Patents by Inventor David W. Grenda

David W. Grenda 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: 4289597
    Abstract: A process is provided for regenerating a spent electroless copper plating bath which contains alkali metal salts resulting from the reduction of a water soluble copper salt under copper plating and reducing conditions. The regeneration is effected by means of the electrodialytic transfer of at least a portion of the anions in the spent plating bath through an anionic permselective membrane into the anode compartment of an electrodialytic cell. In the preferred embodiment, hydroxyl ions from the cathode compartment of the electrodialytic cell are concurrently transferred through a second anionic permselective membrane to replace the transferred anions, the replacement taking place in a compartment of the electrodialytic cell located between the two anionic permselective membranes.
    Type: Grant
    Filed: February 19, 1980
    Date of Patent: September 15, 1981
    Assignee: Electrochem International, Inc.
    Inventor: David W. Grenda
  • Patent number: 4252618
    Abstract: An improved electroplating process and electroplating bath therefor is disclosed which is adapted to electrodeposit a tin-bismuth alloy. The electroplating bath contains tin ions, an alkali metal hydroxide, and bismuth citrate. Bismuth citrate exhibits relatively high solubility in hot alkaline alkali metal stannate electroplating baths when compared to conventional alkali metal bismuthates or other bismuth compounds which in general have poor solubility in hot alkali metal stannate electroplating baths. An improved process is provided for electrodepositing a tin-bismuth alloy on panels as adherent and uniform plates without signs of staining or tin-bismuth nodules. An additional and important feature of this invention is the advantageous blending of the bismuth citrate with the alkalic metal stannate in the dry solid state, if and when desired.
    Type: Grant
    Filed: February 11, 1980
    Date of Patent: February 24, 1981
    Assignee: Pitt Metals & Chemicals, Inc.
    Inventor: David W. Grenda