Patents by Inventor Siuli Sarkar

Siuli Sarkar 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: 20180290244
    Abstract: A lead-free solder alloy, comprising from 35 to 59% wt Bi; Cu in a concentration up to 1.0 wt %; from 0.01 to 0.5 wt % Ni; and the balance Sn, together with any unavoidable impurities, with certain embodiments further comprising Ag, such as up to 1 wt % Ag.
    Type: Application
    Filed: June 8, 2018
    Publication date: October 11, 2018
    Inventors: Ranjit Pandher, Bawa Singh, Siuli Sarkar, Sujatha Chegudi, Anil K.N. Kumar, Kamanio Chattopadhyay, Dominic Lodge, Morgana de Avila Ribas
  • Publication number: 20180102464
    Abstract: Improved electrical and thermal properties of solder alloys are achieved by the use of micro-additives in solder alloys to engineer the electrical and thermal properties of the solder alloys and the properties of the reaction layers between the solder and the metal surfaces. The electrical and thermal conductivity of alloys and that of the reaction layers between the solder and the -metal surfaces can be controlled over a wide range of temperatures. The solder alloys produce stable microstructures wherein such stable microstructures of these alloys do not exhibit significant changes when exposed to changes in temperature, compared to traditional interconnect materials.
    Type: Application
    Filed: October 6, 2016
    Publication date: April 12, 2018
    Inventors: Morgana de Avila Ribas, Pritha Choudhury, Siuli Sarkar, Ranjit Pandher, Nicholas G. Herrick, Amit Patel, Ravindra M Bhatkal, Bawa Singh
  • Publication number: 20180072573
    Abstract: A method of synthesizing high quality graphene for producing graphene particles and flakes is presented. The engineered qualities of the graphene include size, aspect ratio, edge definition, surface functionalization and controlling the number of layers. Fewer defects are found in the end graphene product in comparison to previous methods. The inventive method of producing graphene is less aggressive, lower cost and more environmentally friendly than previous methods. This method is applicable to both laboratory scale and high volume manufacturing for producing high quality graphene flakes.
    Type: Application
    Filed: September 14, 2016
    Publication date: March 15, 2018
    Inventors: Nirmalya Kumar Chaki, Barun Das, Supriya Devarajan, Siuli Sarkar, Rahul Raut, Bawa Singh, Ranjit Pandher, Oscar Khaselev
  • Publication number: 20180056455
    Abstract: A composition for use in an electronic assembly process, the composition comprising a filler dispersed in an organic medium, wherein: the organic medium comprises a polymer; the filler comprises one or more of graphene, functionalized graphene, graphene oxide, a polyhedral oligomeric silsesquioxane, graphite, a 2D material, aluminum oxide, zinc oxide, aluminum nitride, boron nitride, silver, nano fibers, carbon fibers, diamond, carbon nanotubes, silicon dioxide and metal-coated particles, and the composition comprises from 0.001 to 40 wt. % of the filler based on the total weight of the composition.
    Type: Application
    Filed: March 31, 2016
    Publication date: March 1, 2018
    Inventors: Ramakrishna Hosur Venkatagiriyappa, Morgana De Avila Ribas, Barun Das, Harish Hanchina Siddappa, Sutapa Mukherjee, Siuli Sarkar, Bawa Singh, Rahul Raut, Ranjit Pandher
  • Patent number: 9802275
    Abstract: Rosin-free thermosetting flux formulations for enhancing the mechanical reliability of solder joints. In accordance with one or more aspects, a solder paste as shown and described herein imparts improved or enhanced solder joint properties relating to at least one of drop shock, thermal cycling, thermal shock, shear strength, flexural strength performance, and/or other thermal-mechanical performance attributes.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: October 31, 2017
    Inventors: Morgana de Avila Ribas, Rahul Raut, Traian Cornel Cucu, Shu Tai Yong, Siuli Sarkar, Ramakrishna Hosur Katagiriyappa
  • Publication number: 20170304955
    Abstract: The invention provides an alloy, preferably a lead-free solder alloy, comprising: from 35 to 59% wt Bi; from 0 to .0 wt % Ag; from 0 to 1.0% wt Au; from 0 to 1.0% wt Cr; from 0 to 2.0% wt In; from 0 to 1.0% wt P; from 0 to 1.0% wt Sb; from 0 to 1.0% wt Sc; from 0 to 1.0% wt Y; from 0 to 1.0% wt Zn; from 0 to 1.0% wt rare earth elements; one or more of: 10 from greater than 0 to 1.0% wt Al; from 0.01 to 1.0% wt Ce; from greater than 0 to 1.0% wt Co; from greater than 0 to .0% wt Cu; from 0.001 to 1.0% wt Ge; from greater than 0 to .0% wt Mg; from greater than 0 to 1.0% wt Mn; from 0.01 to 1.0% wt Ni; and from greater than 0 to 1.0% wt Ti, and the 1 balance Sn, together with any unavoidable impurities.
    Type: Application
    Filed: July 7, 2017
    Publication date: October 26, 2017
    Inventors: Ranjit Pandher, Bawa Singh, Siuli Sarkar, Sujatha Chegudi, Anil K. N. Kumar, Kamanio Chattopadhyay, Dominic Lodge, Morgana de Avila Ribas
  • Patent number: 9786629
    Abstract: Dual-side reinforcement (DSR) materials and methods for semiconductor fabrication. The DSR materials exhibit the properties of conventional underfill materials with enhanced stability at room temperature.
    Type: Grant
    Filed: July 31, 2014
    Date of Patent: October 10, 2017
    Inventors: Ramakrishna Hosur Venkatagiriyappa, Sutapa Mukherjee, Harish Hanchina Siddappa, Morgana De Avila Ribas, Siuli Sarkar, Bawa Singh, Rahul Raut
  • Patent number: 9751159
    Abstract: Flux formulations that remain pliable and tack-free after deposition are disclosed. In certain examples, the flux comprises a first component and an effective amount of a second component to provide a pliable flux after deposition. The flux may also include activators, plasticizers, surface active agents and other components.
    Type: Grant
    Filed: December 27, 2016
    Date of Patent: September 5, 2017
    Inventors: Narahari Pujari, Sanyogita Arora, Siuli Sarkar, Anna Lifton, Rahul Raut, Bawa Singh
  • Publication number: 20170200527
    Abstract: A conductive paste and method of manufacturing thereof. The conductive paste comprises conductive particles dispersed in an organic medium, the organic medium comprising: (a) a solvent; and (b) a binder comprising a polyester. The conductive paste typically comprises silver and may contain various other additives. A stretchable conductive layer can be formed by curing the conductive paste.
    Type: Application
    Filed: July 14, 2015
    Publication date: July 13, 2017
    Inventors: Narahari PUJARI, Bawa SINGH, Ravi BHATKAL, Siuli SARKAR, Anubhav RUSTOGI
  • Publication number: 20170197281
    Abstract: A lead-free, antimony-free solder alloy_suitable for use in electronic soldering applications. The solder alloy comprises (a) from 1 to 4 wt. % silver; (b) from 0.5 to 6 wt. % bismuth; (c) from 3.55 to 15 wt. % indium, (d) 3 wt. % or less of copper; (e) one or more optional elements and the balance tin, together with any unavoidable impurities.
    Type: Application
    Filed: July 15, 2015
    Publication date: July 13, 2017
    Inventors: Pritha Choudhury, Morgana De Avila Ribas, Sutapa Mukherjee, Siuli Sarkar, Ranjit Pandher, Ravindra Bhatkal, Bawa Singh
  • Publication number: 20170144221
    Abstract: Methods for die attachment of multichip and single components including flip chips may involve printing a sintering paste on a substrate or on the back side of a die. Printing may involve stencil printing, screen printing, or a dispensing process. Paste may be printed on the back side of an entire wafer prior to dicing, or on the back side of an individual die. Sintering films may also be fabricated and transferred to a wafer, die or substrate. A post-sintering step may increase throughput.
    Type: Application
    Filed: June 12, 2015
    Publication date: May 25, 2017
    Inventors: Shamik GHOSHAL, V. Sathish KUMAR, Pavan VISHWANATH, Ranjit S. PANDHER, Remya CHANDRAN, Sutapa MUKHERJEE, Siuli SARKAR, Bawa SINGH, Ravindra Mohan BHATKAL
  • Publication number: 20170136583
    Abstract: A lead-free solder alloy comprising 35-59 wt % Bi, Mn in a concentration up to 1.0 wt %, Cu in a concentration of up to 1 wt %, and balance Sn, together with any unavoidable impurities. Some embodiments also contain up to about 1 wt % Ag.
    Type: Application
    Filed: January 30, 2017
    Publication date: May 18, 2017
    Inventors: Ranjit Pandher, Bawa Singh, Siuli Sarkar, Sujatha Chegudi, Anil K. N. Kumar, Kamanio Chattopadhyay, Dominic Lodge, Morgana de Avila Ribas
  • Publication number: 20170135227
    Abstract: A method of forming a solder joint, the method comprising: (i) providing a solder flux; (ii) providing solder particles; (iii) providing two or more work pieces to be joined; and (iv) heating the solder flux and the solder particles in the vicinity of the two or more work pieces to be joined to form: (i) a solder joint between the two or more work pieces to be joined, and (ii) a solder flux residue. The solder flux residue substantially covers the exposed surfaces of the solder joint.
    Type: Application
    Filed: June 19, 2015
    Publication date: May 11, 2017
    Inventors: Hosur Venkatagiriyappa Ramakrishna, Morgana De Avila Ribas, Ranjit Pandher, Siuli Sarkar, Sutapa Mukherjee, Bawa Singh
  • Publication number: 20170113306
    Abstract: A sintering powder, wherein a least a portion of the particles making up the sintering powder comprise: a core comprising a first material; and a shell at least partially coating the core, the shell comprising a second material having a lower oxidation potential than the first material.
    Type: Application
    Filed: June 22, 2015
    Publication date: April 27, 2017
    Inventors: Shamik Ghoshal, Remya Chandran, Sutapa Mukherjee, Siuli Sarkar, Ranjit Pandher, Bawa Singh
  • Publication number: 20170106479
    Abstract: Flux formulations that remain pliable and tack-free after deposition are disclosed. In certain examples, the flux comprises a first component and an effective amount of a second component to provide a pliable flux after deposition. The flux may also include activators, plasticizers, surface active agents and other components.
    Type: Application
    Filed: December 27, 2016
    Publication date: April 20, 2017
    Inventors: Narahari Pujari, Sanyogita Arora, Siuli Sarkar, Anna Lifton, Rahul Raut, Bawa Singh
  • Patent number: 9566668
    Abstract: Flux formulations that remain pliable and tack-free after deposition are disclosed. In certain examples, the flux comprises a first component and an effective amount of a second component to provide a pliable flux after deposition. The flux may also include activators, plasticizers, surface active agents and other components.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: February 14, 2017
    Inventors: Narahari Pujari, Sanyogita Arora, Siuli Sarkar, Anna Lifton, Rahul Raut, Bawa Singh
  • Publication number: 20170028477
    Abstract: A method for manufacturing metal powder comprising: providing a basic metal salt solution; contacting the basic metal salt solution with a reducing agent to precipitate metal powder therefrom; and recovering precipitated metal powder from the solvent.
    Type: Application
    Filed: April 10, 2015
    Publication date: February 2, 2017
    Inventors: Rohan P. Setna, Nirmalya Kumar Chaki, Poulami Sengupta Roy, Siuli Sarkar, Sutapa Mukherjee
  • Publication number: 20170033073
    Abstract: A sintering powder comprising: a first type of metal particles having a mean longest dimension of from 100 nm to 50 ?m.
    Type: Application
    Filed: April 10, 2015
    Publication date: February 2, 2017
    Inventors: Shamik GHOSHAL, Nirmalya Kumar CHAKI, Poulami Sengupta ROY, Siuli SARKAR, Anubhav RUSTOGI
  • Publication number: 20160318134
    Abstract: Rosin-free thermosetting flux formulations for enhancing the mechanical reliability of solder joints. In accordance with one or more aspects, a solder paste as shown and described herein imparts improved or enhanced solder joint properties relating to at least one of drop shock, thermal cycling, thermal shock, shear strength, flexural strength performance, and/or other thermal-mechanical performance attributes.
    Type: Application
    Filed: December 31, 2014
    Publication date: November 3, 2016
    Applicant: Alpha Metals, Inc.
    Inventors: Morgana de Avila Ribas, Rahul Raut, Traian Cornel CUCU, Shu Tai Yong, Siuli Sarkar, Ramakrishna Hosur Katagiriyappa
  • Publication number: 20160304989
    Abstract: A method for recovering tin and/or tin alloy from a substrate comprising providing a substrate having tin and/or tin alloy thereon; contacting the tin and/or tin alloy with a stripping solution comprising an inorganic acid and a persulfate compound; recovering tin salt and/or tin alloy salt precipitated from the stripping solution; and recovering tin and/or tin alloy from the tin salt and/or tin alloy salt, respectively.
    Type: Application
    Filed: July 2, 2014
    Publication date: October 20, 2016
    Applicant: Alpha Metals, Inc.
    Inventors: Narahari Pujari, Siuli Sarkar, Bawa Singh, Daniel Goswami