Patents Assigned to Philip A. Hunt Chemical Corp.
  • Patent number: 4319955
    Abstract: An improved ammoniacal alkaline etchant solution and method of reducing etchant undercut for use in etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, which reduces the amount of undercutting beneath the resist-coated areas that lie above the copper traces. The improved etchant solution contains an organic undercut inhibitor which can be either 5-nitro-1H indazole or pyrazole and the improved method includes the step of incorporating said organic undercut inhibitor in a standard ammoniacal alkaline cupric etchant solution. The organic undercut inhibitor causes the formation of a bath-insoluble, physically weak, etch-resistant film on the copper substrate. Said film serves to protect the side walls of an etched depression and thereby diminishes undercutting.
    Type: Grant
    Filed: November 5, 1980
    Date of Patent: March 16, 1982
    Assignee: Philip A. Hunt Chemical Corp.
    Inventor: Kenneth J. Murski
  • Patent number: 4311551
    Abstract: An alkaline copper etching working bath for dissolving copper containing an etch accelerating additive selected from the group consisting of cyanamide and its precursors. The accelerating additives when added to the alkaline copper etching bath increase the etch rate and reduce undercut. The bath includes cupric ions, an ammonium salt such as a chloride and/or a carbonate, ammonium hydroxide to achieve a pH greater than 7, water, and the etch accelerating additive. The invention includes etching baths, methods for their use, the preparation of a certain etch accelerating additive and the provision of certain cyanamide precursors.
    Type: Grant
    Filed: July 15, 1980
    Date of Patent: January 19, 1982
    Assignee: Philip A. Hunt Chemical Corp.
    Inventor: Donald J. Sykes
  • Patent number: 4298681
    Abstract: An N,N, disubstituted p-phenylenediamine salt of a phosphoric acid selected from the group consisting of ortho-phosphoric acid, pyrophosphoric acid and polyphosphoric acid. Such a phosphate is incorporated as a color developing agent in a liquid packaged developer concentrate which subsequently is mixed with other materials contained in a multi-package receptacle and the mixture is diluted with water to form a color developer working solution (bath) for developing a colored film. The developer concentrate has the advantage that the color developing agent therein does not tend to deteriorate upon standing, as do present-day widely used commercial N,N, disubstituted p-phenylenediamine color developing agents in developer liquid concentrates, e.g.
    Type: Grant
    Filed: February 23, 1973
    Date of Patent: November 3, 1981
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: David K. Bulloch, Hong Z. Kim
  • Patent number: 4268597
    Abstract: A method, apparatus and composition for developing an electric field image associated with the surface of an object by disposing said surface close to but out of contact with a surface of a liquid developer at a development zone. An electric field is in the configuration of an image. The magnitude of the electric field, and the distance between the surface of the object and the liquid surface at the development zone are such that at the development zone the electric field at or approaching the zone, with or without the assistance of an external electric field, segmentally raises closely spaced tiny amorphous (individually non-image-defining) pseudopods from the liquid developer surface toward the surface of the object. The pseudopods rise from the liquid surface under the influence of a segment of the electric field image and the tips of the pseudopods and/or droplets separated from these tips arrive at the surface of the object under the influence of the same field.
    Type: Grant
    Filed: April 16, 1979
    Date of Patent: May 19, 1981
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: Irving L. Klavan, Peter J. Calabrese, Theron R. Finch, Arthur Greenberg, Robert P. McElroy
  • Patent number: 4202620
    Abstract: An apparatus for developing a latent electrostatic image by passing the image close to but out of contact with a surface of a liquid developer at a development zone. The values of the magnitude of the charge of the image, the distance between the image segment and the liquid surface at the development zone, and the physical characteristics of the liquid are such that at the development zone the electrostatic field created by the segment of the image at the zone, with or without the assistance of an external electrostatic field impressed upon the development zone, raises pseudopods from the liquid developer surface which extend toward the carrier on which the electrostatic image is present. The pseudopods and/or droplets separated from the tip of the pseudopods surface under the influence of the electrostatic field created by the image segment, but are opposed by gravity.
    Type: Grant
    Filed: June 29, 1978
    Date of Patent: May 13, 1980
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: Irving L. Klavan, Peter J. Calabrese, Theron R. Finch, Arthur Greenberg, Robert P. McElroy
  • Patent number: 4202913
    Abstract: A method for developing a latent electrostatic image by passing the image close to but out of contact with a surface of a liquid developer at a development zone. The values of the magnitude of the charge of the image, the distance between the image segment and the liquid surface at the development zone, and the physical characteristics of the liquid are such that at the development zone the electrostatic field created by the segment of the image at the zone, with or without the assistance of an external electrostatic field impressed upon the development zone, raises pseudopods from the liquid developer surface which extend toward the carrier on which the electrostatic image is present. The pseudopods and/or droplets separated from the tips of the pseudopods leave the liquid surface under the influence of the electrostatic field created by the image segment.
    Type: Grant
    Filed: June 20, 1978
    Date of Patent: May 13, 1980
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: Irving L. Klavan, Peter J. Calabrese, Theron R. Finch, Arthur Greenberg, Robert P. McElroy
  • Patent number: 4191575
    Abstract: A two-step black and white photographic process in which conventional black and white developing of latent images in a silver halide black and white emulsion first is carried out and then, instead of simply fixing the developed emulsions containing black and white images, the emulsions are fixed and bleached concurrently for a short period of time long enough to perform the fixing and to enable a controlled mild degree of bleaching to occur. Such bleaching is carried out only for a time long enough selectively to attack low-density areas of freshly developed black and white images at a greater rate than areas of heavier density so as to depress the toe of the D log E curve without markedly affecting the balance of the curve, thus enhancing the images by obtaining a general increase of contrast, a reduction or total elimination of fog and a reduction or elimination of film haze, this latter being applicable primarily to radiology.
    Type: Grant
    Filed: August 3, 1976
    Date of Patent: March 4, 1980
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: Donald J. Sykes, Louis D. Pratt
  • Patent number: 4161406
    Abstract: A high speed color reversal cine film with latent images recorded thereon is so processed as to color-develop the latent images and concurrently reduce the high contrast at the dark end of the tone scale which is inherent in the prior art development of such film. The new method utilizes in the color developer bath increased amounts (in comparison with prior art color developer baths) of a competing coupler such as citrazinic acid and of a silver halide solvent such as ethylene diamine and reduces the amount of a reversal agent such as t-butylamine borane, and also includes a competing non-coupling developer such as 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone, or phenidone, or a derivative thereof.
    Type: Grant
    Filed: December 7, 1977
    Date of Patent: July 17, 1979
    Assignee: Philip A. Hunt Chemical Corp.
    Inventor: David K. Bulloch
  • Patent number: 4147581
    Abstract: An improvement in an etching process in which the etched product, the surface of which is covered with a film of aqueous etching liquid containing ions of the material etched, is rinsed with an aqueous liquid and the resulting liquid, now containing said ions in dilute concentration, is passed through an ion exchanger to selectively remove the ions from the rinse liquid which thereupon can be reused or discharged, without ecological damage, from the ion exchanger. The ion exchanger when laden with such ions is regenerated by passage therethrough of at least a portion of an etcher make-up aqueous replenishing solution which contains a zero or low concentration of said ions. The resulting replenishing solution portion, now containing a small concentration of these ions, is passed to the etcher, e.g., to the etcher sump.
    Type: Grant
    Filed: September 14, 1977
    Date of Patent: April 3, 1979
    Assignee: Philip A. Hunt Chemical Corp.
    Inventor: Warren A. Nelson