Abstract: An improved stereolithographic apparatus and method is described. In one embodiment, the improvement includes immersing at least a portion of a part in a volume of a liquid solvent in a vapor degreaser while subjecting the portion to ultrasonic agitation to substantially remove excess resin. Several examples of solvents are provided, including ethanol, and Freon TMS. In a second embodiment, the improvement includes building the part on a layer of liquid resin supported by a volume of a dense, immiscible, and UV transparent intermediate liquid, and integratably immersing at least a portion of the built part in the intermediate liquid, and then either subjecting the immersed portion to ultrasonic agitation to substantially remove excess resin, or subjecting the immersed portion to UV light. Several examples of intermediate liquids are provided, including perfluorinated fluids, such as Fluorinert FC-40, and water-based salt solutions, such as solutions of magnesium sulfate or sodium chloride in water.

Abstract: Methods for forming small diameter holes in polyimide/Kelvar.RTM. substrates utilize hot concentrated sulfuric acid and then honing, as necessary, with liquid abradant slurries to smooth uneven edges of the openings.

Abstract: A process for forming on the surface of a substrate a layer of a siloxane polymer by exposing the substrate to a first vapor phase monomer precursor having the formula SiR.sub.x H.sub.4-x where x is 1 to 4 and R is alkyl or phenyl, and a second vapor phase oxygen-containing precursor in the presence of radiation of a predetermined wavelength to bring about the reaction to form the siloxane polymer which deposits on the surface of substrate. The monomer precursor may comprise a mixture, such as SiRH.sub.3 and SiR.sub.2 H.sub.2 with each other or with SiR.sub.3 H. By varying the composition of such mixtures, the composition of the siloxane polymer may be chosen to provide predetermined properties, and, further, may be varied throughout the thickness of the deposited layer.

Abstract: Methods for forming holes of predetermined size in polyimide substrates having metallic layers adhesively attached thereto include selectively removing areas of desired size and shape from the metallic layer; contacting the exposed adhesive layer with a selective etchant therefor that does not affect the polyimide substrate or undercut the adhesive near the opening formed; and selectively etching the polyimide substrate exposed in the openings by removal of the adhesive layer overlying the polyimides. These methods permit rapid, efficient formation of holes having a diameter as small as one mil (0.00254 cm).

Abstract: A low-temperature process for forming a thin film of an aromatic polymer on the surface of a substrate by exposing the substrate to a monomer precursor containing arylene groups in the presence of radiation of a selected wavelength. Upon radiation inducement, the monomer units interact to form a polymer comprising directly bonded repeating arylene groups, and the polymer deposits as a layer on the substrate. Optionally, the polymer layer may be simultaneously or subsequently doped to provide a conductive polymer layer. Specifically disclosed polymers are polyparaphenylene and its antimony pentafluoride-doped derivative. The former is useful as a dielectric insulator or passivation material in semiconductor devices and circuits, while the latter is useful in batteries and solar cells, or electromagnetic shielding.

Abstract: A low temperature photochemical vapor deposition process for the deposition of a layer of a chosen polymer on the surface of a substrate. The polymer comprises repeating hydrocarbon units linked through oxygen, nitrogen, or sulfur atoms and is formed by reacting a vapor phase monomer precursor containing the hydrocarbon units and a vapor phase precursor containing the oxygen, nitrogen, or sulfur under radiation inducement. The low temperature of the process avoids thermal damage to the substrate. Specifically disclosed polymers are polyphenylether and polyxyleneamine, which are useful, respectively, as insulator or passivation layers in semiconductor devices and circuits, and as adhesives.