Abstract: Composite structures are fabricated and cured without applying external heat from an autoclave or oven. This technique uses composite preforms to form high strength, three-dimensional co-bonded joints, and thermoplastic conformal mandrels such as rota-molded vacuum bags. The bags form internal tooling within the structure and provide molding with integral fittings that circulate heated air within the bags. The exteriors of the bags are simultaneously under vacuum and exert pressure on the composite elements of the structure that are being cured. This internally-applied heat initially causes to the bags to soften and fully conform to the internal shapes of the structure that are being co-bonded. The heat then transfers into the uncured materials, causing them to cure without unnecessarily heating the entire structure or any required tooling.

Abstract: Laminates have at least one resin-system layer, a low dielectric, low dissipation factor bond core having at least one surface that is treated for adhesion, such as by etching, plasma or Corona discharge or mechanical roughing to facilitate bonding to the at least one resin system layer and a conductive metal cladding on the at least one resin system layer. The bond core can be a fluoropolymer film or a fluoropolymer prepreg, having at least one etched or Corona discharge treated surface. Alternately, the bond core can be a polyetherimide film or a polyetherimide prepreg, having at least one etched or Corona discharge treated surface. The laminates are used, for example, high performance, low loss printed circuit boards. The laminates have the desired dielectric properties inherent to fluoropolymer materials and can be produced using conventional printed circuit board manufacturing processes, materials, and equipment. Methods of producing laminates are disclosed.