Patents by Inventor Walter J. Symes, Jr.

Walter J. Symes, Jr. 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: 5599757
    Abstract: A low temperature fired NPO type ceramic dielectric composition is employed for making high frequency multi-layer capacitors having dielectric constants between 25 and 40 at room temperature, and which do not vary from this base line value by more than .+-.30 parts per million (PPM)/.degree.C. over a temperature range of -55.degree. C. to +125.degree. C. with the value at +25.degree. C. being the reference point. The dielectric composition is made from a base dielectric ceramic formulation and a low melting point glass formulation, each derived from metal oxides or precursors thereof. Manganese dioxide or a precursor thereof may be added in the amount of from about 0.012 to 0.060 weight percent as the dioxide based on the combined weight of the ceramic formulation and the glass formulation. The mixtures, when made into multi-layer ceramic capacitors (MLCC), are fired at or below 1120.degree. C.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: February 4, 1997
    Assignee: Ferro Corporation
    Inventors: James M. Wilson, Walter J. Symes, Jr.
  • Patent number: 5571767
    Abstract: Multi-layer ceramic capacitors are made from novel low temperature fired ceramic dielectric compositions which may have dielectric constants of over 3200 at room temperature, and which do not vary in value by more than 15 percent over a temperature range of -55.degree. C. to +125.degree. C., with the value at +25.degree. C. being the reference point. The compositions comprise a base ceramic formulation or host material, a ceramic sintering aid, and a low melting point glass formulation, each derived from metal oxides or precursors thereof. The host material is made from 97.89 to 98.19 weight percent barium titanate and from about 1.81 to 2.11 weight percent neodymium oxide, the sintering aid from Bi.sub.2 O.sub.3 .multidot.2TiO.sub.2, and the the glass formulation from 86.0 wt. % PbO, 9.0 wt. % B.sub.2 O.sub.3, 1.58 wt. % SiO.sub.2, 0.13 wt. % TiO.sub.2 and 3.29 wt. % Al.sub.2 O.sub.3. Manganese dioxide or a precursor is added in an amount of about 0.205 wt.
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: November 5, 1996
    Assignee: Ferro Corporation
    Inventors: James M. Wilson, Walter J. Symes, Jr.