Patents by Inventor Rolf Rolff

Rolf Rolff 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).

  • Patent number: 4619740
    Abstract: A method for measuring the density of a current during an electroplating process in an electroplating bath, wherein a voltage is measured by a voltmeter, positioned outside the bath, immediately between the outer surface of the item to be electroplated and the outer surface of an isolated metallic island.
    Type: Grant
    Filed: March 18, 1985
    Date of Patent: October 28, 1986
    Assignee: Schering Aktiengesellschaft
    Inventors: Detlev Nitsche, Rolf Rolff
  • Patent number: 4461690
    Abstract: A reference branch circuit includes a voltage divider. Each of at least one regulated branch circuits includes the collector-emitter circuit of a regulating transistor and a measuring resistance. Each regulated branch circuit is associated with a comparator, which compares voltage across the measuring resistance of the corresponding regulated branch circuit to a reference voltage appearing at a reference tap of the voltage divider in the reference branch circuit. Current passing through each regulated branch circuit is regulated to be equal to the current flowing through the reference branch circuit.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: July 24, 1984
    Assignee: Schering AG
    Inventors: Rolf Rolff, Detlev Nitsche
  • Patent number: 4253875
    Abstract: A catalytic lacquer for the production of printed circuit boards using basic materials and metal deposition methods. The lacquer has the following composition: a binding agent based on synthetic or natural materials; water; a metal salt; a complex former; and a reducing agent. The binding agent may be a water soluble or dispersable compound. The metal salt may be a water soluble palladium, copper, silver, gold or nickel salt, preferably the sulphate. The complex former may be in the form of a compound forming stable complexes with metal ions. The reducing agent may be in the form of formaldehyde, hydrazine or its derivatives, boron compounds, sorbitols, phosphites, or hydrophosphites. The lacquer may also include an organic solvent or solvent mixture, preferably methylene chloride. A filler and stabilizer may also be included in the composition of the lacquer.
    Type: Grant
    Filed: November 3, 1978
    Date of Patent: March 3, 1981
    Assignee: Schering Aktiengesellschaft
    Inventors: Kurt Heymann, Rolf Rolff