Patents Examined by Cynthia H. Hamilton
  • Patent number: 4657839
    Abstract: Improved resolution in a low cost non-critical photopolymer printing process is achieved by a non-volatile liquid image quality photopolymer layer disposed with air free surfaces sandwiched between two carrier surfaces, one being transparent and carrying a transparency image in contact with the liquid photopolymer to be exposed by radiation to cure the layer and produce the image pattern. In a typical example, paste-consistency photopolymer is imaged onto printed wiring boards by coating the board overall and positioning the photographic film over the board in register and off-contact. A resilient blade is pressed against the phototool at one end of the board and drawn across the surface, thus forcing the photographic film into intimate contact with the photopolymer and purging all air therebetween.
    Type: Grant
    Filed: August 25, 1983
    Date of Patent: April 14, 1987
    Inventor: Donald F. Sullivan