Patents Examined by M. Elve
  • Patent number: 5851311
    Abstract: A polymer-based solder paste composition having the strength and corrosion resistance of joints produced by conventional solder technology and the environmental and processing advantages of ICA technology comprises a powdered solder metal with a single component (single package) polymerizable flux composition. The polymerizable flux composition includes 55%-65% by weight of an epoxy such as epoxy novolac, the diglycidyl ethers of bisphenol A and F, and mixtures thereof, 0-15% by weight of a dicarboxylic acid, 9%-11% by weight of a polyalcohol, 3%-5% by weight of an amine thermal curing agent, and the balance including a chelating agent, a defoamer, a thixotrope and a surfactant. Upon heating, the solder metal spontaneously segregates from the flux composition, fuses, and forms a metallurgical joint, while the single-component polymerizable flux composition encapsulates the fused metal in a polymer coating which remains firm but pliable at reflow temperatures.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: December 22, 1998
    Assignee: Sophia Systems Co., Ltd.
    Inventors: Joram Diamant, Henry L. Myers