Patents by Inventor Petrus Johannes Janssen

Petrus Johannes Janssen 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).

  • Method of manufacturing printed circuit boards
    Patent number: 4085285
    Abstract: Manufacture of photosensitive material by a dispersion of particles of semiconducting metal oxide having a charge sign opposite to that of the substrate in the dispersion agent, which dispersion is provided on the substrate surface and adhered thereto. In a similar manner walls of a hole for electrical through-connections are made photosensitive as a pretreatment for metal-plating.
    Type: Grant
    Filed: August 6, 1976
    Date of Patent: April 18, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Gerardus Johannes Meinardus Lippits, Petrus Johannes Janssen, Henricus Antonius Debruijn, Johannes VAN Ruler