Abstract:
Bistriazene compounds such as ##STR1## are useful for crosslinking polymers such as poly(imides), poly(aryl ether ketones), poly(aryl ether sulfones), poly(quinolines), poly(quinoxalines), and nonaromatic fluoropolymers having aliphatic C--H groups. Polymers crosslinked with these bistriazene compounds are useful as interlayer insulators in multilayer integrated circuit articles.
Abstract:
Functional films comprising a thermoplastic resin having formed thereon a coating layer and a process for their production are disclosed. The films have improved properties including improved heat resistance, are inexpensive, and are for general-purpose. They are produced by baking a thin film of a phenol resin, an epoxy resin, a silicone resin, etc., onto a thermoplastic resin substrate and can be utilized for flexible printed circuit base, insulating tapes, etc.
Abstract:
Methods of fabricating multilayer circuits are presented. In accordance with the present invention, a plurality of circuit layers comprised of a dielectric substrate having a circuit formed thereon are stacked, one on top of the other. The dielectric substrate is composed of a polymeric material capable of undergoing fusion bonding such as a fluoropolymeric based substrate. Fusible conductive bonding material (e.g. solder) is applied on selected exposed circuit traces (prior to the stacking step) whereupon the entire stack-up is subjected to lamination under heat and pressure to simultaneously fuse all of the substrate and conductive layers together to form an integral multilayer circuit having solid conductive interconnects.
Abstract:
A composite material is presented comprised of a ceramic filled fluoropolymer wherein the ceramic is coated with a zirconate coupling agent and/or a titanate coupling agent.
Abstract:
A method of ablating fluoropolymer composite materials is presented wherein it has been found that small holes (less than 100 .mu.m) can be formed in fluoropolymer composite laminate materials using UV lasers. The resulting holes can be used to produce vias and plated through-holes having smooth side walls with little or no debris or residue remaining in the holes and minimal damage to the polymer. Thus, the vias and plated through-holes can be plated without further cleaning processes. In addition, the holes are formed at a relatively fast rate.
Abstract:
A process is provided for making a laminated board useful in printed circuitry. The process involves laminating a metal layer to at least one side of a sheet of porous, expanded polytetrafluoroethylene using an adhesive followed by compressing the polytetrafluoroethylene sheet to increase its density. The metal layer may be a metal foil or it may comprise electrical circuitry. Also provided are printed circuit boards produced by the aforesaid process.
Abstract:
A fluoropolymeric circuit laminate consisting of one or more layers of fluoropolymer impregnated woven glass cloth sandwiched between one or more layers of "random" microfiberglass reinforced fluoropolymer is presented. This composite of fluoropolymer, woven glass fabric and random glass microfibers may be clad on one or both outer surfaces with a suitable conductive material such as copper or certain known resistive foils. The fluoropolymer impregnated woven glass layer or layers will be nested between microfiberglass reinforced fluoropolymer layers to provide the outer surfaces of the circuit with smooth surfaces for fine line circuitry. The circuit laminate of the present invention exhibits good dimensional stability, smooth surfaces for fine line circuitry, good electrical properties, and strong foil and interlaminar adhesion properties.
Abstract:
A multilayer circuit board consisting of multiple circuit layers supported on sheets of PTFE or PTFE containing a fibrous stiffening agent, said circuit-bearing sheets being joined in fixed relative positions by means of separating layers of a adhesive unsintered tetrafluoroethylene resin.
Abstract:
A printed circuit board is provided wherein a composite metal layer is affixed to at least one surface of a flexible dielectric substrate, the composite metal layer comprising an inner aluminum layer and an outer copper layer. Owing to the relatively high elongation of the aluminum layer, when the printed circuit board is flexed the circuit thereon does not crack.