Laminar stackable circuit board structure with capacitor

Abstract

Method and apparatus for fabricating fine pitch pattern multilayer printed circuit boards involving laminar stackable board layers providing power distribution, signal distribution and capacitive decoupling. In one respect, the invention relates to the fabrication of board layers by beginning with a metallic core, patterning the core, selectively enclosing the core in a dielectric, selectively depositing metal to form vias, plugs and signal lines, and forming dendrites with joining metallurgy on the vias and plugs to provide stackable connection from above or below the plane of the board layer. In another aspect, the invention is directed to the use of a sol-gel process to form a thin high dielectric constant crystalline film onto a metallic sheet followed with a deposition of a metallic layer onto the high dielectric constant film. The film serves as the dielectric of a capacitor layer which is thereafter in succession patterned, covered by a dielectric, and has selectively deposited a metallic layer for interconnecting the capacitor and forming vias. The ends of the vias are thereafter subject to dendritic growth and joining metallurgy to provide stackable interconnection capability. A multilayer composite laminar stackable circuit board structure is created using, as appropriate, layers having metallic cores and layers having capacitively configured cores. The multilayer laminar stackable circuit board provides direct vertical connection between surface mounted electronic components and the power, signal and capacitive decoupling layers of the composite board through the dendrites and joining metallurgy of the via and plug formations.