Patents by Inventor Sankaranarayanan Ganesan

Sankaranarayanan Ganesan 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).

  • Method for making a moisture resistant semiconductor device having an organic substrate
    Patent number: 5756380
    Abstract: A method for making moisture resistant semiconductor devices having organic substrates targets each of the potentially critical interfaces within a semiconductor device having the potential for delamination and cracking. An organic substrate (110) is designed to include a solid pad (116) having a chemically created oxide layer (118) formed thereon. A silicone-based die attach material (108) is dispensed and gelled very soon after dispensing to prevent excessive bleed. A semiconductor die (102) is mounted to the substrate after undergoing a cleaning operation to remove contaminants from the backside of the die. Prior to molding compound encapsulation and subsequent to die attach material cure, the substrate is cleaned to improve adhesion to the die attach material fillet (122).
    Type: Grant
    Filed: November 2, 1995
    Date of Patent: May 26, 1998
    Assignee: Motorola, Inc.
    Inventors: Howard M. Berg, Sankaranarayanan Ganesan, Gary L. Lewis, George W. Hawkins, James W. Sloan, Scott C. Bolton
  • Method and apparatus for improving interfacial adhesion between a polymer and a metal
    Patent number: 5554569
    Abstract: A leadframe (11) and a method for improving adhesion of a polymer (17, 19) to the leadframe (11). The leadframe (11) has a flag (14) having a top surface (15) and a bottom surface (18), and leads (12). Microscopic locking features (31) are formed in the top surface (15) and the bottom surface (18) of flag (14) by bombarding the flag (14) with a grit material. Thus, the top and bottom surfaces (14, 18) are roughened. A semiconductor die (13) is attached to the flag (14) by a die attach material (17) and the flag (13), the semiconductor material (13), and portions of the leads (12) are encapsulated by a molding compound. The pits improve the adhesion of the die attach material (17) and the molding compound (19) to the leadframe (11).
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: September 10, 1996
    Assignee: Motorola, Inc.
    Inventors: Sankaranarayanan Ganesan, Howard M. Berg
  • Method of characterizing the level of cleanliness of an inorganic surface
    Patent number: 5275667
    Abstract: A fast and simple method of determining a desired level of cleanliness of an inorganic surface is performed by correlating a level of cleanliness of many inorganic surfaces having varying thicknesses of organic contamination with reliability tests. The level of cleanliness is in terms of a measurement from a water drop test. The level of cleanliness between two inorganic surfaces can also be compared by utilizing the combination of a UV/ozone clean and the level of cleanliness to determine the relative amount of contamination present on one inorganic surface as compared to the other.
    Type: Grant
    Filed: May 4, 1992
    Date of Patent: January 4, 1994
    Assignee: Motorola, Inc.
    Inventors: Sankaranarayanan Ganesan, Shun-Meen Kuo, Howard M. Berg