Abstract: The invention concerns a method for making an multilevel interconnection circuitry comprising conductor tracks and micro-vias. The method for producing at least one of the levels comprises the following steps: a) on a substrate including at its surface metallizable and/or potentially metallizable parts (102), forming a first insulating photosensitive resin layer (103) comprising a compound capable of inducing subsequent metallization; b) exposing and revealing the first layer (103) so as to selectively uncover the metallizable and/or potentially metallizable parts (102) of the substrate; c) forming, by metallization, metal conductor tracks (111) and micro-vias (110) at the surface of the first insulating photosensitive resin layer (113) and of the parts uncovered during step b), by providing a second photosensitive resin layer (105) forming a selective protection, the second photosensitive resin layer (105) being eliminated.

Abstract: The invention concerns a method for making a circuitry comprising conductive tracks, chips and micro-vias, at the top surface of a dielectric (303) consisting of a polymer matrix, a compound capable of inducing subsequent metallization and, if required one or several non-conductive and inert fillers, said dielectric (303) covering a level of circuitry (302) or metallized layer, which comprises steps which consist in: a) perforating right through said dielectric (303) without perforating the subjacent metallized layer or the subjacent level of circuitry (302), so as to form one or several micro-vias (304) at desired sites; b) forming, by metallization, metal tracks (312), chips (313) and micro-vias (311) at the surface of the dielectric (314) and of the micro-vias (304), while providing selective protection by depositing a protective layer.

Abstract: A composite material and a method for making same are disclosed. A composite article including an electrically and/or thermally insulating substrate and protective layers on each side thereof is particularly disclosed. Said material includes protective layers consisting of fibers of a heat-stable material flocked onto the insulating substrate, and heat-stable coating resin. The resulting protective layer has improved protective properties, particularly moisture-proofness. The composite material may also be used as a metal layer carrier for forming flexible printed electrical circuits.

Abstract: The present invention relates to a reactivable paper and to a process for obtaining it.The paper consists of fibres with a heat resistance .gtoreq.180.degree. C., bonded together by means of a fibrous binder composed of polyamide or aromatic polyester pulp and of a chemical binder consisting of a polyether-imide of an aromatic polyester or of a resin of polyimide type, with a particle size smaller than 100 .mu.m, a softening point of between 50.degree. and 200.degree. C., and a degree of crosslinking of between 0.025 and 0.25. The weight proportion of fibres in the finished paper is generally preferably between 45 and 85%, that of the fibrous binder between 5 and 20%, that of the chemical binder between 10 and 50%.The papers are obtained by a wet route and find wide applications as a function of the degree of conversion of the resin, for example as a dielectric.

Abstract: A process for coating a plastics article with a thin layer of noble metal, wherein said plastics article contains a finely particulate, homogenized filler selected from the group consisting of MnO, NiO, Cu.sub.2 O, SnO and Bi.sub.2 O.sub.3, and said plastics article is coated with an acid aqueous solution of a noble metal salt.

Abstract: Substrate composites, well adopted for the production of metallized printed circuits and facilely prepared by, e.g., papermaking procedures, include a central core layer comprising fibrous cellulosic material or flaked mica within a matrix of a thermosetting resin binder, said central core element having coextensively laminated to at least one of the face surfaces thereof, a lamina of a thermosetting resin comprising non-conductive metal oxide filler material distributed therethrough, and said metal oxide being borohydride reduceable and reactive to form unstable metal hydride intermediates.

Abstract: Thick-layer hybrid electronic printed circuits are formed by printing predetermined circuit pattern onto an insulating substrate by deposition of predetermined ink pattern thereupon, advantageously by silk-screening or masking, and thence baking said ink circuit pattern, and repeating the deposition/baking steps as required, the subject forming process featuring use of an insulating ink comprising a non-conductive metallic oxide extender, desirably cuprous oxide, which ink is thus either potentially conductive or potentially resistive, and the development of such conductivity or resistivity, after baking, by treating the ink pattern with a reducing agent, desirably a borohydride, as to readily and quantitatively convert said metal oxide into a conducting metal.

Abstract: Substrate composites, well adopted for the production of metallized printed circuits and facilely prepared by, e.g., papermaking procedures, include a central core layer comprising fibrous cellulosic material or flaked mica within a matrix of a thermosetting resin binder, said central core element having coextensively laminated to at least one of the face surfaces thereof, a lamina of a thermosetting resin comprising non-conductive metal oxide filler material distributed therethrough, and said metal oxide being borohydride reduceable and reactive to form unstable metal hydride intermediates.

Abstract: Plastic substrata are metallized, preferably by direct electrolytic metallization, by (i) providing a plastic shaped article comprising intimate admixture of a polymeric resin and a plurality of small metallic filler particles of a non-conductive oxide of a non-noble metal uniformly dispersed therethrough, at least one of the face surfaces of said shaped article having exposed thereon such high density of said metallic filler particles as to provide in step (ii) metallization growth nuclei adapted for direct electrolytic metallization; (ii) next subjecting said at least one face surface of said plastic shaped article to the action of a reducing agent to essentially quantitatively convert the non-conductive metal oxide filler particles to conductive free metal, metallization growth nuclei; and (iii) thence electrochemically and/or electrolytically metallizing the at least one reduced face surface of said plastic shaped article with a free metal deposit.

Abstract: Electrically insulating polyimide/aromatic polyamide film substrates are conductively metallized, e.g.

Abstract: Electrically insulating polymeric film substrates are conductively metallized, e.g.

Abstract: A metallized, laminated substrate well adapted for the production of printed circuits is comprised of:(A) an electrically insulating support element which comprises (a) a central core member comprising a major proportion by weight of a cellulosic or mica filler and a minor proportion by weight of a thermosetting resin, and (b) and (b') a pair of skin laminae coextensively secured to each face surface, respectively, of said central core (a), each of said skin laminae comprising a fibrous glass, asbestos or heat-stable synthetic polymer reinforcing filler, and a thermosetting resin impregnant, which thermosetting resin may either be the same as or different from the thermosetting resin comprising said central core member (a); and(B) an electrically conducting metal foil (c) coextensively adhered to the exposed face surface of one or the other of said skin laminae (b) or (b').

Abstract: Essentially isotropic metallizable polymeric substrates having very low coefficients of thermal expansion are well adopted for printed circuits, are facilely prepared by papermaking technique and hot pressing, and are comprised of a fibrous polymer matrix, advantageously an aramide non-woven batt, bonded together with a cured imido prepolymer, and include particulate filler material, advantageously electrically insulating metal oxide particles, distributed therethrough.

Abstract: Thick-layer hybrid electronic printed circuits are formed by printing predetermined circuit pattern onto an insulating substrate by deposition of predetermined ink pattern thereupon, advantageously by silk-screening or masking, and then baking said ink circuit pattern, and repeating the deposition/baking steps as required, the subject forming process featuring use of an insulating ink comprising a non-conductive metallic oxide extender, desirably cuprous oxide, which ink is thus either potentially conductive or potentially resistive, and the development of such conductivity or resistivity, after baking, by treating the ink pattern with a reducing agent, desirably a borohydride, as to readily and quantitatively convert said metal oxide into a conducting metal.

Abstract: A metallized, laminated substrate well adapted for the production of printed circuits is comprised of:(A) an electrically insulating support element which comprises (a) a central core member comprising a major proportion by weight of a cellulosic or mica filler and a minor proportion by weight of a thermosetting resin, and (b) and (b') a pair of skin laminae coextensively secured to each face surface, respectively, of said central core (a) each of said skin laminae comprising a fibrous glass, asbestos or heat-stable synthetic polymer reinforcing filler, and a thermosetting resin impregnant, which thermosetting resin may either be the same as or different from the thermosetting resin comprising said central core member (a); and(B) an electrically conducting metal foil (c) coextensively adhered to the exposed face surface of one or the other of said skin laminae (b) or (b').

Abstract: Novel thermosetting compositions, including a polyimide/N-vinylpyrrolidone prepolymer, optionally comprising an unsaturated polyester, and an epoxy resin, are well adapted for the molding of a variety of useful shaped articles.

Abstract: Novel thermosetting compositions, including a polyimide/N-vinylpyrrolidone prepolymer, optionally comprising an unsaturated polyester, and an epoxy resin, are well adapted for the molding of a variety of useful shaped articles.

Abstract: A modular, constructional heating unit, useful, e.g., for the fabrication of interior partitions, is comprised of a panel member provided with at least one elongate rectilinear cavity, the longitudinal axis of such cavity being parallel to a face surface of the panel, said cavity being exteriorly communicating at one or both of its ends, and said cavity containing an electrical heating element.

Abstract: A heating element is comprised of [A] a shaped, electrically insulating substrate, said substrate including a reinforced polyimide composite, [B] a continuous, electric resistor element in entwining relationship with, and at least partially inlain within said composite [A], said electric resistor element being coated with a thermostable electrically insulating coating, and [C] means for coupling said electric resistor element [B] with an electric power source. Techniques for the fabrication of such heating elements are also disclosed.

Abstract: Novel copolymers are comprised of oligo-imide/hydroxylated organosilicon comonomers, or of oligo-imide/polyamine/hydroxylated organosilicon comonomers. Such copolymers are useful in the production of coatings and a variety of shaped articles, e.g., molded and/or foamed shaped articles, laminates and the like.