Patents by Inventor Dwadasi H. R. Sarma

Dwadasi H. R. Sarma 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).

  • Thick film sense resistor composition and method of using the same
    Patent number: 5221644
    Abstract: Disclosed is a thick film sense resistor composition containing palladium and silver in a weight ratio of about 56/44 to about 60/40 and a specific glass frit composition so that the sense resistor achieves low resistivity and controlled TCR.
    Type: Grant
    Filed: December 13, 1991
    Date of Patent: June 22, 1993
    Assignee: Delco Electronics Corporation
    Inventors: Carl W. Berlin, Dwadasi H. R. Sarma
  • Controlled adhesion conductor
    Patent number: 5176853
    Abstract: Compositions useful for printing controllable adhesion conductive patterns on a printed circuit board include finely divided copper powder, a screening agent and a binder. The binder is designed to provide controllable adhesion of the copper layer formed after sintering to the substrate so that the layer can lift off the substrate in response to thermal stress. Additionally, the binder serves to promote good cohesion between the copper particles to provide good mechanical strength to the copper layer so that it can tolerate lift off without fracture.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: January 5, 1993
    Assignee: Delco Electronics Corporation
    Inventors: Dwadasi H. R. Sarma, Ponnusamy Palanisamy, John A. Hearn, Dwight L. Schwarz
  • Method of achieving selective inhibition and control of adhesion in thick-film conductors
    Patent number: 5122929
    Abstract: A technique for providing controlled adhesion of a portion of a printed conductor to a circuit board employs an inhibitor layer between the circuit board and the portion of the printed conductor where such controlled adhesion is desired. The inhibitor layer is formed using a mixture of finely divided alumina powder and a glass frit, which are both suspended in an organic screening agent. An electrical module connected between controllably adherent conductor portions is thereby able to move to relative mechanical stresses.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: June 16, 1992
    Assignee: Delco Electronics Corporation
    Inventors: Ponnusamy Palanisamy, Dwadasi H. R. Sarma, John A. Hearn, Dwight L. Schwarz
  • Controlled adhesion conductor
    Patent number: 5121298
    Abstract: Compositions useful for printing controllable adhesion conductive patterns on a printed circuit board include finely divided copper powder, a screening agent and a binder. The binder is designed to provide controllable adhesion of the copper layer formed after sintering to the substrate so that the layer can lift off the substrate in response to thermal stress. Additionally, the binder serves to promote good cohesion between the copper particles to provide good mechanical strength to the copper layer so that it can tolerate lift off without fracture.
    Type: Grant
    Filed: July 13, 1990
    Date of Patent: June 9, 1992
    Assignee: Delco Electronics Corporation
    Inventors: Dwadasi H. R. Sarma, Ponnusamy Palanisamy, John A. Hearn, Dwight L. Schwarz
  • Ceramic hybrid integrated circuit having surface mount device solder stress reduction
    Patent number: 4959751
    Abstract: A printed circuit board assembly uses a conductive pattern that includes both firmly adherent conductors and controllably adherent conductors. The controllably adhering conductors are free to lift off the printed circuit board to relieve mechanical forces caused by thermal stresses at solder joints between the controllably adherent conductors and integrated circuit chips of the assembly.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: September 25, 1990
    Assignee: Delco Electronics Corporation
    Inventors: John A. Hearn, Dwight L. Schwarz, Dwadasi H. R. Sarma, Ponnusamy Palanisamy