Patents by Inventor Lakshminarayan Viswanathan

Lakshminarayan Viswanathan 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: 20220130768
    Abstract: Leadless power amplifier (PA) packages and methods for fabricating leadless PA packages having topside terminations are disclosed. In embodiments, the method includes providing electrically-conductive pillar supports and a base flange. At least a first radio frequency (RF) power die is attached to a die mount surface of the base flange and electrically interconnected with the pillar supports. Pillar contacts are further provided, with the pillar contacts electrically coupled to the pillar supports and projecting therefrom in a package height direction. The first RF power die is enclosed in a package body, which at least partially defines a package topside surface opposite a lower surface of the base flange. Topside input/out terminals are formed, which are accessible from the package topside surface and which are electrically interconnected with the first RF power die through the pillar contacts and the pillar supports.
    Type: Application
    Filed: October 22, 2020
    Publication date: April 28, 2022
    Inventors: Yun Wei, Fernando A. Santos, Lakshminarayan Viswanathan, Scott Duncan Marshall
  • Publication number: 20220068817
    Abstract: A substrate is described with a thermal dissipation structure sintered to thermal vias. In one example, a microelectronic module includes a recess between first and second substrate surfaces. One or more thermal vias extend between the first substrate surface and the interior recess surface, wherein each of the thermal vias has an interior end exposed at the interior recess surface. A sintered metal layer is in the recess and in physical contact with the interior end of the thermal vias and a thermal dissipation structure is in the recess over the sintered metal layer. The thermal dissipation structure is attached to the substrate within the recess by the sintered metal layer, and the thermal dissipation structure is thermally coupled to the thermal vias through the sintered metal layer.
    Type: Application
    Filed: August 31, 2020
    Publication date: March 3, 2022
    Inventors: Lu LI, Lakshminarayan VISWANATHAN, Freek Egbert van Straten
  • Patent number: 11196390
    Abstract: Power amplifier devices and methods for fabricating power amplifier devices containing frontside heat extraction structures are disclosed. In embodiments, the power amplifier device includes a substrate, a radio frequency (RF) power die bonded to a die support surface of the substrate, and a frontside heat extraction structure further attached to the die support surface. The frontside heat extraction structure includes, in turn, a transistor-overlay portion in direct thermal contact with a frontside of the RF power die, a first heatsink coupling portion thermally coupled to a heatsink region of the substrate, and a primary heat extraction path extending from the transistor-overlay portion to the first heatsink coupling portion. The primary heat extraction path promotes conductive heat transfer from the RF power die to the heatsink region and reduce local temperatures within a transistor channel of the RF power die during operation of the power amplifier device.
    Type: Grant
    Filed: April 23, 2020
    Date of Patent: December 7, 2021
    Assignee: NXP USA, Inc.
    Inventors: Edward Christian Mares, Lakshminarayan Viswanathan, David James Dougherty
  • Publication number: 20210336585
    Abstract: Power amplifier devices and methods for fabricating power amplifier devices containing frontside heat extraction structures are disclosed. In embodiments, the power amplifier device includes a substrate, a radio frequency (RF) power die bonded to a die support surface of the substrate, and a frontside heat extraction structure further attached to the die support surface. The frontside heat extraction structure includes, in turn, a transistor-overlay portion in direct thermal contact with a frontside of the RF power die, a first heatsink coupling portion thermally coupled to a heatsink region of the substrate, and a primary heat extraction path extending from the transistor-overlay portion to the first heatsink coupling portion. The primary heat extraction path promotes conductive heat transfer from the RF power die to the heatsink region and reduce local temperatures within a transistor channel of the RF power die during operation of the power amplifier device.
    Type: Application
    Filed: April 23, 2020
    Publication date: October 28, 2021
    Inventors: Edward Christian Mares, Lakshminarayan Viswanathan, David James Dougherty
  • Publication number: 20210328552
    Abstract: Power amplifier modules (PAMs) having topside cooling interfaces are disclosed, as are methods for fabricating such PAMs. In embodiments, the method includes attaching the RF power die to a die support-surface of a module substrate. The RF power die is attached to the module substrate in an inverted orientation such that a frontside of the RF power die faces the module substrate. When attaching the RF power die to the module substrate, a frontside input/output interface of the RF power die is electrically coupled to corresponding substrate interconnect features of the module substrate. The method further includes providing a primary heat extraction path extending from the transistor channel of the RF power die to a topside cooling interface of the PAM in a direction opposite the module substrate.
    Type: Application
    Filed: April 17, 2020
    Publication date: October 21, 2021
    Inventors: Geoffrey Tucker, Lakshminarayan Viswanathan, Jeffrey Kevin Jones, Elie A. Maalouf
  • Patent number: 11128268
    Abstract: Power amplifier (PA) packages containing peripherally-encapsulated dies are provided, as are methods for fabricating such PA packages. In embodiments, a method for fabricating a PA package includes obtaining a die-substrate assembly containing a radio frequency (RF) power die, a package substrate, and a die bond layer. The die bond layer is composed of at least one metallic constituent and electrically couples a backside of the RF power die to the package substrate. A peripheral encapsulant body is formed around the RF power die and covers at least a portion of the die bond layer, while leaving at least a majority of a frontside of the RF power die uncovered. Before or after forming the peripheral encapsulant body, terminals of the PA package are interconnected with the RF power die; and a cover piece is bonded to the die-substrate assembly to enclose a gas-containing cavity within the PA package.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: September 21, 2021
    Assignee: NXP USA, Inc.
    Inventors: Sharan Kishore, Jaynal A. Molla, Lakshminarayan Viswanathan, Tianwei Sun, David James Dougherty
  • Patent number: 10861774
    Abstract: Internally-shielded microelectronic packages having increased resistances to electromagnetic cross-coupling are disclosed, as are methods for fabricating such microelectronic packages. In embodiments, the internally-shielded microelectronic package includes a substrate having a frontside and a longitudinal axis. A first microelectronic device is mounted to the frontside of the substrate, while a second microelectronic device is further mounted to the frontside of the substrate and spaced from the first microelectronic device along the longitudinal axis. An internal shield structure includes or consists of a shield wall, which is positioned between the first and second microelectronic devices as taken along the longitudinal axis. The internal shield structure is at least partially composed of a magnetically-permeable material, which decreases electromagnetic cross-coupling between the first and second microelectronic devices during operation of the internally-shielded microelectronic package.
    Type: Grant
    Filed: March 12, 2020
    Date of Patent: December 8, 2020
    Assignee: NXP USA, Inc.
    Inventors: Audel Sanchez, Lakshminarayan Viswanathan, Vikas Shilimkar, Ramanujam Srinidhi Embar
  • Patent number: 10861764
    Abstract: Microelectronic systems and components having integrated heat dissipation posts are disclosed, as are methods for fabricating such microelectronic systems and components. In various embodiments, the microelectronic system includes a substrate having a frontside, a socket cavity, and inner cavity sidewalls defining the socket cavity. A microelectronic component is seated on the frontside of the substrate such that a heat dissipation post, which projects from the microelectronic component, is received in the socket cavity and separated from the inner cavity sidewalls by a peripheral clearance. The microelectronic system further includes a bond layer contacting the inner cavity sidewalls, contacting an outer peripheral portion of the heat dissipation post, and at least partially filling the peripheral clearance.
    Type: Grant
    Filed: March 7, 2019
    Date of Patent: December 8, 2020
    Assignee: NXP USA, Inc.
    Inventors: Lakshminarayan Viswanathan, Mahesh K. Shah, Lu Li, David Abdo, Geoffrey Tucker, Carl Emil D'Acosta, Jaynal A. Molla, Justin Eugene Poarch, Paul Hart
  • Patent number: 10825747
    Abstract: A method of manufacturing a packaged semiconductor device includes forming an assembly by placing a semiconductor die over a substrate with a die attach material between the semiconductor die and the substrate. A conformal structure which includes a pressure transmissive material contacts at least a portion of a top surface of the semiconductor die. A pressure is applied to the conformal structure and in turn, the pressure is transmitted to the top surface of the semiconductor die by the pressure transmissive material. While the pressure is applied, concurrently encapsulating the assembly with a molding compound and exposing the assembly to a temperature that is sufficient to cause the die attach material to sinter.
    Type: Grant
    Filed: September 20, 2017
    Date of Patent: November 3, 2020
    Assignee: NXP USA, INC.
    Inventors: Li Li, Jaynal A. Molla, Lakshminarayan Viswanathan
  • Publication number: 20200335420
    Abstract: A semiconductor device and a method of manufacturing the same include a die and a planar thermal layer, and a thick-silver layer disposed directly onto a first planar side of the planar thermal layer, as well as a metallurgical die-attach disposed between the thick-silver layer and the die, the metallurgical die-attach directly contacting the thick-silver layer.
    Type: Application
    Filed: June 30, 2020
    Publication date: October 22, 2020
    Inventors: Lakshminarayan Viswanathan, Jaynal A. Molla
  • Publication number: 20200335398
    Abstract: A method of wafer dicing includes singulating dies from a semiconductor wafer. The method further includes depositing a metal layer on back sides of the singulated dies, wherein a portion of the metal layer continues beyond the backs sides of the singulated dies to deposit at least partially on lateral sides of the singulated dies. A packaged die includes a semiconductor die and a metal outer layer deposited on the back side of the semiconductor die and on a portion of the lateral side of the semiconductor die nearest the back side. The packaged die further includes a substrate mounted to the back side of the semiconductor die a die attach material that bonds the substrate to the metal outer layer deposited on the semiconductor die, wherein the metal outer layer and the die attach material surround the back edge of the semiconductor die.
    Type: Application
    Filed: July 3, 2020
    Publication date: October 22, 2020
    Inventors: Jaynal A. Molla, Lakshminarayan Viswanathan, David Abdo, Colby Greg Rampley, Fernando A. Santos
  • Publication number: 20200328721
    Abstract: Embodiments of Doherty Power Amplifier (PA) and other PA packages are provided, as are systems including PA packages. In embodiments, the PA package includes a package body having a longitudinal axis, a first group of input-side leads projecting from a first side of the package body and having an intra-group lead spacing, and a first group of output-side leads projecting from a second side of the package body and also having the intra-group lead spacing. A first carrier input lead projects from the first package body side and is spaced from the first group of input-side leads by an input-side isolation gap, which has a width exceeding the intra-group lead spacing. Similarly, a first carrier output lead projects from the second package body side, is laterally aligned with the first carrier input lead, and is separated from the first group of output-side leads by an output-side isolation gap.
    Type: Application
    Filed: March 26, 2020
    Publication date: October 15, 2020
    Inventors: Jean-Christophe Nanan, David James Dougherty, Scott Duncan Marshall, Lakshminarayan Viswanathan, Xavier Hue
  • Patent number: 10806021
    Abstract: A packaged microelectronic component includes a substrate and a semiconductor die coupled to a top surface of the substrate. A method of attaching the packaged microelectronic component to a secondary structure entails applying a metal particle-containing material to at least one of a bottom surface of the substrate and a mounting surface of the secondary structure. The packaged microelectronic component and the secondary structure are arranged in a stacked relationship with the metal particle-containing material disposed between the bottom surface and the mounting surface. A low temperature sintering process is performed at a maximum process temperature less than a melt point of the metal particles to transform the metal particle-containing material into a sintered bond layer joining the packaged microelectronic component and the secondary structure. In an embodiment, the substrate may be a heat sink for the packaged microelectronic component and the secondary structure may be a printed circuit board.
    Type: Grant
    Filed: July 16, 2019
    Date of Patent: October 13, 2020
    Assignee: NXP USA, Inc.
    Inventors: Lakshminarayan Viswanathan, Lu Li, Mahesh K. Shah, Paul Richard Hart
  • Patent number: 10785862
    Abstract: Methods for producing high thermal performance microelectronic modules containing sinter-bonded heat dissipation structures. In one embodiment, the method includes embedding a sinter-bonded heat dissipation structure in a module substrate. The step of embedding may entail applying a sinter precursor material containing metal particles into a cavity provided in the module substrate, and subsequently sintering the sinter precursor material at a maximum processing temperature less than a melt point of the metal particles to produce a sintered metal body bonded to the module substrate. A microelectronic device and a heatsink are then attached to the module substrate before, after, or concurrent with sintering such that the heatsink is thermally coupled to the microelectronic device through the sinter-bonded heat dissipation structure. In certain embodiments, the microelectronic device may be bonded to the module substrate at a location overlying the thermally-conductive structure.
    Type: Grant
    Filed: September 19, 2018
    Date of Patent: September 22, 2020
    Assignee: NXP USA, Inc.
    Inventors: Lakshminarayan Viswanathan, Elie A. Maalouf, Geoffrey Tucker
  • Patent number: 10741446
    Abstract: A method of wafer dicing includes singulating dies from a semiconductor wafer. The method further includes depositing a metal layer on back sides of the singulated dies, wherein a portion of the metal layer continues beyond the backs sides of the singulated dies to deposit at least partially on lateral sides of the singulated dies. A packaged die includes a semiconductor die and a metal outer layer deposited on the back side of the semiconductor die and on a portion of the lateral side of the semiconductor die nearest the back side. The packaged die further includes a substrate mounted to the back side of the semiconductor die a die attach material that bonds the substrate to the metal outer layer deposited on the semiconductor die, wherein the metal outer layer and the die attach material surround the back edge of the semiconductor die.
    Type: Grant
    Filed: July 5, 2017
    Date of Patent: August 11, 2020
    Assignee: NXP USA, Inc.
    Inventors: Jaynal A Molla, Lakshminarayan Viswanathan, David Abdo, Colby Greg Rampley, Fernando A. Santos
  • Patent number: 10727153
    Abstract: A semiconductor device and a method of manufacturing the same include a die and a planar thermal layer, and a thick-silver layer having a thickness of at least four (4) micrometers disposed directly onto a first planar side of the planar thermal layer, as well as a metallurgical die-attach disposed between the thick-silver layer and the die, the metallurgical die-attach directly contacting the thick-silver layer.
    Type: Grant
    Filed: May 30, 2017
    Date of Patent: July 28, 2020
    Assignee: NXP USA, Inc.
    Inventors: Lakshminarayan Viswanathan, Jaynal A Molla
  • Publication number: 20200211932
    Abstract: Internally-shielded microelectronic packages having increased resistances to electromagnetic cross-coupling are disclosed, as are methods for fabricating such microelectronic packages. In embodiments, the internally-shielded microelectronic package includes a substrate having a frontside and a longitudinal axis. A first microelectronic device is mounted to the frontside of the substrate, while a second microelectronic device is further mounted to the frontside of the substrate and spaced from the first microelectronic device along the longitudinal axis. An internal shield structure includes or consists of a shield wall, which is positioned between the first and second microelectronic devices as taken along the longitudinal axis. The internal shield structure is at least partially composed of a magnetically-permeable material, which decreases electromagnetic cross-coupling between the first and second microelectronic devices during operation of the internally-shielded microelectronic package.
    Type: Application
    Filed: March 12, 2020
    Publication date: July 2, 2020
    Applicant: NXP USA, INC.
    Inventors: AUDEL SANCHEZ, LAKSHMINARAYAN VISWANATHAN, VIKAS SHILIMKAR, RAMANUJAM SRINIDHI EMBAR
  • Patent number: 10629518
    Abstract: Internally-shielded microelectronic packages having increased resistances to electromagnetic cross-coupling are disclosed, as are methods for fabricating such microelectronic packages. In embodiments, the internally-shielded microelectronic package includes a substrate having a frontside and a longitudinal axis. A first microelectronic device is mounted to the frontside of the substrate, while a second microelectronic device is further mounted to the frontside of the substrate and spaced from the first microelectronic device along the longitudinal axis. An internal shield structure includes or consists of a shield wall, which is positioned between the first and second microelectronic devices as taken along the longitudinal axis. The internal shield structure is at least partially composed of a magnetically-permeable material, which decreases electromagnetic cross-coupling between the first and second microelectronic devices during operation of the internally-shielded microelectronic package.
    Type: Grant
    Filed: August 29, 2018
    Date of Patent: April 21, 2020
    Assignee: NXP USA, Inc.
    Inventors: Audel Sanchez, Lakshminarayan Viswanathan, Vikas Shilimkar, Ramanujam Srinidhi Embar
  • Publication number: 20200075463
    Abstract: Internally-shielded microelectronic packages having increased resistances to electromagnetic cross-coupling are disclosed, as are methods for fabricating such microelectronic packages. In embodiments, the internally-shielded microelectronic package includes a substrate having a frontside and a longitudinal axis. A first microelectronic device is mounted to the frontside of the substrate, while a second microelectronic device is further mounted to the frontside of the substrate and spaced from the first microelectronic device along the longitudinal axis. An internal shield structure includes or consists of a shield wall, which is positioned between the first and second microelectronic devices as taken along the longitudinal axis. The internal shield structure is at least partially composed of a magnetically-permeable material, which decreases electromagnetic cross-coupling between the first and second microelectronic devices during operation of the internally-shielded microelectronic package.
    Type: Application
    Filed: August 29, 2018
    Publication date: March 5, 2020
    Applicant: NXP USA, INC.
    Inventors: AUDEL SANCHEZ, LAKSHMINARAYAN VISWANATHAN, VIKAS SHILIMKAR, RAMANUJAM SRINIDHI EMBAR
  • Patent number: 10573594
    Abstract: A single semiconductor device package that reduces electromagnetic coupling between elements of a semiconductor device embodied within the package is provided. For a dual-path amplifier, such as a Doherty power amplifier, an isolation feature that separates carrier amplifier elements from peaking amplifier elements is included within the semiconductor device package. The isolation feature can take the form of a structure that is constructed of a conductive material coupled to ground and which separates the elements of the amplifier. The isolation feature can be included in a variety of semiconductor packages, including air cavity packages and overmolded packages. Through the use of the isolation feature provided by embodiments of the present invention a significant improvement in signal isolation between amplifier elements is realized, thereby improving performance of the dual-path amplifier.
    Type: Grant
    Filed: April 12, 2016
    Date of Patent: February 25, 2020
    Assignee: NXP USA, Inc.
    Inventors: Peter H. Aaen, David J. Dougherty, Manuel F. Romero, Lakshminarayan Viswanathan