Abstract: A method for producing a soldered joint between the metal balls present in either a ball grid array or a chip-scale package, and the receiving pads for a circuit printed on a substrate or the receiving pads of an integrated circuit. Solder cream or an adhesive flux is deposited on the receiving pads, which then have metal balls are placed on them so as to form an assembly. The assembly is placed in an oven so as to heat the metal balls above their melting point. The balls are then cooled at a rate around 5° C./sec, so that the balls remain in their liquid state for a time period between 20 seconds to 65 seconds.

Abstract: The invention concerns a method for making a solder between metallic balls forming part, or designed to form part, of a BGA or CSP type housing or the like and mounting lands belonging to a printed circuit deposited on a support or to an integrated circuit enclosed in said housing. The method consists in: deposition of a solder cream or an adhesive flow on said mounting lands; bringing said balls on said mounting lands; and introducing the assembly in a soldering furnace by remelting so as to bring the metallic balls above their melting temperature. Said method is characterised in that it consists afterwards in forced cooling of the support and/or of the housing by imposing on the balls a cooling rate of 5° C./s at least.

Abstract: A method for delivering at least two working gases from a common air supply comprising the steps of depleting the air in O2 in order to obtain a first gas mixture having an O2 content less than or equal to t1; delivering at least a portion of this first gas mixture as a first working gas; depleting another portion of this first gas mixture in O2 in order to obtain the second gas mixture having an O2 content less than or equal to t2, wherein t1 is greater than t2; and delivering the second gas mixture as a second working gas.

Abstract: Process for producing an atmosphere for the manufacture of high performance composite parts, of the type wherein the atmosphere is used in an autoclave above a superposition of cutouts with fibrous structure impregnated with a thermosetting organic material disposed between a lower mold and an upper sealing covering member, the space between the covering member and the mold being under vacuum. The atmosphere is nitrogen gas prepared from raw nitrogen by separation from air through permeation or adsorption, incorporating a residual content of oxygen between 0.5% and 6%, with a low content of water vapor. Application for example to the manufacture of secondary and primary structures in aeronautical and space construction.

Abstract: The present invention relates to a multilayer protective coating for a substrate and a process for protecting a substrate by the deposition of a continuous, transparent, amorphous, inorganic coating essentially comprising silicon, carbon, nitrogen, oxygen and hydrogen by means of a plasma. The invention also concerns the application of the coatings according to the invention in the protection of substrates and in particular against electrostatic charges.

Abstract: Process for protecting a transparent optical substrate which is polymeric and has a vitreous transformation temperature and is selected from the group consisting of polycarbonate, polymethylmethacrylate, polystyrene acrylonitrile, crystalline polystyrene, polyimide, polyester, polyamide, polyvinyl chloride and glass, by deposition of an inorganic continous and transparent film consisting essentially of silicon, carbon, nitrogen, oxygen and hydrogen of the formula Si C.sub.x N.sub.y O.sub.z H.sub.t, in whichx is between 0 and 5y is between 0.3 and 0.8z is between 1.3 and 2.5t is between 0.5 and 1.2.A surface of the substrate is exposed to a plasma at a temperature below the temperature of vitreous transition of the substrate in the presence of precursors of Si, C, N, O and H is gaseous form, the precursor gas of the silicon being selected from the group consisting of SiH.sub.4, Si.sub.2 H.sub.6 and Si.sub.3 H.sub.

Abstract: A process for manufacturing calcium silicate and/or aluminate based products, such as Portland cement or aluminous cements. The raw material subjected to a first heating step in which it is heated in a preheater-decarbonator and/or a rotating kiln to a temperature less than that at which impurities, such as alkalines, chlorine and sulfur, are volatized. The heated raw material is then subjected to a second heating step in the presence of a reducing gas, preferably in a plasma furnace, the raw material being heated to a temperature higher than the temperature at which the impurities are volatilized, as for example above 1950.degree. C., and more than 80% of the material is in fusion, whereupon the material is cooled to produce the clinkers of improved quality and/or with lower energy consumption. An important feature of the invention is the utilization of the gases generated during the second heating step and during cooling to implement heating of the raw material.