Abstract: In an electronic device assembly comprising at least one circuit element an encapsulant therefor, wherein the encapsulant comprises a silicone resin characterized in that subsequent to the curing of said encapsulant, the resin is coated with a fine inorganic powder such as fumed or fused silica which essentially eliminates static charge and tackiness of the surface.

Abstract: A method for preventing unwanted continued polymerization with aging of a polymer, e.g., a silicone gel, which was catalytically cured comprises treating the cured polymer with a catalytic deactivating agent or stabilization of cured resin.

Abstract: In a method of cleaning a circuit board having a silicone encapsulated hybrid integrated circuit thereon, subsequent to aqueous solder flux residue removal with an ionic detergent, the board is cleaned with a low molecular weight organic acid such as formic, acetic or oxalic acid.

Abstract: A method of extending the shelf-life of an uncured silicone resin formulation which includes a primary amine therein comprises adding an acid to the formulation in a molar quantity approximately equal to the number of moles of primary amine present in the formulation, said acid being volatile at or below the curing temperature of the resin formulation.

Abstract: An article of manufacture comprises an electronic device having a silicone resin encapsulant thereover, wherein the silicone resin is an oxime and water free formulation derived from curing a mixture consisting essentially of a heat curable silicone elastomer prepolymer and a dialkylaminoalkoxysilane. The mixture may also contain fillers and a small amount of curing catalyst and stabilizer.

Abstract: An encapsulant for an electronic device comprises a silicone resin having a highly colored porphyrin compound doped therein.

Abstract: In the manufacture of encapsulated hybrid circuits from a substrate having a plurality of such circuits contained thereon, individual devices are first mounted on the circuit, encapsulant having a yield point stress and viscosity so as not to creep or flow is applied around the periphery of each circuit on the substrate so as to form a wall or dam around each such circuit except for the bonding pads for external connection of each circuit, a second encapsulant is then flow coated over the circuit and devices contained thereon within the previously formed wall such that the second encapsulant is retained within the wall. The encapsulants are then cured or dried and the individual encapsulated circuit can then be further processed such as by separating the individual circuits on the substrate and applying external connectors to the bonding pads.

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: An electronic device such as an integrated circuit is encapsulated within a silicone resin formulation having a metallo-porphyrin compound contained therein. The compound is cleaved by HCl to form a porphyrin diacid chloride and a free metal having the capability of chelating chloride ions and hydroxyl groups thereby preventing corrosion and anionic attack of metallic circuit elements and development of unwanted conductive pathways.

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: 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.

Abstract: An electronic device such as an integrated circuit is encapsulated with a silicone resin formulation comprising a polysiloxane having a cryptate ether as part of the backbone of the polymer chain for preventing migration of cations, e.g., sodium and potassium.

Abstract: An electronic device having a silicone encapsulant includes a 12-crown or 15-crown ether in the encapsulant for preventing migration of sodium or potassium ions.

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.

Abstract: A method of repairing pin holes in a defective photomask such as one comprising a patterned chromium film on a glass substrate comprises depositing an adhesion promoting film such as siloxane on the surface of the photomask, then depositing a solvent soluble layer such as a photoresist layer over the adhesion promoting layer, a window is then formed through the layers and underlying photomask in the area of the pin hole by burning through these layers by means of a laser. The exposed areas of the window are etched and a metallic film is deposited over the exposed surfaces. Finally, the photomask is treated with solvent for removing the solvent soluble photoresist which also causes the metal film deposited thereon to be removed in all areas except the area of the window.

Abstract: A method of removing a cured epoxy from a surface is disclosed. The method comprises treating at least the epoxy with a suitable swelling agent to swell the epoxy. The swelled epoxy is then treated with an oxidizing agent to oxidize the swelled epoxy. The oxidized epoxy is then treated with an etchant comprising sulfuric acid to remove the epoxy from the surface.