Abstract: A printed circuit board is formed from a metal-clad substrate by applying a solvent-free, non-dryable ink in a predetermined pattern on the substrate, dusting powdered resin over the surface, removing any resin powder not retained by the ink from the surface, heating the substrate having the ink powder thereon to a temperature so as to fuse the powdered resin to form a strippable resist, etching the uncoated portion of the metal laminate and stripping the resist subsequent to etching.

Abstract: An apparatus for substantially eliminating excessive edge growth in liquid phase epitaxy utilizing a substrate carrier 11 and a source material carrier 13 slidable over the substrate carrier 11 including a well 24 around a recess 14 in the substrate carrier 11 wherein the substrate 16 is held. The well 24 contains a material therein which reduces the heat loss from the edges of the substrate 16 held in the recess 14 thereby reducing excessive epitaxial growth around the edges of the substrate 16.

Abstract: A method of electrolessly plating a substrate having a rubber-modified epoxy surface includes the steps of preheating the substrate and while still warm, sputter etching at least 50A. from its surface. The substrate is then vacuum metalized with an adhesion promoting metal film, coated with a catalytic layer and a metal is electrolessly deposited thereover.

Abstract: An electronic device such as an integrated circuit is encapsulated within a silicone resin formulation having a protonated heterocyclic compound contained therein. The compound complexes with free anionic contaminants to form a non-migratory, non-corrosive protonated heterocyclic compound-anion complex, thereby preventing anionic attack of metallic circuit elements.

Abstract: A method for preventing solder sticking on printed circuit substrates comprises mechanically roughening the surface of the substrate.

Abstract: A method of growing a semiconductor layer by liquid phase epitaxy utilizing a slide type apparatus comprising a substrate carrier having a recess for holding a substrate and a source material carrier slidably arranged over the surface of the substrate carrier and including a well around the recess, comprises the steps of filling said well with material selected from a thermally insulating material and a material which is molten at the temperature of crystal growth and then cycling the temperature of the apparatus in a manner so as to form an epitaxial layer on a substrate in the recess which layer is essentially free of excess edge growth.

Abstract: A printed circuit board is formed by forming a negative resist pattern over the surface of a substrate, etching the surface, sensitizing and catalyzing the surface, stripping the negative mask and catalytic layer thereover leaving a positive catalytic circuit pattern on the substrate and electrolessly plating copper over the catalytic image. A preferred variation of this method includes flash plating a thin porous electroless deposit over the catalyzed substrate prior to stripping the resist layer.

Abstract: A method of inhibiting solder sticking between circuit elements of a partially uncured rubber-modified epoxy printed circuit board comprises exposing the board containing the circuit pattern thereon to UV radiation prior to the application of solder thereto.

Abstract: A thermally conductive composition comprises an essentially homogeneous mixture of sand or sand-like particulate material with a binder, wherein the binder comprises an organic adhesive having an inorganic fine particle filler therein. The binder is present in at least an amount sufficient to begin to form a binder meniscus between adjacent sand particles, while the filler is present in the binder in an amount which significantly increases the effective thermal conductivity of the composition as compared to the same composition without filler.

Abstract: It has been discovered that by cleaning a substrate having a negative ink pattern of a desired circuit in a plasma comprising 60/40 oxygen/argon and then sputtering a thin (10-50 Angstroms) layer of catalytic copper thereover, the treated substrate when exposed to an electroless plating bath will selectively plate only in the areas where there is no ink.

Abstract: An apparatus useful for double crucible Czochralski crystal growth comprises an inner crucible fixed within an outer crucible wherein the inner crucible contains an extra volume or reservoir of semiconductor melt when flow of semiconductor melt from the outer crucible into the inner crucible through means interconnecting the crucibles ceases.

Abstract: A jacketed telephone cord is jacketed with a clear, flame retardant, stable composition which essentially does not exhibit vertical burn characteristics comprising an all phosphate plasticized PVC stabilized with the combination of a metallic stabilizer and a cycloaliphatic epoxy.

Abstract: A soldering flux comprises a mixture comprising a vehicle which is nonreactive with the portion of an electronic device to be contacted by the flux, an activator having at least one halogen atom and at least one destabilizing constituent and an acid solder surfactant selected from a polybasic carboxylic acid, a hydroxyl substituent thereof, a keto acid and a mixture of any of the foregoing surfactants.

Abstract: A process for softening high carbon, high chromium steel to render it machinable includes pre-heating, homogenizing, isothermally annealing and slow cooling the steel.

Abstract: A method of forming a colloidal wetting sensitizer is disclosed. The method comprises combining a stannous species and a cupric species in an aqueous medium maintained at a pH of between 0.4 and 1.5.

Abstract: A method of stabilizing a mixture of an organopolysiloxane and an organo-metallic curing catalyst against gelation comprises adding a sufficient amount of methanol to the catalyst to deactivate the catalyst prior to adding the catalyst to the polysiloxane.

Abstract: Tin and antimony impurities can be removed from copper scrap by melting the scrap in the presence of a flux comprising a mixture of calcium and solution oxides in a weight ratio of calcium oxide to sodium oxide of from 1:1 to 4:1.

Abstract: A method of fabricating a printed circuit board is disclosed. The method comprises forming a metal substrate having a through-hole pattern. The metal substrate is coated with a dielectric powder having a suitable flow length value to form a dielectric coat on the substrate having a sufficient through-hole edge coverage. The dielectric coated substrate is then treated with a second powder to form a satisfactory topcoat thereon. Electrical circuitry is then formed on the topcoat in conjunction with the through hole pattern.

Abstract: A method of depositing a uniform dielectric film on a silicon substrate comprising flowing a plasma comprising an RF-excited mixture of an inert gas such as argon and silane over the substrate to form a film of porous a-Si.sub.x H.sub.y over the surface of the substrate. The flow of plasma is then discontinued and a flow of a nitrogen or oxygen plasma is substituted therefor. The temperature of the substrate is increased to at least 360.degree. C. to diffuse-out hydrogen from the Si.sub.x H.sub.y film on the substrate, each departing hydrogen atom leaving a dangling Si bond behind which combines with the activated oxygen or nitrogen thereby to form the desired dielectric film of formula Si.sub.x N.sub.y or Si.sub.x O.sub.y.

Abstract: A mask for selectively transmitting therethrough a desired light radiant energy is disclosed. The mask comprises a stress-relieved, essentially dimensionally stable base, comprising a copolymer of tetrafluoroethylene and hexafluoropropylene, which is capable of transmitting therethrough the light radiant energy. A blocking film is deposited on at least a portion of the base for blocking the transmission of the light radiant energy through the portion of the base.