Patents by Inventor Chuan Cheah
Chuan Cheah 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).
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Publication number: 20150279821Abstract: 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: ApplicationFiled: May 27, 2015Publication date: October 1, 2015Inventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
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Patent number: 9142503Abstract: Some exemplary embodiments of high voltage cascoded III-nitride semiconductor package utilizing clips on a package support surface have been disclosed. One exemplary embodiment comprises a III-nitride transistor attached to a package support surface and having an anode of a diode stacked over a source of the III-nitride transistor, a first conductive clip coupled to a gate of the III-nitride transistor and the anode of the diode, and a second conductive clip coupled to a drain of the III-nitride transistor. The conductive clips are connected to the package support surface and expose respective flat portions that are surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since a low cost printed circuit board (PCB) may be utilized for the package support surface, expensive leadless fabrication processes may be avoided for cost effective manufacturing.Type: GrantFiled: July 16, 2014Date of Patent: September 22, 2015Assignee: International Rectifier CorporationInventors: Chuan Cheah, Dae Keun Park
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Patent number: 9105619Abstract: A semiconductor package that includes a semiconductor die and a heat spreader thermally coupled to the semiconductor and disposed at least partially within the molded housing of the package.Type: GrantFiled: February 15, 2013Date of Patent: August 11, 2015Assignee: International Rectifier CorporationInventors: Michael A. Briere, Chuan Cheah, Kunzhong Hu
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Publication number: 20150194369Abstract: 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 leadfirame 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: ApplicationFiled: March 19, 2015Publication date: July 9, 2015Inventors: Eung San Cho, Chuan Cheah
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Patent number: 9048230Abstract: 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: GrantFiled: March 21, 2014Date of Patent: June 2, 2015Assignee: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
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Patent number: 8987883Abstract: 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: GrantFiled: February 27, 2014Date of Patent: March 24, 2015Assignee: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah
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Publication number: 20150014703Abstract: Some exemplary embodiments of a III-nitride power device including a HEMT with multiple interconnect metal layers and a solderable front metal structure using solder bars for external circuit connections have been disclosed. The solderable front metal structure may comprise a tri-metal such as TiNiAg, and may be configured to expose source and drain contacts of the HEMT as alternating elongated digits or bars. Additionally, a single package may integrate multiple such HEMTs wherein the front metal structures expose alternating interdigitated source and drain contacts, which may be advantageous for DC-DC power conversion circuit designs using III-nitride devices. By using solder bars for external circuit connections, lateral conduction is enabled, thereby advantageously reducing device Rdson.Type: ApplicationFiled: October 2, 2014Publication date: January 15, 2015Inventors: Chuan Cheah, Michael A. Briere
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Patent number: 8896107Abstract: 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: GrantFiled: April 27, 2011Date of Patent: November 25, 2014Assignee: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah
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Publication number: 20140327014Abstract: Some exemplary embodiments of high voltage cascoded III-nitride semiconductor package utilizing clips on a package support surface have been disclosed. One exemplary embodiment comprises a III-nitride transistor attached to a package support surface and having an anode of a diode stacked over a source of the III-nitride transistor, a first conductive clip coupled to a gate of the III-nitride transistor and the anode of the diode, and a second conductive clip coupled to a drain of the III-nitride transistor. The conductive clips are connected to the package support surface and expose respective flat portions that are surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since a low cost printed circuit board (PCB) may be utilized for the package support surface, expensive leadless fabrication processes may be avoided for cost effective manufacturing.Type: ApplicationFiled: July 16, 2014Publication date: November 6, 2014Inventors: Chuan Cheah, Dae Keun Park
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Patent number: 8853707Abstract: Some exemplary embodiments of high voltage cascaded III-nitride semiconductor package with an etched leadframe have been disclosed. One exemplary embodiment comprises a III-nitride transistor having an anode of a diode stacked over a source of the III-nitride transistor, and a leadframe that is etched to form a first leadframe paddle portion coupled to a gate of the III-nitride transistor and the anode of the diode, and a second leadframe paddle portion coupled to a drain of the III-nitride transistor. The leadframe paddle portions enable the package to be surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since multiple packages may be assembled at a time, high integration and cost savings may be achieved compared to conventional methods requiring individual package processing and externally sourced parts.Type: GrantFiled: February 1, 2012Date of Patent: October 7, 2014Assignee: International Rectifier CorporationInventors: Chuan Cheah, Dae Keun Park
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Patent number: 8853706Abstract: Some exemplary embodiments of high voltage cascoded III-nitride semiconductor package with a stamped leadframe have been disclosed. One exemplary embodiment comprises a III-nitride transistor having an anode of a diode stacked atop a source of the III-nitride transistor, and a stamped leadframe comprising a first bent lead coupled to a gate of the III-nitride transistor and the anode of the diode, and a second bent lead coupled to a drain of the III-nitride transistor. The bent leads expose respective flat portions that are surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since multiple packages may be assembled at a time, high integration and cost savings may be achieved compared to conventional methods requiring individual package processing and externally sourced parts.Type: GrantFiled: February 1, 2012Date of Patent: October 7, 2014Assignee: International Rectifier CorporationInventors: Chuan Cheah, Dae Keun Park
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Patent number: 8853744Abstract: Some exemplary embodiments of a III-nitride power device including a HEMT with multiple interconnect metal layers and a solderable front metal structure using solder bars for external circuit connections have been disclosed. The solderable front metal structure may comprise a tri-metal such as TiNiAg, and may be configured to expose source and drain contacts of the HEMT as alternating elongated digits or bars. Additionally, a single package may integrate multiple such HEMTs wherein the front metal structures expose alternating interdigitated source and drain contacts, which may be advantageous for DC-DC power conversion circuit designs using III-nitride devices. By using solder bars for external circuit connections, lateral conduction is enabled, thereby advantageously reducing device Rdson.Type: GrantFiled: March 14, 2013Date of Patent: October 7, 2014Assignee: International Rectifier CorporationInventors: Chuan Cheah, Michael A. Briere
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Patent number: 8811030Abstract: A circuit package includes: electronic circuitry, electrically conductive material forming multiple leads, and multiple connections between the electronic circuitry and the multiple leads. A portion of the electrically conductive material associated with the multiple leads (e.g., low impedance leads supporting high current throughput) is removed to accommodate placement of the electronic circuitry. Each of the multiple leads can support high current. The multiple connections between the, the multiple leads provide connectivity between circuit nodes on the electronic circuitry and pads disposed on a planar surface of the electronic circuit package.Type: GrantFiled: November 30, 2011Date of Patent: August 19, 2014Assignee: International Rectifier CorporationInventors: Timothy Phillips, Danny Clavette, EungSan Cho, Chuan Cheah
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Patent number: 8790965Abstract: Some exemplary embodiments of high voltage cascoded III-nitride semiconductor package utilizing clips on a package support surface have been disclosed. One exemplary embodiment comprises a III-nitride transistor attached to a package support surface and having an anode of a diode stacked over a source of the III-nitride transistor, a first conductive clip coupled to a gate of the III-nitride transistor and the anode of the diode, and a second conductive clip coupled to a drain of the III-nitride transistor. The conductive clips are connected to the package support surface and expose respective flat portions that are surface mountable. In this manner, reduced package footprint, improved surge current capability, and higher performance may be achieved compared to conventional wire bonded packages. Furthermore, since a low cost printed circuit board (PCB) may be utilized for the package support surface, expensive leadless fabrication processes may be avoided for cost effective manufacturing.Type: GrantFiled: September 26, 2013Date of Patent: July 29, 2014Assignee: International Rectifier CorporationInventors: Chuan Cheah, Dae Keun Park
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Patent number: 8791560Abstract: A GaN die having a plurality of parallel alternating and closely spaced source and drain strips is contacted by parallel coplanar comb-shaped fingers of source and drain pads. A plurality of enlarged area coplanar spaced gate pads having respective fingers contacting the gate contact of the die. The pads may be elements of a lead frame, or conductive areas on an insulation substrate. Other semiconductor die can be mounted on the pads and connected in predetermined circuit arrangements with the GaN die.Type: GrantFiled: July 21, 2011Date of Patent: July 29, 2014Assignee: International Rectifier CorporationInventors: Kunzhong Hu, Chuan Cheah
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Publication number: 20140203419Abstract: 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: ApplicationFiled: March 21, 2014Publication date: July 24, 2014Applicant: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
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Patent number: 8786068Abstract: A circuit package includes: electronic circuitry, electrically conductive material forming multiple leads, and multiple connections between the electronic circuitry and the multiple leads. A portion of the electrically conductive material associated with the multiple leads (e.g., low impedance leads supporting high current throughput) is removed to accommodate placement of the electronic circuitry. Each of the multiple leads can support high current. The multiple connections between the multiple leads provide connectivity between circuit nodes on the electronic circuitry and pads disposed on a planar surface of the electronic circuit package.Type: GrantFiled: November 30, 2011Date of Patent: July 22, 2014Assignee: International Rectifier CorporationInventors: Timothy A. Phillips, Danny Clavette, EungSan Cho, Chuan Cheah
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Publication number: 20140191337Abstract: 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: ApplicationFiled: March 13, 2014Publication date: July 10, 2014Applicant: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah, Andrew N. Sawle
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Publication number: 20140175630Abstract: 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: ApplicationFiled: February 27, 2014Publication date: June 26, 2014Applicant: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah
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Patent number: 8749034Abstract: 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: GrantFiled: April 27, 2011Date of Patent: June 10, 2014Assignee: International Rectifier CorporationInventors: Eung San Cho, Chuan Cheah