Patents Examined by George E. Forson
  • Patent number: 5544773
    Abstract: Provided is a method for making a multilayer printed circuit board having blind holes which comprises heat laminating a copper foil and an inner layer panel previously provided with circuit patterns on one or both sides thereof by processing a copper-clad laminate, a resin layer soluble in an aqueous alkali solution and having a flowability upon heating being present between said copper foil and said inner layer panel, forming via holes in the surface copper foil by etching and then dissolving the resin layer under said via holes with an aqueous alkali solution and removing the resin layer, thereby to form blind holes in which the copper foil on the inner layer panel is exposed. Further provided is a copper foil used for making multilayer printed circuit boards, which is provided with a resin layer soluble in an aqueous alkali solution and having flowability upon heating on its roughened surface.
    Type: Grant
    Filed: June 2, 1994
    Date of Patent: August 13, 1996
    Inventors: Youichi Haruta, Tomio Kambayashi, Hitoshi Kato, Hiromu Taguchi