Patents by Inventor Shaw Wei Lee

Shaw Wei Lee 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: 8093707
    Abstract: Various semiconductor package arrangements and methods that improve the reliability of wire bonding a die to ground or other outside contacts are described. In one aspect, selected ground pads on the die are wire bonded to a bonding region located on the tie bar portion of the lead frame. The tie bar is connected to an exposed die attach pad that is downset from the bonding region of the tie bar. In some embodiments, the bonding region and the leads are at substantially the same elevation above the die and die attach pad. The die, bonding wires, and at least a portion of the lead frame can be encapsulated with a plastic encapsulant material while leaving a contact surface of the die attach pad exposed to facilitate electrically coupling the die attach pad to an external device.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: January 10, 2012
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Ein Sun Ng, Chue Siak Liu, Lee Han Meng @ Eugene Lee, Yee Kim Lee
  • Publication number: 20110140253
    Abstract: A variety of semiconductor package arrangements and packaging methods are described that improve the reliability of bonding wires that down bond a die to a die attach pad. In one aspect, selected portions of the top surface of a lead frame (which may be in panel form) are plated (e.g., silver plated) to facilitate wire bonding. The plating covers some, but not all of a die attach surface of the die attach pad. In some preferred embodiments, the plating on the die attach pad is arranged as a peripheral ring that surrounds an unplated central region of the die support surface. In other embodiments, the plating on the die attach pad takes the form of bars or other geometric patterns that do not fully cover the die support surface. Unplated portions of the die support surface are roughened to improve the adherence of the die to the die attach pad, thereby reducing the probability of die attach pad delamination and the associated risks to down bonded bonding wires.
    Type: Application
    Filed: December 14, 2009
    Publication date: June 16, 2011
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Shaw Wei LEE, Yee Kim LEE, Ein Sun NG, Lee Han Meng @ Eugene LEE, Ting Soon Peter CHIN
  • Publication number: 20110089556
    Abstract: Various semiconductor package arrangements and methods that improve the reliability of wire bonding a die to ground or other outside contacts are described. In one aspect, selected ground pads on the die are wire bonded to a bonding region located on the tie bar portion of the lead frame. The tie bar is connected to an exposed die attach pad that is downset from the bonding region of the tie bar. In some embodiments, the bonding region and the leads are at substantially the same elevation above the die and die attach pad. The die, bonding wires, and at least a portion of the lead frame can be encapsulated with a plastic encapsulant material while leaving a contact surface of the die attach pad exposed to facilitate electrically coupling the die attach pad to an external device.
    Type: Application
    Filed: October 19, 2009
    Publication date: April 21, 2011
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Shaw Wei LEE, Ein Sun NG, Chue Siak LIU, Lee Han Meng Eugene LEE, Yee Kim LEE
  • Patent number: 7846775
    Abstract: Techniques for forming micro-array style packages are disclosed. A matrix of isolated contact posts are placed on an adhesive carrier. Dice are then mounted (directly or indirectly) on the carrier and each die is electrically connected to a plurality of associated contacts. The dice and portions of the contacts are then encapsulated in a manner that leaves at least bottom portions of the contacts exposed to facilitate electrical connection to external devices. The encapsulant serves to hold the contacts in place after the carrier has been removed.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: December 7, 2010
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Nghia Thuc Tu, Sadanand R. Patil
  • Patent number: 7795126
    Abstract: A semiconductor device of the invention includes an integrated circuit formed on a semiconductor substrate having first and second surfaces and a notch region along the edges. The first surface includes electrical contact pads electrically connected with the integrated circuit. The first surface of the semiconductor substrate includes a top protective layer that has a surface portion extending beyond the edges of the semiconductor substrate. The second surface of the semiconductor substrate includes a bottom protective layer with electrical connectors. The surface portion of the top protective layer includes electrical contact pads that are electrically interconnected with electrical contact pad extensions. The electrical contact pad extensions are interconnected with electrical connectors via a backside electrical connector that overlaps the electrical contact pad extensions forming a lap connection. Methods for constructing such devices and connections are also disclosed.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: September 14, 2010
    Assignee: National Semiconductor Corporation
    Inventors: Ashok Prabhu, Sadanand R. Patil, Shaw Wei Lee, Alexander H. Owens
  • Patent number: 7419855
    Abstract: A method and apparatus for making reliable miniature semiconductor packages having a reduced height and footprint is provided. The package includes a semiconductor chip having an active surface and a non-active surface and one or more contacts positioned adjacent the semiconductor chip. Electrical connections are formed between the contacts and the semiconductor chip. An adhesive tape provided adjacent the non-active surface of the semiconductor chip and the one or more contacts positioned adjacent the semiconductor chip. An adhesive material provided between the non-active surface of the chip and the adhesive tape.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: September 2, 2008
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Nghia Thuc Tu, Santhiran S/O Nadarajah, Lim Peng Soon
  • Patent number: 7340181
    Abstract: A semiconductor device of the invention includes an integrated circuit formed on a semiconductor substrate having first and second surfaces and a notch region along the edges. The first surface includes electrical contact pads electrically connected with the integrated circuit. The first surface of the semiconductor substrate includes a top protective layer that has a surface portion extending beyond the edges of the semiconductor substrate. The second surface of the semiconductor substrate includes a bottom protective layer with electrical connectors. The surface portion of the top protective layer includes electrical contact pads that are electrically interconnected with electrical contact pad extensions. The electrical contact pad extensions are interconnected with electrical connectors via a backside electrical connector that overlaps the electrical contact pad extensions forming a lap connection. Methods for constructing such devices and connections are also disclosed.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: March 4, 2008
    Assignee: National Semiconductor Corporation
    Inventors: Ashok Prabhu, Sadanand R. Patil, Shaw Wei Lee, Alexander H. Owens
  • Patent number: 7205095
    Abstract: An method and apparatus for fabricating a die having imaging circuitry and fabricating a lid having a transparent region and support regions having a predetermined height. The lid is fabricated by applying a photo-sensitive adhesive layer with a thickness substantially equal to the predetermined height to a transparent plate and patterning the photo-sensitive adhesive layer to form the transparent region and the support regions. Once fabrication of the lid is complete, it is mounted directly onto the die so that the transparent region generally covers the imaging circuitry. The resulting apparatus includes a lid mounted directly onto the die with the transparent region generally positioned above the imaging circuitry. A gap, having a height dimension substantially equal to the predetermined height of the support regions of the lid, is spaced between the transparent region of the lid and the imaging circuitry on the die.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: April 17, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Ashok Prabhu, Shaw Wei Lee
  • Patent number: 7161232
    Abstract: A method and apparatus for making reliable miniature semiconductor packages having a reduced height and footprint is provided. The package includes a semiconductor chip having an active surface and a non-active surface and one or more contacts positioned adjacent the semiconductor chip. Electrical connections are formed between the contacts and the semiconductor chip. An adhesive tape provided adjacent the non-active surface of the semiconductor chip and the one or more contacts positioned adjacent the semiconductor chip. An adhesive material provided between the non-active surface of the chip and the adhesive tape.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: January 9, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Nghia Thuc Tu, Santhiran S/O Nadarajah, Lim Peng Soon
  • Patent number: 7087986
    Abstract: A solder pad configuration for use in an IC package is described. Various embodiments of the invention describe IC packages, lead-frames, or substrate panels configured with generally noncircular solder pads at their bottom surfaces. The noncircular shapes allow for greater surface area than circular solder pads having diameters equal to a major dimension of the noncircular shapes, while maintaining the same metal-to-metal clearance between the pads and adjacent leads. This increased surface area provides for stronger and more reliable solder joints.
    Type: Grant
    Filed: June 18, 2004
    Date of Patent: August 8, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Jaime A. Bayan, Ashok S. Prabhu, Shaw Wei Lee
  • Patent number: 6933212
    Abstract: A method and apparatus for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer without the use of a wafer saw. The method includes forming trenches along the scribe lines on a semiconductor wafer and then applying a mechanical pressure to the semiconductor wafer. The mechanical pressure causes a “clean break” of the wafer along the scribe lines, thereby singulating individual die on the wafer. The apparatus comprises a pad for supporting a semiconductor wafer and a positioning member to position the semiconductor wafer on the pad. A pressure mechanism is provided to apply a mechanical pressure to the wafer so as to singulate the individual die on the wafer.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: August 23, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Nghia T. Tu, Sadanand Patil, Visvamohan Yegnashankaran
  • Patent number: 6873024
    Abstract: An apparatus and method for wafer level packaging of optical imaging die using conventional semiconductor packaging techniques. The method comprises forming spacing structures over imaging circuitry on a plurality of dice on a semiconductor wafer, attaching a transparent template on the spacing structures on the plurality dice on the semiconductor wafer, singulating the plurality of dice on the semiconductor wafer, and packaging the plurality of dice after being singulated from the wafer. The apparatus comprises a semiconductor wafer including a plurality of dice, each of the dice including imaging circuitry and bond pads. A translucent template is positioned over the semiconductor wafer. The translucent plate includes die cover regions configured to cover the imaging circuitry of the dice and recess regions to exposed the bond pads of the dice respectively.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: March 29, 2005
    Assignee: Eastman Kodak Company
    Inventors: Ashok Prabhu, Shaw Wei Lee
  • Patent number: 6723585
    Abstract: A variety of leadless packaging arrangements and methods of packaging integrated circuits in leadless packages are disclosed. The described lead frames are generally arranged such that each device area has a plurality of contacts but no die attach pad. With this arrangement, the back surface of the die is exposed and coplanar with the exposed bottom surface of the contacts. A casing material (typically plastic) holds the contacts and die in place. In one aspect of the invention, the back surface of the die is metallized. The metallization forms a good attachment surface for the package and serves as a good thermal path to transfer heat away from the die. In another aspect, at least some of the contacts have a top surface, a shelf, and a bottom surface. The die is wire bonded (or otherwise electrically connected) to the shelf portions of the contacts. The described package is quite versatile.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: April 20, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Nghia Tu, Shaw Wei Lee, Sadanand R. Patil
  • Patent number: 6551859
    Abstract: Techniques for improving the manufacture and structure of leadframe chip scale packages and land grid array packages are described. One aspect of the invention pertains to a method for patterning a conductive substrate, which is utilized to form a packaged semiconductor device, wherein a metallic barrier layer and a second metallic layer are utilized as an etching resist. A method, according to another aspect of the invention pertains to covering a metallic barrier layer and second metallic layer with a etch resistant cap such that the etch resistant cap is used as a etching resist. In another aspect of the present invention, a method for treating a conductive leadframe with a CZ treatment is disclosed. In yet another aspect of the present invention, techniques relating to locking grooves within the studs of a studded leadframe are disclosed.
    Type: Grant
    Filed: February 22, 2001
    Date of Patent: April 22, 2003
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Thanh Lequang, Wayne W. Lee, Glenn Narvaez, William Jeffery Schaefer
  • Patent number: 6396135
    Abstract: A number of techniques and substrate arrangements are described that working individually and in common have been found to significantly improve the environmental resistance of the resulting package. In one aspect, conductive pads (referred to herein as landing pads) on the top surface of a substrate are slightly undercut. This permits molding material applied during later packaging to flow into the undercut regions to help improve adhesion between the substrate and the molding material. In another aspect, metallic die attach pads formed on the substrate are patterned to provide better adhesion between the substrate and a solder mask that covers the die attach pads. More specifically, the metallic die attach pads are patterned to have a number of opening defined therein that leave corresponding portions of the substrate exposed.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: May 28, 2002
    Assignee: National Semiconductor Corporation
    Inventors: Glenn C. Narvaez, Shaw Wei Lee
  • Patent number: 6362530
    Abstract: A method of forming an integrated circuit package includes providing a flip chip integrating circuit die having a first plurality of contacts for electrically connecting the die to other elements. A second plurality of contacts for electrically connecting the integrated circuit package to external elements is also provided. A substrate for supporting the flip chip die and the second plurality of contacts is initially prepared. The substrate includes a connecting arrangement for electrically connecting the first plurality of contacts on the die to the second plurality of contacts. The method includes the step positioning the flip chip integrated circuit die and the second plurality of contacts on the substrate.
    Type: Grant
    Filed: April 6, 1998
    Date of Patent: March 26, 2002
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Hem P. Takiar
  • Patent number: 6284566
    Abstract: An assembly process provides a chip scale package (CSP) which characteristically includes (i) a perforated substrate in which vias can be embedded, (ii) a solder mask on which the integrated circuit die can be attached, and (iii) efficient use of the surface area for electrically routing signals from the integrated circuit die to the external terminals attached to the perforated substrate. The resulting package is highly compact and therefore has a foot print minimally larger than the surface area of the integrated circuit chip. Consequently, the costs of substrate and capsulation materials are minimized. The assembly process allows very high volume production because a large number of integrated circuits can be made on a single unit of the substrate, and singulation is performed in the assembly process at a stage much later than the corresponding stage in a conventional process.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: September 4, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Hem P. Takiar, Ranjan J. Mathew
  • Patent number: 6278618
    Abstract: A variety of improved substrate structures and substrate fabrication techniques for use in integrated circuit packaging are described. In one aspect, a substrate strip fabrication technique that facilitates strip testing of the dice mounted thereon is described. The described technique works well even when landings on the substrate are electrolytically plated. In a preferred embodiment, the substrate is formed in a manner that facilitates the use of non-stick detection during wire bonding. In a distinct aspect of the invention the substrate strip has a plurality of distinct molding area tiles that each have a two dimensional array of substrate segments formed thereon. The substrate segments each have a die attach area, a plurality of landing one surface and a plurality of contact pads on the other. The contact pads are positioned substantially across from the landings and are electrically connected thereto by associated vias.
    Type: Grant
    Filed: October 14, 1999
    Date of Patent: August 21, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Anindya Poddar, Ram Veeraraghavan, Thanh Lequang
  • Patent number: 6173490
    Abstract: A method and an apparatus for forming a panel of packaged integrated circuits is disclosed. A substrate panel having an array of integrated circuits mounted thereon is placed in a mold having a molding chamber. The molding chamber has a multiplicity of adjacent package recesses flowably interconnected by way of a plurality of molding compound flowgates. Each package recess is suitable for receiving at least one associated integrated circuits. A molding compound is passed into the molding chamber by way of a mold gate such that at least some of the molding compound passes through a plurality of different package recesses by way of their associated flowgates. In one embodiment, the mold includes a mold body having a molding chamber with a plurality of ridges that define the multiplicity of package recesses within the molding chamber. The multiplicity of package recesses are flowably interconnected through flowgates formed by the ridges.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: January 16, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Hem P. Takiar, Fred Drummond
  • Patent number: 6140708
    Abstract: An assembly process provides a chip scale package (CSP) which characteristically includes (i) a perforated substrate in which vias can be embedded, (ii) a solder mask on which the integrated circuit die can be attached, and (iii) efficient use of the surface area for electrically routing signals from the integrated circuit die to the external terminals attached to the perforated substrate. The resulting package is highly compact and therefore has a foot print minimally larger than the surface area of the integrated circuit chip. Consequently, the costs of substrate and capsulation materials are minimized. The assembly process allows very high volume production because a large number of integrated circuits can be made on a single unit of the substrate, and singulation is performed in the assembly process at a stage much later than the corresponding stage in a conventional process.
    Type: Grant
    Filed: July 8, 1997
    Date of Patent: October 31, 2000
    Assignee: National Semiconductor Corporation
    Inventors: Shaw Wei Lee, Hem P. Takiar, Ranjan J. Mathew