Patents by Inventor Julian P. Partridge

Julian P. Partridge 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: 5535936
    Abstract: A method, and product created thereby, by which low melting point solder suitable for reflow connection of components is formed on select fine pitch contacts of a printed circuit board. The method is particularly suited to the attachment of flip-chip die to printed circuit boards which also include coarse pitch surface mount components. Controlled volumes of solder are formed onto fine pitch contacts of the printed circuit board through selective holes in a mask formed onto the board. The deposit is accomplished by molten solder immersion preferably using conventional hot air solder level manufacturing equipment. The volume of solder is related to the thickness of the mask. The mask is then removed, the deposited low temperature solder is flattened, and the coarse pitch contacts are covered with solder paste in a conventional screening process. Flux is applied to the fine pitch contacts.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: July 16, 1996
    Assignee: International Business Machines Corporation
    Inventors: Ku H. Chong, Charles H. Crockett, Jr., Julian P. Partridge, Bhavyen S. Sanghavi
  • Patent number: 5492266
    Abstract: A method, and product created thereby, by which low melting point solder suitable for reflow connection of components is formed on select contacts of a printed circuit board. The method is particularly suited to the fabrication of populated printed circuit board having fine pitch devices including flip-chip devices, connected on a board including conventional coarse pitch surface mounted components. The fine pitch contacts of the board are exposed through holes in a stencil characterized in its ability to withstand solder reflow temperatures, not be wettable by solder, and have a coefficient of thermal expansion relatively matching the printed circuit board. Low temperature solder paste is screen deposited into the stencil openings. With the stencil fixedly positioned on the board, the solder paste retained by the stencil pattern is reflowed to selectively form on the underlying contacts of the printed circuit board.
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: February 20, 1996
    Assignee: International Business Machines Corporation
    Inventors: Karl G. Hoebener, Eric M. Hubacher, Julian P. Partridge
  • Patent number: 5493075
    Abstract: A method, and product created thereby, by which low melting point solder suitable for reflow connection of components is formed on select fine pitch contacts of a printed circuit board. The method is particularly suited to the attachment of flip-chip die to printed circuit boards which also include coarse pitch surface mount components. Controlled volumes of solder are formed onto fine pitch contacts of the printed circuit board through selective holes in a mask formed onto the board. The deposit is accomplished by molten solder immersion preferably using conventional hot air solder level manufacturing equipment. The volume of solder is related to the thickness of the mask. The mask is then removed, the deposited low temperature solder is flattened, and the coarse pitch contacts are covered with solder paste in a conventional screening process. Flux is applied to the fine pitch contacts.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: February 20, 1996
    Assignee: International Business Machines Corporation
    Inventors: Ku H. Chong, Charles H. Crockett, Jr., Julian P. Partridge, Bhavyen S. Sanghavi
  • Patent number: 5286417
    Abstract: A fusible conductive adhesive for making electrical and mechanical contact is provided. The fusible conductive adhesive contains a polymer having a glass transition temperature and a thermal expansion co-efficient. The thermal expansion co-efficient of the polymer is in the range of about 5 parts per million per degree centigrade to about 10 parts per million per degree centigrade along a z-axis. The polymer is loaded with a conductive material having a sintering temperature range overlapping the glass transition temperature of the polymer. In addition, the loading of the conductive material in the polymer is in the range of about 15% to about 20% conductive material by weight based on the total weight of the polymer and the conductive material.
    Type: Grant
    Filed: December 6, 1991
    Date of Patent: February 15, 1994
    Assignee: International Business Machines Corporation
    Inventors: Issa S. Mahmoud, Julian P. Partridge
  • Patent number: 5141602
    Abstract: An apparatus and method for plating metal on a conductor and/or across gaps on insulating substrates is described incorporating two probes, a probe positioner, first circuitry for applying alternating-current electrical power wherein the magnitude of the voltage is controlled as a function of time, and second circuitry for applying alternating-current electrical power wherein the magnitude of the current is controlled as a function of time. The invention overcomes the problem of providing an automatic apparatus for reliably repairing defective wiring or completing seeded sections of wiring having a wide range of initial thermal and electrical characteristics.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: August 25, 1992
    Assignee: International Business Machines Corporation
    Inventors: Chengjun J. Chen, Richard I. Kaufman, Julian P. Partridge