Patents Examined by Francis J. Husar
  • Printed wiring board comprising a conductive pattern retreating at least partly in a through-hole
    Patent number: 4179800
    Abstract: In a printed wiring board having an outwardly flaring through-hole, a conductive pattern is formed on the inwardly directed surface of the hole so as to reach a principal surface of the board only at that circumferential portion of the hole where the pattern is continuous to a pattern portion, if any, formed on the principal surface. The pattern is formed in the through-hole by positive use of that portion of a photoresist film formed on the principal surface to cover the hole which partly protrudes into the hole.
    Type: Grant
    Filed: May 15, 1978
    Date of Patent: December 25, 1979
    Assignee: Nippon Electric Company, Ltd.
    Inventors: Toshio Takaba, Toshimasa Kobayashi