Patents by Inventor Abraham B. Cohen
Abraham B. Cohen 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).
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Patent number: 5196136Abstract: A cleaning composition is disclosed which is suitable for cleaning substrates and particularly for cleaning flux residues from a printed circuit board. The cleaning composition comprises a hydrocarbon component, a compatibilizing agent, a multibasic ester additive, and optionally water. The multibasic ester may be an alkanoic acid ester of a diol or polyol, an alkanoic acid ester of a hydroxy alkanoate alkyl ester, or and alkyl ester of a compound containing two or more carboxylic acid groups and one or more hydroxyl groups which are optionally esterified with an alkanoic acid group. The cleaning composition may be used as a solution or as an emulsion or dispersion to clean a substrate.Type: GrantFiled: June 20, 1991Date of Patent: March 23, 1993Assignee: E. I. Du Pont de Nemours and CompanyInventors: Kenneth T. Dishart, Harold L. Jackson, Abraham B. Cohen, deceased
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Patent number: 5112726Abstract: The invention is directed to a laminate for the preparation of printed circuits by electroless plating of conductive metal thereon which comprisesa. an electrically insulative substrate bearingb. an adherent layer of crosslinked polymeric adhesive, which is insoluble in photodielectric developing solutions, having partially embedded therein finely divided particles of adsorbent which protrude from the adhesive surface away from the substrate, the protrusive surfaces of which are adsorptive with respect to electroless plating catalysts or reductive precursors thereof, andc. a solid layer of photodielectric adherently overlying the layer of adhesive and adsorbent particles.Type: GrantFiled: June 6, 1989Date of Patent: May 12, 1992Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Roxy N. Fan, John A. Quinn
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Patent number: 5002855Abstract: An integral three-dimensional object is formed from a photohardenable liquid composition containing radiation deflecting matter.Type: GrantFiled: April 21, 1989Date of Patent: March 26, 1991Assignee: E. I. Du Pont de Nemours and CompanyInventors: Roxy N. Fan, Abraham B. Cohen
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Patent number: 4859571Abstract: The invention is directed to a laminate for the preparation of printed circuits by electroless plating of conductive metal thereon which comprisesa. an electrically insulative substrate bearingb. an adherent layer of crosslinked polymeric adhesive, which is insoluble in photodielectric developing solutions, having partially embedded therein finely divided particles of adsorbent which protrude from the adhesive surface away from the substrate, the protrusive surfaces of which are adsorptive with respect to electroless plating catalysts or reductive precursors thereof, andc. a solid layer of photodielectric adherently overlying the layer of adhesive and adsorbent particles.Type: GrantFiled: December 30, 1986Date of Patent: August 22, 1989Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Roxy Fan, John A. Quinn
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Patent number: 4737446Abstract: The invention is directed to a laminate for the preparation of a multilayer printed circuit by electroless plating of conductive metal thereon which comprisesa. a substrate having formed on a surface thereofb. a conductive pattern, and,c. overlying the pattern and surrounding substrate areas, a layer of tonable photodielectric material having partially embedded therein finely divided particles of adsorbent which protrude from the layer surface away from the substrate, the protrusive surfaces of which are adsorptive with respect to electroless plating catalysts or reductive precursors thereof.Type: GrantFiled: December 30, 1986Date of Patent: April 12, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Roxy N. Fan, John A. Quinn
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Patent number: 4698294Abstract: Lamination of a photopolymerizable film onto a substrate employs an intermediate nonphotosensitive liquid which is substantially all monomer.Type: GrantFiled: September 12, 1986Date of Patent: October 6, 1987Assignee: E. I. Du Pont de Nemours and CompanyInventors: Tit-Kueng Lau, Abraham B. Cohen
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Patent number: 4668604Abstract: Photosensitive coating composition consisting essentially of an ethylenic unsaturated compound, a photoinitiator or photoinitiator system, an organic polymeric binder, discrete, substantially nonswellable, nonagglomerating, crosslinked beads, 0.1 to 4.0 .mu.m in average diameter size, at least 90% of the beads by population below 6.0 .mu.m, as defined and a solvent for the binder. The crosslinked beads can be present in positive-working systems. Preferred beads are trimethylolpropane triacrylate. The coating composition can be dried quickly into the form of a film which is useful as a dry film photoresist.Type: GrantFiled: April 11, 1986Date of Patent: May 26, 1987Assignee: E.I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Vincent J. Webers
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Patent number: 4601970Abstract: Photosensitive coating composition consisting essentially of an ethylenic unsaturated compound, a photoinitiator or photoinitiator system, an organic polymeric binder, discrete, substantialy nonswellable, nonagglomerating, crosslinked beads, 0.1 to 4.0 .mu.m in average diameter size, at least 90% of the beads by population below 6.0 .mu.m, as defined and a solvent for the binder. The crosslinked beads can be present in positive-working systems. Preferred beads are trimethylolpropane triacrylate. The coating composition can be dried quickly into the form of a film which is useful as a dry film photoresist.Type: GrantFiled: July 19, 1985Date of Patent: July 22, 1986Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Vincent J. Webers
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Patent number: 4551415Abstract: Photosensitive coating composition consisting essentially of an ethylenic unsaturated compound, a photoinitiator or photoinitiator system, an organic polymeric binder, discrete, substantially nonswellable, nonagglomerating, crosslinked beads, 0.1 to 4.0 .mu.m in average diameter size, at least 90% of the beads by population below 6.0 .mu.m, as defined and a solvent for the binder. The crosslinked beads can be present in positive-working systems. Preferred beads are trimethylolpropane triacrylate. The coating composition can be dried quickly into the form of a film which is useful as a dry film photoresist.Type: GrantFiled: May 18, 1984Date of Patent: November 5, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Vincent J. Webers
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Patent number: 4527890Abstract: Apparatus for registering and imagewise exposing to actinic radiation a sequence of similar sheet substrates employing liquid applicator means to allow a photomask to contact a photosensitive layer on the substrate through a liquid.Type: GrantFiled: August 15, 1983Date of Patent: July 9, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventors: Robert B. Heiart, Abraham B. Cohen
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Patent number: 4522903Abstract: Method for repetitive registering and imagewise exposing to actinic radiation a sheet substrate containing a photosensitive layer with use of a sequence of related photomasks. A liquid layer separates the photosensitive layer and each photomask during the exposure step.Type: GrantFiled: June 11, 1982Date of Patent: June 11, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventors: Robert B. Heiart, Abraham B. Cohen
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Patent number: 4518667Abstract: Method and apparatus for registering and imagewise exposing to actinic radiation a sequence of similar sheet substrates. A liquid layer separates the photosensitive layer and each photomask during the exposure step.Type: GrantFiled: June 11, 1982Date of Patent: May 21, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventors: Robert B. Heiart, Abraham B. Cohen
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Patent number: 4508802Abstract: Method for registering and imagewise exposing to actinic radiation a sequence of sheet substrates which are registerable to one another to produce a composite image.A liquid layer separates the photomask and photosensitive layer of the substrate during the exposure.Type: GrantFiled: June 11, 1982Date of Patent: April 2, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventors: Robert B. Heiart, Abraham B. Cohen
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Patent number: 4414278Abstract: Discrete, substantially nonswellable crosslinked polymeric beads, 0.7 to 20 .mu.m average diameter wherein at least 90% of the beads by population are below 20 .mu.m, which are nonagglomerating in any solvent or solvents including solvents for the liquid monomer or monomers used in preparation thereof. The polymeric beads are homopolymers of tri- and tetraacrylate and tri- and tetramethacrylate monomers, copolymers thereof, copolymers of one of said acrylate or methacrylate monomers with up to 50% of a monomer having a single terminal ethylenic group or with up to 75% of a monomer having two terminal ethylenic groups or three terminal ethylenic groups different from said triacrylate or trimethacrylate monomers defined above.Type: GrantFiled: April 22, 1982Date of Patent: November 8, 1983Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Christina N. Lazaridis
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Patent number: 4405394Abstract: In a process for laminating a photosensitive layer to a aluminum or copper substrate surface by means of nip rolls, the improvement comprising the sequential steps of:(a) rendering the substrate surface clean, as defined by the uniform water film test;(b) within about 1 minute after rendering the substrate clean and immediately prior to lamination, applying a thin layer of liquid to form an interface between the substrate surface and the photosensitive layer;(c) displacing the thin layer of liquid from the interface by absorption into the photosensitive layer during lamination, and(d) within 30 seconds after lamination, removing the support for the photosensitive layer without delamination of the photosensitive layer from the substrate by bending the support back along a longitudinal axis of the photosensitive layer.Type: GrantFiled: January 22, 1982Date of Patent: September 20, 1983Assignee: E. I. Du Pont de Nemours and CompanyInventor: Abraham B. Cohen
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Patent number: 4357413Abstract: A dry-developing dry film resist is provided comprising a photopolymerizable layer preferably sandwiched between a support sheet and a cover sheet, the layer comprising polymerizable monomer in excess of the absorptive capacity of the layer, photopolymerization initiator, and binder component of a plurality of polymers, at least one of these polymers being incompatible so as to be present as a dispersion in the layer to reduce the cohesive strength of the layer. The layer is developed by peeling away the support sheet, the unexposed area of the layer adhering to the support sheet and the exposed area adhering to the substrate to which it was laminated to form a resist image against such treatments as etching, plating and soldering, especially to make a printed circuit.Type: GrantFiled: March 27, 1981Date of Patent: November 2, 1982Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Joseph E. Gervay
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Patent number: 4356251Abstract: An improved photosensitive element for producing reverse solvent developed images comprising a cover sheet, a photoadherent layer, and a solvent-soluble, non-tonable contiguous layer for photomechanical applications.Type: GrantFiled: August 4, 1980Date of Patent: October 26, 1982Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Roxy Fan
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Patent number: 4355055Abstract: Preparation of an electrically conductive pattern by adhering a prolonged tack toner which is activated by heating to the toner-receptive image areas of an inert substrate, the temperature is reduced and to the activated toner is applied a prolonged tack toner having conductive metal particles and glass frit as components; optionally the steps of heating, temperature reduction and toner application are repeated at least one time, and then the toned image is burned and fired. An electrically conductive pattern is obtained which is useful, for example, as an electric circuit. The process is also useful in the application of resistor and dielectric materials.Type: GrantFiled: July 30, 1981Date of Patent: October 19, 1982Assignee: E. I. Du Pont de Nemours and CompanyInventors: Grant A. Beske, Abraham B. Cohen, Roger O. Uhler
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Patent number: 4339525Abstract: Photopolymerizable elements are described comprising a sheet support, a photopolymerizable layer having a thickness of, at most, 0.0006 inch (0.015 mm.) and an optical density of at least 3.0 in the actinic region. Resist images made from these elements may be etched by a process of chemically undercutting the image areas and then spraying or rubbing them. At least two dot-etched photopolymerizable elements, each exposed through a different color separation negative and colored accordingly, are placed in registration to form a color proofing system.Type: GrantFiled: December 31, 1979Date of Patent: July 13, 1982Assignee: E. I. Du Pont de Nemours and CompanyInventors: Martin D. Bratt, Abraham B. Cohen
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Patent number: 4331712Abstract: A process is described to uniformly apply finely divided material to tacky surfaces. The process comprises the physical treatment of particulate material to reduce particle aggregates to smaller particles and depositing the particles on the tacky surface with substantially no shearing force. The particle covered surface is then worked or rubbed with a shearing force to redistribute and embed the particles into the tacky surface. By this process, surfaces which are uniformly tacky or which contain tacky image areas can be uniformly and consistently toned without the production of defects like streaks or mottle.Type: GrantFiled: November 18, 1977Date of Patent: May 25, 1982Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abraham B. Cohen, Michael J. Krawacki