher electrical performance and reduced form factor compared to conventional designs with individually packaged transistors.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: December 24, 2013
    Assignee: International Rectifier Corporation
    Inventor: Eung San Cho
  • Publication number: 20130337611
    Abstract: One exemplary disclosed embodiment comprises a semiconductor package including an inside pad, a transistor, and a conductive clip coupled to the inside pad and a terminal of the transistor. A top surface of the conductive clip is substantially exposed at the top of the package, and a side surface of the conductive clip is exposed at a side of the package. By supporting the semiconductor package on an outside pad during the fabrication process and by removing the outside pad during singulation, the conductive clip may be kept substantially parallel and in alignment with the package substrate while optimizing the package form factor compared to conventional packages. The exposed top surface of the conductive clip may be further attached to a heat sink for enhanced thermal dissipation.
    Type: Application
    Filed: August 17, 2013
    Publication date: December 19, 2013
    Applicant: International Rectifier Corporation
    Inventor: Eung San Cho
  • Patent number: 8575736
    Abstract: Some exemplary embodiments of an advanced direct contact leadless package and related structure and method, especially suitable for packaging high current semiconductor devices, have been disclosed. One exemplary structure comprises a mold compound enclosing a first contact lead frame portion, a paddle portion, and an extended contact lead frame portion held together by a mold compound. A first semiconductor device is attached on top of the lead frame portions as a flip chip, while a second semiconductor device is attached to a bottom side of said paddle portion and is in electrical contact with said the first semiconductor device. The extended contact lead frame portion is in direct electrical contact with the second semiconductor device without using a bond wire. Alternative exemplary embodiments may include additional extended lead frame portions, paddle portions, and semiconductor devices in various configurations.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: November 5, 2013
    Assignee: International Rectifier Corporation
    Inventor: Eung San Cho
  • Patent number: 8575737
    Abstract: Some exemplary embodiments of an advanced direct contact leadless package and related structure and method, especially suitable for packaging high current semiconductor devices, have been disclosed. One exemplary structure comprises a mold compound enclosing a first contact lead frame portion, a paddle portion, and an extended contact lead frame portion held together by a mold compound. A first semiconductor device is attached on top of the lead frame portions as a flip chip, while a second semiconductor device is attached to a bottom side of said paddle portion and is in electrical contact with said the first semiconductor device. The extended contact lead frame portion is in direct electrical contact with the second semiconductor device without using a bond wire. Alternative exemplary embodiments may include additional extended lead frame portions, paddle portions, and semiconductor devices in various configurations.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: November 5, 2013
    Assignee: International Rectifier Corporation
    Inventor: Eung San Cho
  • Publication number: 20130256905
    Abstract: According to an exemplary embodiment, a monolithic power converter package includes a monolithic die over a substrate, the monolithic die integrating a driver integrated circuit (IC) with a control power transistor and a sync power transistor connected in a half-bridge. The high side power input and a power output of the half-bridge each are disposed on a top surface of the monolithic die. The high side power input is electrically coupled to the substrate through a high side power connection. The power output is electrically coupled to the substrate through a power output connection. The low side power input of the half-bridge comprises a plurality of through substrate vias that extend through the monolithic die to electrically connect a low side power pad to the monolithic die.
    Type: Application
    Filed: October 19, 2012
    Publication date: October 3, 2013
    Applicant: INTERNATIONAL RECTIFIER CORPORATION
    Inventors: Eung San Cho, Dean Fernando, Tim Philips, Dan Clavette