Patents Assigned to Asat Ltd.
  • Publication number: 20060223229
    Abstract: A ball grid array integrated circuit package is manufactured by mounting a semiconductor die, to a first surface of a substrate such that bumps on the semiconductor die are electrically connected to conductive traces of the substrate. At least one collapsible spacer is mounted to at least one of a heat spreader, the semiconductor die and the substrate. The heat spreader is fixed to the at least one of the first surface of the substrate and the semiconductor die such that the at least one collapsible spacer is disposed therebetween. A ball grid array is formed on a second surface of the substrate, bumps of the ball grid array being electrically connected to the conductive traces and the integrated circuit package is singulated.
    Type: Application
    Filed: March 17, 2006
    Publication date: October 5, 2006
    Applicant: ASAT Ltd.
    Inventors: Mohan Kirloskar, Chun Fan, Neil McLellan
  • Patent number: 7081403
    Abstract: A leadless plastic chip carrier is fabricated by selectively etching a leadframe strip to reduce a thickness of the strip at a portion thereof. Selectively masking the surface of the leadframe strip using a mask, follows selectively etching, to provide exposed areas of the surface at the portion and contact pad areas on leadframe the strip. At least one layer of metal is deposited on the exposed areas to define a die attach pad on the portion of the leadframe strip with reduced thickness and to define contact pads on the surface of the strip. At least one semiconductor die is mounted to the die attach pad, followed by wire bonding the at least one semiconductor die to ones of the contact pads. The at least one semiconductor die, the wire bonds, and the contact pads are covered with an overmold material and the leadframe strip is etched to thereby remove the leadframe strip. The leadless plastic chip carrier is singulated from the leadframe strip.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: July 25, 2006
    Assignee: ASAT Ltd.
    Inventors: Mohan Kirloskar, Chun Ho Fan, Kwok Cheung Tsang, Kin Pui Kwan
  • Patent number: 7071545
    Abstract: An integrated circuit package is provided. The package includes a die attach pad having a first side and a second side. A first semiconductor die is mounted to the first side of the die attach pad, a plurality of contact pads disposed in close proximity to the first semiconductor die. A first plurality of wire bonds connect the first semiconductor die and ones of the contact pads. An overmold encapsulates the first plurality of wire bonds and the first semiconductor die, the die attach pad and the contact pads being embedded in the overmold. A plurality of leads are disposed proximal the second side of the die attach pad. A second semiconductor die is mounted to one of the second side of the die attach pad and ones of the plurality of leads such that the ones of the plurality of leads are electrically connected to the second semiconductor die. The second semiconductor die and the leads are embedded in an encapsulant. The die attach pad shields the second semiconductor die.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: July 4, 2006
    Assignee: ASAT Ltd.
    Inventors: Viresh Patel, Mohan Kirloskar
  • Patent number: 7049177
    Abstract: A process for fabricating a leadless plastic chip carrier includes selectively etching at least a first surface of a leadframe strip to partially define at least a plurality of contact pads and a die attach pad; selectively plating at least one layer of metal on a second surface of the leadframe strip, on an undersurface of at least the plurality of contact pads and the die attach pad; mounting a semiconductor die on the first surface, on the partially defined die attach pad; wire bonding the semiconductor die to ones of the contact pads; encapsulating the wire bonds and the semiconductor die in a molding material such that the molding material covers a first portion of the die attach pad and first portions of the contact pads; selectively etching a second surface of the leadframe strip to define a second portion of the contact pads and a second portion of the die attach pad by etching the second surface with the at least one layer of metal resisting etching; and singulating the leadless plastic chip carrier
    Type: Grant
    Filed: January 28, 2004
    Date of Patent: May 23, 2006
    Assignee: ASAT Ltd.
    Inventors: Chun Ho Fan, Wing Him Lau, Kenneth Kwan, Janet Wong
  • Patent number: 7033517
    Abstract: A leadless plastic chip carrier is fabricated by partially etching at least a first surface of a leadframe strip to partially define a die attach pad, a plurality of contact pads disposed around the die attach pad, and a plurality of bond fingers intermediate the die attach pad and the contact pads. A metal strip is laminated to the first surface of the leadframe strip. A second surface of the leadframe strip is selectively etched such that portions of the leadframe strip are removed to define a remainder of the die attach pad, the plurality of contact pads, the plurality of bond fingers and circuitry between ones of the bond fingers and ones the contact pads. A semiconductor die is mounted to the die attach pad and wire bonds connect the semiconductor die to ones of the bond fingers. The second surface of the leadframe strip, the semiconductor die and the wire bonds are encapsulated in a molding material.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: April 25, 2006
    Assignee: ASAT Ltd.
    Inventors: Chun Ho Fan, Mohan Kirloskar
  • Patent number: 7009286
    Abstract: A leadless plastic chip carrier is fabricated by selectively etching a leadframe strip to reduce a thickness of the strip at a portion thereof. Selectively masking the surface of the leadframe strip using a mask, follows selectively etching, to provide exposed areas of the surface at the portion and contact pad areas on leadframe the strip. At least one layer of metal is deposited on the exposed areas to define a die attach pad on the portion of the leadframe strip with reduced thickness and to define contact pads on the surface of the strip. At least one semiconductor die is mounted to the die attach pad, followed by wire bonding the at least one semiconductor die to ones of the contact pads. The at least one semiconductor die, the wire bonds, and the contact pads are covered with an overmold material and the leadframe strip is etched to thereby remove the leadframe strip. The leadless plastic chip carrier is singulated from the leadframe strip.
    Type: Grant
    Filed: January 15, 2004
    Date of Patent: March 7, 2006
    Assignee: ASAT Ltd.
    Inventors: Mohan Kirloskar, Chun Ho Fan, Kwok Cheung Tsang, Kin Pui Kwan
  • Patent number: 6995460
    Abstract: A leadless plastic chip carrier is constructed by half etching one or both sides of the package design onto a leadframe strip so as to create unique design features such as power and/or ground ring surrounding the die attach pad, interlocking rivet head construction for the contact pads, and an interlocking pattern for the die attach pad. After wire bonding and molding, a further etching is performed to isolate and expose contact pads. Singulation of individual chip packages from the leadframe strip is then performed by saw singulation or die punching.
    Type: Grant
    Filed: May 6, 2005
    Date of Patent: February 7, 2006
    Assignee: ASAT Ltd.
    Inventors: Neil McLellan, Chun Ho Fan, Kwok Cheung Tsang, Kin Pui Kwan, Wing Him Lau
  • Patent number: 6989294
    Abstract: A leadless plastic chip carrier is constructed by half etching one or both sides of the package design onto a leadframe strip so as to create unique design features such as power and/or ground ring surrounding the die attach pad, interlocking rivet head construction for the contact pads, and an interlocking pattern for the die attach pad. After wire bonding and molding, a further etching is performed to isolate and expose contact pads. Singulation of individual chip packages from the leadframe strip is then performed by saw singulation or die punching.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: January 24, 2006
    Assignee: ASAT, Ltd.
    Inventors: Neil McLellan, Chun Ho Fan, Kwok Cheung Tsang, Kin Pui Kwan, Wing Him Lau
  • Patent number: 6987032
    Abstract: A ball grid array package is manufactured by mounting a semiconductor die to a first surface of a substrate and mounting a die adapter to the semiconductor die. The semiconductor die is wire bonded to ones of conductive traces of the substrate. A collapsible spacer is mounted to the substrate and the substrate is releasably clamped to an upper side of a mold cavity. A heat spreader and at least one collapsible spacer are placed in the mold cavity such that the collapsible spacer is disposed between the heat spreader and the substrate. A molding compound is molded in the mold, thereby molding the semiconductor die, the substrate, the wire bonds, the die adapter, the at least one collapsible spacer and the heat spreader into the molding compound to provide a molded package. A ball grid array is formed on a second surface of the substrate, bumps of the ball grid array being electrically connected to the conductive traces and the integrated circuit package is singulated.
    Type: Grant
    Filed: August 20, 2003
    Date of Patent: January 17, 2006
    Assignee: ASAT Ltd.
    Inventors: Chun Ho Fan, Wing Keung Lam, Ming Wang Sze, Sadak Thamby Labeeb, Neil McLellan, Mohan Kirloskar
  • Patent number: 6984785
    Abstract: A cavity-down ball grid includes a flexible circuit tape including a flexible tape laminated to a conductor layer. The flexible circuit tape has an aperture therein. A thermally conductive heat spreader is fixed to a first surface of the flexible circuit tape and the heat spreader has a cavity aligned with the aperture of the flexible circuit tape. A semiconductor die is mounted to the heat spreader in a die-down configuration in the cavity. A thermally conductive die adapter is fixed to the semiconductor die such that a portion of the die adapter protrudes from the cavity. A plurality of wire bonds connect the semiconductor die to bond sites on the second surface of the flexible circuit tape. An encapsulating material encapsulates the semiconductor die and the wire bonds and a plurality of solder balls are disposed on a second surface of the flexible circuit tape, in the form of a ball grid array.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: January 10, 2006
    Assignee: ASAT Ltd.
    Inventors: Qizhong Diao, Neil McLellan, Mohan Kirloskar
  • Patent number: 6982491
    Abstract: A process for fabricating an integrated circuit package includes: providing a substrate having conductive traces therein, the substrate including a cavity therein; mounting a semiconductor die to a first surface of the substrate, in a flip-chip orientation such that a sensor portion of the semiconductor die is aligned with the cavity and conductive interconnects connect pads of the semiconductor die to the conductive traces of the substrate; filling an area surrounding the interconnects with an underfill material; and mounting a plurality of conductive balls on the first surface of the substrate and in electrical connection with the conductive traces such that ones of the conductive balls are connected to ones of the pads of the semiconductor die via the conductive traces.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: January 3, 2006
    Assignee: ASAT Ltd.
    Inventors: Chun Ho Fan, Sadak Thamby Labeeb, Lap Keung Chow
  • Patent number: 6979594
    Abstract: A ball grid array package is manufactured by mounting a semiconductor die to a first surface of a substrate array. Wires are bonded between the semiconductor die and ones of conductive traces of the substrate array. The heat spreader is disposed in a mold and the substrate array is releasably clamped to a top die of the mold. The semiconductor die, the substrate array, the wire bonds and the heat spreader are molded into a molding material to provide a molded package. Next, the molded package is removed from the mold and a plurality of solder balls are added in the form of a ball grid array on a second surface of the substrate array such that bumps of the ball grid array are electrically connected to the conductive traces. The integrated circuit package is then singulated from a remainder of the substrate array.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: December 27, 2005
    Assignee: ASAT Ltd.
    Inventors: Chun Ho Fan, Sadak Thamby Labeeb, Ming Wang Sze
  • Patent number: 6964918
    Abstract: A process for fabricating an integrated circuit package includes establishing a plating mask on a first surface of a metal carrier. The plating mask defines a plurality of components including a die attach pad, at least one row of contact pads and at least one additional electronic component. A plurality of metallic layers are deposited on exposed portions of the first surface of the metal carrier. The plating mask is stripped from the metal carrier, leaving the plurality of metallic layers in the form of the plurality of components. A semiconductor die is mounted to die attach pad and pads of the semiconductor die are electrically connected to ones of the contact pads and to the additional electronic component. The first surface of the metal carrier is overmolded to encapsulate the plurality of components and the semiconductor die and the metal carrier is etched away.
    Type: Grant
    Filed: January 15, 2004
    Date of Patent: November 15, 2005
    Assignee: Asat Ltd.
    Inventors: Chun Ho Fan, Kwok Cheung Tsang
  • Patent number: 6946324
    Abstract: A process for fabricating a leadless plastic chip carrier includes laminating a first metal strip to a second metal strip to form a leadframe strip, selectively etching the first metal strip to define at least a row of contact pads, mounting a semiconductor die to either a die attach pad or the second metal strip and wire bonding the semiconductor die to ones of the contact pads, encapsulating a top surface of the leadframe strip in a molding material, removing the second metal strip, thereby exposing the die attach pad and the at least one row of contact pads, and singulating the leadless plastic chip carrier from the leadframe strip.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: September 20, 2005
    Assignee: Asat Ltd.
    Inventors: Neil McLellan, Chun Ho Fan, Kin Pui Kwan, Wing Him Lau
  • Patent number: 6933594
    Abstract: A leadless plastic chip carrier is constructed by half etching one or both sides of the package design onto a leadframe strip so as to create unique design features such as power and/or ground ring surrounding the die attach pad, interlocking rivet head construction for the contact pads, and an interlocking pattern for the die attach pad. After wire bonding and molding, a further etching is performed to isolate and expose contact pads. Singulation of individual chip packages from the leadframe strip is then performed by saw singulation or die punching.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: August 23, 2005
    Assignee: ASAT Ltd.
    Inventors: Neil McLellan, Chun Ho Fan, Kwok Cheung Tsang, Kin Pui Kwan, Wing Him Lau
  • Patent number: 6933176
    Abstract: A ball grid array integrated circuit package is manufactured by mounting a semiconductor die, to a surface of a substrate such that bumps on the semiconductor die are electrically connected to conductive traces of the substrate. At least one collapsible spacer is mounted to at least one of a heat spreader, the semiconductor die and the substrate. The heat spreader is fixed to the at least one of the first surface of the substrate and the semiconductor die such that he at least one collapsible spacer is disposed therebetween. A ball grid array is formed on a second surface of the substrate, bumps of the ball grid array being electrically connected to the conductive traces and the integrated circuit package is singulated.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: August 23, 2005
    Assignee: Asat Ltd.
    Inventors: Mohan Kirloskar, Chun Ho Fan, Neil McLellan
  • Patent number: 6903304
    Abstract: A process for reworking or dressing a saw blade used in wafer dicing and singulation of molded array integrated circuit packages, includes rotating the saw blade on a spindle and ablating an edge portion of the saw blade using a laser and thereby dressing the saw blade.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: June 7, 2005
    Assignee: Asat Ltd.
    Inventors: Neil McLellan, Chun Ho Fan, Geraldine Tsui Yee Lin, John Ping Sheung Lau
  • Patent number: 6872661
    Abstract: A leadless plastic chip carrier has a plurality of die attach pads on which a singulated semi-conductor die is mounted. At least one row of contact pads circumscribes the plurality of die attach pads and a power/ground ring is intermediate the contact pads and the die attach pads. Wire bonds connect the semiconductor die, the contact pads and the power/ground ring. An overmold covers the semi-conductor die, the die attach pads, the power/ground ring and the contact pads such that each of the die attach pads and the contact pads has one exposed surface.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: March 29, 2005
    Assignee: ASAT Ltd.
    Inventors: Kin Pui Kwan, Wing Him Lau, Kwok Cheung Tsang, Chun Ho Fan, Neil McLellan
  • Patent number: 6841859
    Abstract: A process for fabricating a cavity-type integrated circuit package. The process includes: supporting an interior portion of each of a plurality of leads, in a mold; supporting a die attach pad in said mold; molding a package body in said mold such that said leads extend from an interior cavity of said package body to an exterior thereof; mounting a semiconductor die to said die attach pad; wire bonding various ones of said leads to said semiconductor die; adding a fill material for covering at least a surface of said interior portion of said leads; and mounting a lid on said package body for enclosing said die in said cavity of said package body.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: January 11, 2005
    Assignee: Asat Ltd.
    Inventors: Labeeb Sadak Thamby, Neil McLellan, Hugo Chi Wai Wong, William Lap Keung Chow
  • Patent number: 6821817
    Abstract: A process for fabricating a cavity-type integrated circuit package. The process includes: supporting an interior portion of each of a plurality of leads, in a mold; supporting a die attach pad in said mold; molding a package body in said mold such that said leads extend from an interior cavity of said package body to an exterior thereof; mounting a semiconductor die to said die attach pad; wire bonding various ones of said leads to said semiconductor die; adding a fill material for covering at least a surface of said interior portion of said leads; and mounting a lid on said package body for enclosing said die in said cavity of said package body.
    Type: Grant
    Filed: September 3, 2002
    Date of Patent: November 23, 2004
    Assignee: ASAT Ltd.
    Inventors: Labeeb Sadak Thamby, Neil McLellan, Hugo Chi Wai Wong, William Lap Keung Chow