Patents by Inventor Anindya Poddar

Anindya Poddar 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: 7612435
    Abstract: A method of packaging an integrated circuit die having a plurality of I/O pads is described. The method includes positioning the die within a die attach area of a first leadframe that includes a plurality of first leads. The method also includes positioning a second leadframe that includes a plurality of second leads over the first leadframe. The method further includes electrically connecting each of the second leads to both an associated I/O pad and a first lead.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: November 3, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Jaime A. Bayan, Anindya Poddar
  • Publication number: 20090267216
    Abstract: Apparatuses and methods for inkjet printing electrical interconnect patterns such as leadframes for integrated circuit devices are disclosed. An apparatus for packaging includes a thin substrate adapted for high temperature processing, and an attach pad and contact regions that are inkjet printed to the thin substrate using a metallic nanoink. The nanoink is then cured to remove liquid content. The residual metallic leadframe or electrical interconnect pattern has a substantially consistent thickness of about 10 to 50 microns or less. An associated panel assembly includes a conductive substrate panel having multiple separate device arrays comprising numerous electrical interconnect patterns each, a plurality of integrated circuit devices mounted on the conductive substrate panel, and a molded cap that encapsulates the integrated circuit devices and associated electrical interconnect patterns.
    Type: Application
    Filed: April 28, 2008
    Publication date: October 29, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Randall L. Walberg, Luu T. Nguyen, Anindya Poddar
  • Publication number: 20090174069
    Abstract: A semiconductor device is described. The device includes an integrated circuit die having an active surface that includes a plurality of input/output (I/O) pads. The device further includes a plurality of crack resistant structures. Each crack resistant structure is formed over an associated I/O pad and includes an associated raised portion. Each I/O pad may be bumped with solder such that a solder bump is formed over the associated crack resistant structure on the I/O pad.
    Type: Application
    Filed: January 4, 2008
    Publication date: July 9, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Hau Nguyen, Luu T. Nguyen, Anindya Poddar
  • Publication number: 20090160037
    Abstract: A method of packaging an integrated circuit die having a plurality of I/O pads is described. The method includes positioning the die within a die attach area of a first leadframe that includes a plurality of first leads. The method also includes positioning a second leadframe that includes a plurality of second leads over the first leadframe. The method further includes electrically connecting each of the second leads to both an associated I/O pad and a first lead.
    Type: Application
    Filed: December 21, 2007
    Publication date: June 25, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Jaime A. BAYAN, Anindya PODDAR
  • Publication number: 20090115035
    Abstract: Integrated circuit (IC) packages are described. Each IC package includes a die having an exposed metallic layer deposited on its back surface. Solder joints are arranged to physically and electrically connect I/O pads on the active surface of the die with associated leads. A molding material encapsulates portions of the die, leadframe and solder joint connections while leaving the metallic layer exposed and uncovered by molding material.
    Type: Application
    Filed: November 6, 2007
    Publication date: May 7, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Jaime A. BAYAN, Anindya Poddar
  • Publication number: 20090072367
    Abstract: Particular embodiments of the present invention provide a leadframe suitable for use in packaging IC dice that enables stress reduction in and around the die, die attach material, die attach pad and mold interfaces. More particularly, various leadframes are described that include recesses in selected regions of the top surface of the die attach pad.
    Type: Application
    Filed: July 2, 2008
    Publication date: March 19, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Anindya PODDAR, Lianxi SHEN
  • Patent number: 7491625
    Abstract: A method of handling an IC wafer that includes a multiplicity of dice is described. Solder bumps are formed on bond pads on the active surface of the wafer. The back surface of the bumped wafer is adhered to a first mount tape. The wafer is singulated while it is still secured to the first tape to provide a multiplicity of individual dice. The active surfaces of the singulated dice are then adhered to a second tape with the first tape still adhered to the back surfaces of the dice. The first tape may then be removed. In this manner, the back surfaces of the dice may be left exposed and facing upwards with the active surfaces of the dice adhered to the second tape. The described method permits the use of a conventional die attach machine that is not designated for use as a flip-chip die attach machine.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: February 17, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Jaime A. Bayan, Nghia Tu, Anindya Poddar, Ashok Prabhu
  • Publication number: 20090026621
    Abstract: A combination of layout improvements and inner layer dielectric (ILD) material improvements provides a bond pad stack that is robust for both gold (Au) and copper (Cu) wires in circuits with only one or two pad metal layers. The layout improvements involve removing all vias between the top metal layer and the metal layers below top metal in the area under the passivation opening (where probe tips and the bond wire are placed). This allows for a more homogenous material without via discontinuities, thereby reducing stress concentration points in the ILD. The ILD material improvement involves adding a layer of silicon nitride in addition to the silicon oxide layer. Traditionally, the ILD consists of either spun-on or high density plasma (HDP) oxides. The growth of the thin layer of silicon nitride over the oxide on the topmost ILD layer provides a composite of significantly increased toughness and prevents cracks or other damage from propagating into the underlying active circuits and routing.
    Type: Application
    Filed: August 27, 2007
    Publication date: January 29, 2009
    Inventor: Anindya Poddar
  • Publication number: 20080241993
    Abstract: A method of handling an IC wafer that includes a multiplicity of dice is described. Solder bumps are formed on bond pads on the active surface of the wafer. The back surface of the bumped wafer is adhered to a first mount tape. The wafer is singulated while it is still secured to the first tape to provide a multiplicity of individual dice. The active surfaces of the singulated dice are then adhered to a second tape with the first tape still adhered to the back surfaces of the dice. The first tape may then be removed. In this manner, the back surfaces of the dice may be left exposed and facing upwards with the active surfaces of the dice adhered to the second tape. The described method permits the use of a conventional die attach machine that is not designated for use as a flip-chip die attach machine.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 2, 2008
    Inventors: Jaime A. Bayan, Nghia Tu, Anindya Poddar, Ashok Prabhu
  • Publication number: 20080241991
    Abstract: An improved method and apparatus for packaging integrated circuits are described. More particularly, a method and apparatus for use in securing a plurality of integrated circuit dice to a lead frame panel are described. Each integrated circuit die includes an active surface having a multiplicity of solder bumps. The lead frame panel includes an array of device areas, each including a plurality of leads. The method includes positioning a plurality of dice into designated positions on a carrier such that the active surfaces of the dice are facing upwards. The carrier includes a carrier frame including an associated array of carrier device areas. A lead frame panel may be positioned over the carrier such that the solder bumps on the active surfaces of the dice are adjacent and in contact with the associated leads of the associated device areas.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 2, 2008
    Inventors: Anindya Poddar, Jaime A. Bayan, Ashok S. Prabhu, Will K. Wong
  • Patent number: 7385297
    Abstract: An under bond pad structure is described for integrated circuit dice are that have active circuits located below at least some of the bond pads. The metallization layers interconnection structures within the die are arranged so that electrically conductive vias do not extend between the bond pads and any underlying metallization layer in a region that overlies an active circuit. In some embodiments, no conductive vias are provided between any of the metallization layers in regions that underlie the bond pads and overlie an active circuit. The described arrangements significantly improve the resistance to cracking in the dielectric layers beneath the bond pad (and particularly the topmost intermediate dielectric layer) when wire bonding is used to electrically connect such dice within a package.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: June 10, 2008
    Assignee: National Semiconductor Corporation
    Inventors: Vijaylaxmi Gumaste, Anindya Poddar
  • Patent number: 7354802
    Abstract: In one aspect, an improved wafer mount tape is provided. The wafer mount tape includes a base layer, a release layer that expands when activated and a B-stageable adhesive layer that is positioned over the release layer. In a method aspect of the invention, a wafer level method of placing an adhesive layer on the back surface of integrated circuit devices is described. In this aspect, a wafer is secured to the mount tape. The wafer is diced while the wafer is attached to the mounting tape. After the wafer has been diced and any other desired wafer level processing is completed, the dice may be released individually or in groups by heating (or otherwise activating) localized areas of the tape under selected die to a temperature sufficient to release the selected die. The expansion of the release layer during the release operation serves to lift the selected die relative to adjacent die thereby facilitating picking.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: April 8, 2008
    Assignee: National Semiconductor Corporation
    Inventors: Anindya Poddar, Chetan Paydenkar
  • Patent number: 7101620
    Abstract: In one aspect, an improved wafer mount tape is provided. The wafer mount tape includes a base layer, a release layer that expands when activated and a B-stageable adhesive layer that is positioned over the release layer. In a method aspect of the invention, a wafer level method of placing an adhesive layer on the back surface of integrated circuit devices is described. In this aspect, a wafer is secured to the mount tape. The wafer is diced while the wafer is attached to the mounting tape. After the wafer has been diced and any other desired wafer level processing is completed, the dice may be released individually or in groups by heating (or otherwise activating) localized areas of the tape under selected die to a temperature sufficient to release the selected die. The expansion of the release layer during the release operation serves to lift the selected die relative to adjacent die thereby facilitating picking.
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: September 5, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Anindya Poddar, Chetan Paydenkar
  • Patent number: 7015587
    Abstract: A stacked multi-chip package is described in which a base die is electrically connected to both an interconnect structure (e.g., a lead frame or a substrate) and a stacked die. A first encapsulant is used to cover some, but not all of the bond pads on a base die as well as portions of their associated electrical connectors (e.g. bonding wires). A surface of the first encapsulant is arranged to support the stacked die. The stacked die is directly electrically connected to bond pads that are not covered by the first encapsulant. A second encapsulant at least partially encapsulates the base and stacked dice and the various electrical connectors. With this arrangement, a stacked multi-chip semiconductor package is provided that includes a direct die-to-die electrical connection.
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: March 21, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Anindya Poddar
  • Patent number: 6933597
    Abstract: A method for providing passive circuit functions in a multi-chip module and the multi-chip modules that result from incorporating these function is disclosed. Passive components such as resistors, capacitors and inductors are fabricated on or within a non-conductive spacer. The spacer is then placed between two active semiconductor dies and coupled electrically to either one or both of the dies. In this manner, area of the active dies that would normally have to be used for such passive components is freed for other uses and the spacer, which was already required in multi-chip modules, is endowed with extra functionality. In another embodiment, one or both surfaces of the spacer are coated with a conductive metal and the passive components are located within the spacer. In this embodiment, the spacer provides electromagnetic interference protection between the active dies.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: August 23, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Anindya Poddar, Ashok S. Prabhu
  • Patent number: 6664615
    Abstract: Integrated circuit (IC) package structures and IC package fabrication techniques are provided. The IC package substrate is formed from a metal sheet that is patterned to form a substrate with pads and leads. These pads and leads are pattered throughout the substrate including at least part of the die mounting area. The die is mounted onto the die mounting area of the lead-frame, and respective bonding terminals on the die are electrically connected to the associated bonding areas on the patterned leads. A protective encapsulant is molded to cover the die, bond wires, and most, if not all, of the patterned substrate. Contacts for external electrical connection are formed onto the bottom of the pads.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: December 16, 2003
    Assignee: National Semiconductor Corporation
    Inventors: Jaime Bayan, Anindya Poddar
  • Patent number: 6607941
    Abstract: A variety of improved shell case style packages as well as shell case style wafer level packaging processes are described. Generally, in shell case style packaging, traces are patterned on the top surface of a wafer. In some embodiments, the conductors formed along the sides of the package are formed from at least a couple conductor layers to improve the adhesion of the conductors to the traces formed on the top surface of the devices. In some embodiments the conductors are patterned during processing such that the conductors are not cut during the wafer dicing operation. This arrangement is particularly useful when the conductors are formed at least partially from aluminum (or other metals that oxidize in ambient air). In other embodiments, BCB is not used under the trace layer in regions that will have notches formed therein so that the resulting package does not have any exposed BCB/trace junctions. In some embodiments, no BCB layer whatsoever is applied during packaging.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: August 19, 2003
    Assignee: National Semiconductor Corporation
    Inventors: Ashok Prabhu, Nikhil Kelkar, Anindya Poddar
  • Patent number: 6603199
    Abstract: A single tier cavity down integrated circuit package having a die with outer bond pads and staggered inner bond pads is described. The bond pads of the die are assigned to associated supply rings and bond fingers of the package according to a design methodology where in one embodiment at least all bond pads connected to the supply rings are outer bond pads, and staggered inner bond pads are connected to bond fingers. There is further described a method for assigning bond pads of the die to associated supply rings and bond fingers of the package, as well as, a die having staggered bond pads formed in accordance with the method of the present invention.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: August 5, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Anindya Poddar
  • Publication number: 20030134453
    Abstract: A variety of improved shell case style packages as well as shell case style wafer level packaging processes are described. Generally, in shell case style packaging, traces are patterned on the top surface of a wafer. In some embodiments, the conductors formed along the sides of the package are formed from at least a couple conductor layers to improve the adhesion of the conductors to the traces formed on the top surface of the devices. In some embodiments the conductors are patterned during processing such that the conductors are not cut during the wafer dicing operation. This arrangement is particularly useful when the conductors are formed at least partially from aluminum (or other metals that oxidize in ambient air). In other embodiments, BCB is not used under the trace layer in regions that will have notches formed therein so that the resulting package does not have any exposed BCB/trace junctions. In some embodiments, no BCB layer whatsoever is applied during packaging.
    Type: Application
    Filed: January 11, 2002
    Publication date: July 17, 2003
    Applicant: National Semiconductor Corporation
    Inventors: Ashok Prabhu, Nikhil Kelkar, Anindya Poddar
  • Patent number: 6509635
    Abstract: Grid array-type packages having a die offset relative to the center point of the surface of the package substrate are described. In some embodiments, the die may be attached in a die attach area offset on the surface of the substrate relative to the center point of the surface of the substrate. In other embodiments, the die may be mounted in a die cavity formed in the substrate and offset relative to the center point of the surface of the substrate. In packaging die having an unequal distribution of bond pads, in one embodiment, the die, die attach area and/or die cavity are offset on the substrate away from the side of the die having the higher bond pad density and toward the side of the die having the lower bond pad density so as to increase available routing space on the side of the substrate adjacent the side of the die having the higher bond pad density.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: January 21, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Anindya Poddar