This invention relates generally to a flexible high dielectric constant sheet material for use in electronic circuitry and electronic components. More particularly, this invention relates to a high dielectric constant sheet material which is flexible, drillable, platable, and is which well suited for a variety of uses including high current laminated bus bars, multilayer printed circuit boards, flexible circuits and decoupling capacitors.
It will be appreciated that there is an ever increasing need for a reliable, flexible high dielectric material which may be used for a variety of applications in electronic circuitry design and manufacture. Presently, flexible high dielectric materials of this type are manufactured by mixing small particles (for example 1-3 microns) of a high dielectric constant material into a flexible polymeric matrix. Suprisingly, the resultant effective dielectric constant of the dielectric impregnated polymer is relatively low. For example, the dielectric constant of a Z5U BaTiO.sub.3 is in the range of 10,000 to 12,000. However, when such Barium Titanate is mixed with a flexible polymer such as polyimide, polyester, polyetherimide and like materials, the effective dielectric constant realizable is only on the order of 20 to 40 (depending on the loading ratio of the dielectric in the polymer).