Abstract: Aqueous, silicate free, cleaning compositions of about pH 9 or below and method of using the cleaning compositions for cleaning microelectronic substrates, which compositions are able to essentially completely clean such substrates and produce essentially no metal corrosion of the metal elements of such substrates. The aqueous cleaning compositions of this invention have (a) water, (b) at least one of ammonium and quaternary ammonium ions and (c) at least one of hypophosphite (H2PO2?) and/or phosphite (HPO32?) ions. The cleaning compositions also may contain fluoride ions. Optionally, the composition may contain other components such as organic solvents, oxidizing agent, surfactants, corrosion inhibitors and metal complexing agents.

Abstract: Process for cleaning wafer substrates of metal contamination while maintaining wafer smoothness by contacting the wafer substrates with a cleaning composition comprising an aqueous, metal ion-free base and an amphoteric surfactant and optionally a metal complexing agent and a propylene glycol ether organic solvent.

Abstract: Aqueous alkaline cleaning solutions for cleaning microelectronic substrates and maintaining substrate surface smoothness comprise a metal ion free base, a nonionic surfactant and a component to reduce or control the pH of the cleaning solution to a pH within the range of from about pH 8 to about pH 10.

Abstract: The invention is a method for providing an electrically conductive path through a substrate. It is especially useful for electrically connecting together electrically conductive paths (25) on opposite sides of a circuit board (20). The method is characterized by the steps of forming a passage (21) through a substrate (20) that connects to at least one conductive path (25) on each side of the substrate (20), filling the passage (21) with an electrically conductive powder (10), applying pressure with a die (30) to obtain a compacted powder (11) in the passage (21), and then heating the compacted powder (11) to a temperature that increases the conductivity and ductility of the compacted powder (11) and its adhesion to the substrate (20) without adversely affecting the shape or condition of the substrate (20).

Abstract: The invention relates to an improvement in dielectric type printed circuit boards having wells for mounting active circuit components on a metal substrate for heat dissipation. The improvement resides in a hermetic seal for the printed circuit board which includes a lid hermetically sealed to the top surface of the circuit board, as well as a chemically vapor deposited coating on the dielectric around the active components to prevent seepage of water and oxyen through the lid edges and into the well regions which would otherwise be detrimental to the active components.

Abstract: A high circuit density printed circuit board is manufactured on a metal substrate by building a layer of photoimageable dielectric on the metal substrate and then imaging the dielectric in a manner so as to create wells for active components which are mounted directly on the metal substrate for the purpose of heat dissipation. The build up of the dielectric layer can be improved to provide circuit traces such as, for example, buried coaxial cables prior to the imaging process to achieve even higher density with conventional circuit boards.

Abstract: This method relates to a process for manufacturing printed circuit boards in which a metal coating is sputtered onto certain regions of a substrate. Adhesion of the sputtered material is excellent. Surface preparation of the substrate and etching thereof prior to sputtering are virtually eliminated. Films deposited by sputtering exhibit uniform coverage and thickness.

Abstract: This method relates to a process for manufacturing printed circuit boards having high density, fine lines of printed conductors. Extremely straight, vertical walls are formed in the radiation light curable dielectric material.

Abstract: The invention relates to a novel process of etching a metal clad substrate which comprises contacting said substrate with one or more reactive gases, as for example ozone, to form one or more reaction products on the surface of the said metal which are more friable than said metal, and striking said reaction products with a plurality of abrasive particles.

Abstract: Separate deposits of trona or nahcolite ore are solution mined with two solvents, aqueous sodium hydroxide and aqueous hydrogen chloride. Aqueous sodium carbonate solution is withdrawn from the region of the NaOH-treated ore deposit, for recovery of soda ash. Aqueous sodium chloride brine is withdrawn from the region of the HCl-treated ore deposit and introduced to an electrodialysis cell to regenerate the two solvents and thereby continue the solution mining cycle.

Abstract: Improved process for preparing sodium carbonate from crude trona without carbon column scaling by evaporating a portion of water from a clarified sodium carbonate solution to crystallize sodium carbonate crystals therefrom, separating the sodium carbonate crystals from the crystallizer liquor, passing only the crystallizer liquor which contains organic impurities through a carbon column to reduce the organic impurity concentration therein, and evaporating a portion of water from the carbon treated crystallizer liquor to crystallize additional sodium carbonate crystals.

Abstract: In the production of SALP tetrahydrate wherein sodium carbonate and aluminum hydroxide are added to aqueous phosphoric acid, the viscous reactive mixture is agitated with water to free the SALP tetrahydrate crystals from the gelatinous matrix. The crystals are recovered by filtration or centrifugation.

Abstract: Anhydrous sodium carbonate is crystallized from saturated aqueous sodium carbonate solutions at temperatures in the range of 104.degree. to below 109.degree. C. by adding to the solution very small proportions of additives which function to reduce the transition temperature of monohydrate to anhydrous sodium carbonate.

Abstract: Tributoxyethylphosphate is useful in controlling foam produced during the evaporative crystallization of calcined trona solutions. The chemical is effective at low concentrations, i.e. 1 to 30 ppm, and does not significantly alter the crystal habit of the sodium carbonate crystals.

Abstract: This invention involves a process for producing high bulk density sodium carbonate from crude trona wherein sodium carbonate monohydrate purge streams containing high amounts of organic impurities are passed to an anhydrous crystallizer operated at temperatures above about 109.degree.C wherein anhydrous sodium carbonate crystals are formed having high bulk densities of about 60 to about 80 lbs/ft.sup.3.