Abstract:
A ceramic filled fluoropolymer-based electrical substrate material well suited for forming rigid printed wiring board substrate materials and integrated circuit chip carriers is presented which exhibits improved electrical performance over other printed wiring board materials and circuit chip carriers. Also, the low coefficients of thermal expansion and compliant nature of this electrical substrate material results in improved surface mount reliability and plated through-hole reliability. The electrical substrate material preferably comprises polytetrafluoroethylene filled with silica along with a small amount of microfiberglass. In an important feature of this invention, the ceramic filler (silica) is coated with a silane coating material which renders the surface of the ceramic hydrophobic and provides improved tensile strength, peel strength and dimensional stability.
Abstract:
A ceramic filled fluoropolymer-based electrical substrate material well suited for forming rigid printed wiring board substrate materials and integrated circuit chip carriers is presented which exhibits improved electrical performance over other printed wiring board materials and circuit chip carriers. Also, the low coefficients of thermal expansion and compliant nature of this electrical substrate material results in improved surface mount reliability and plated through-hole reliability. The electrical substrate material preferably comprises polytetrafluoroethylene filled with silica along with a small amount of microfiberglass. In an important feature of this invention, the ceramic filler (silica) is coated with a silane coating material which renders the surface of the ceramic hydrophobic and provides improved tensile strength, peel strength and dimensional stability.
Abstract:
A parallel plate waveguide microwave antenna is presented in which transmission or reception of microwave energy is effected by radiating waveguide slots or apertures in a metallized glass plate or plate of other rigid dielectric material. The metallized glass plate cooperates with another metallized glass plate or other rigid dielectric material or a metal plate to define a parallel plate waveguide with air or an inert gas or vacuum as the dielectric between the plates. When used as a transmitter antenna, a central electrode propagates waves in the dielectric medium in expanding circles; and the slots or apertures in the metal layer act as scattering sites to couple the waves to free space. When used as a receiver antenna, the reverse will occur.
Abstract:
A microstrip antenna is presented in which the circuit pattern is on the inner side of a glass plate and is spaced from the ground plane by an air dielectric. The outer side of the glass plate serves as a protective cover for the circuit pattern and the ground plane.
Abstract:
Microwave circuit boards and methods of making microwave circuit boards, the circuit boards having relatively high dielectric constants, excellent moisture resistance, and reduced tendency to incur changes in dimensions after processing. The method comprises blending in a polymer dispersion, a particulate filler material having a high dielectric constant and microfibrous material to form a slurry of polymer, filler, and fiber. A flocculant is added to the slurry to agglomerate the polymer particles, the filler particles, and the microfibers to produce a dough-like material. The dough-like material is eventually formed into a sheet, and is thereafter dried. A conductive foil such as copper is then applied to both sides of the sheet to provide a microwave circuit board.