Dow Corning Corporation

Shin-ichi Hirano

Ronald H Baney

Len A Harris

John H Gaul, Jr

Carl J Bilgrien

Chi-long Lee

Loren A Haluska

Lawrence D Fiedler

Gary T Burns

Duane R Bujalski

Keith W Michael

Ollie W Marko

Grish Chandra

Keith D Weiss

Cecil L Frye

Leo Tarhay

Frank K Chi

Debora F Bergstrom

Leslie Earl Carpenter, Ii

Dennis W Broderick

Bruce H Justice

Sarah S Snow

A silica coating is formed on an electronic substrate by applying a silazane polymer on the substrate and converting it to silica by heating in an oxidizing environment. The resultant thick planarizing coatings are useful as protective coatings and dielectric inner layers.

Coating electronic substrates with silica derived from silazane polymers

This invention relates to a low temperature method of converting coatings of hydrogen silsesquioxane resin or hydrolyzed or partially hydrolyzed R.sub.X Si(OR).sub.4-X to ceramic silica coatings. The method comprises applying a silica precursor coating to a substrate, exposing the coating to an environment comprising an amine and subjecting the coating to a temperature sufficient to yield the ceramic coating. The methods of the invention are particularly applicable to applying coatings on electronic devices.

Amine catalysts for the low temperature conversion of silica precursors

The present invention relates to soluble perhydrosiloxane copolymers of the formula [H.sub.2 SiO].sub.x [HSiO.sub.3/2 ].sub.y wherein the mole fractions x and y total 1. In addition, the present invention relates to the use of these novel copolymers as coating materials, especially for use on electronic devices.

Perhydrosiloxane copolymers and their use as coating materials

The silacyclobutane functional polydiorganosiloxane copolymers of the invention have the following structure: ##STR1## wherein M is selected from ##STR2## wherein R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, and R.sup.f are independently monovalent radicals selected from the group consisting of hydrogen, hydrocarbon, or substituted hydrocarbon; m and x are integers of from 0 or more; n is equal to 1; and p is an integer greater than 0; with the proviso that there is at least one silacyclobutane group in the copolymer. The copolymer can be made by reacting a hydroxyl endblocked polydiorganosiloxane with either a difunctional chain extending silacyclobutane or with a monofunctional chain stopper, or a mixture of chain extender and chain stopper. The copolymer can be made into curable compositions by use of suitable catalyst.

Silacyclobutane functional polymers and their production

A method is disclosed for preparation of superconductive substances, and in particular, those comprising a rar earth element, barium (Ba), copper (Cu) and oxygen, having a composition represented by the general formula: LnBa.sub.2 Cu.sub.3 O.sub.7-.delta. in which Ln represents a rare earth element and .delta. has a value of about 0 to 0.5. The method includes forming a solution containing an organic compound of a rear earth element, an organic barium compound and an organic copper compound in an organic solvent, homogenizing the resulting solution, stripping the organic solvent from the homogenized solution by evaporation to give a precipitate and pyrolyzing the precipitate to obtain the superconductive substance. The precipitate may also be formed as fibers or films prior to pyrolysis.

Process for preparing ceramic superconductive substances

The specification discloses forming ceramic films, and especially high temperature superconductor films, by dissolving ceramic precursor metal iodides in organic solvents, applying them to a substrate, evaporating the solvent and pyrolyzing and annealing the resulting ceramic precursor metal iodide films.

Method for forming ceramic materials, including superconductors

Novel silacyclobutanes useful as silylating agents and a process for their preparation are provided. The process comprises reacting a halogen substituted silacyclobutane with a silylating reagent to exchange the halogen substituents with groups on the silylating reagent. The novel compounds are of the formula ##STR1## wherein R' is a monovalent substituted or unsubstituted hydrocarbon radical or Y group; R' and R'' are independently hydrogen, monovalent substituent or unsubstituted hydrocarbon radical; and Y is selected from: ##STR2## and the disubstituted silacyclobutane wherein both Y and R' are ##STR3##

Silacyclobutanes

Novel silacyclobutanes useful as silylating agents and a process for their preparation are provided. The process comprises reacting a halogen substituted silacyclobutane with a silylating reagent to exchange the halogen substituents with groups on the silylating reagent. The novel compounds are of the formula ##STR1## wherein R' is a monovalent substituted or unsubstituted hydrocarbon radical or Y group; R' and R'' are independently hydrogen, monovalent substituted or unsubstituted hydrocarbon radical; and Y is selected from: ##STR2## and the disubstituted silacyclobutane wherein both Y and R' are ##STR3##

Process for preparation of silacyclobutanes

A method of forming at low temperatures silicon- and nitrogen-containing ceramic or ceramic-like coatings for the protection of electronic devices. The coatings are produced by the ceramification at temperatures of, or below, 400 degrees Centigrade of preceramic silicon nitrogen-containing polymer coatings deposited from a solvent solution. The coatings are useful for planarizing the surfaces of electronic devices and for passivation.

Sin-containing coatings for electronic devices

A method of preparing ceramic materials with increased levels of crystalline SiC and/or Si.sub.3 N.sub.4 is described. The method consists of firing a mixture of a R.sub.3 SiNH-containing silazane polymer and an inorganic compound selected from the group consisting of iron compounds, cobalt compounds, nickel compounds, and copper compounds to an elevated temperature of at least 750.degree. C. under an inert atmosphere or in a vacuum until a ceramic material with increased levels of crystalline SiC and/or Si.sub.3 N.sub.4 is obtained.

Ceramic materials with increased crystallinity from silazane polymers

A method is disclosed for the preparation of ceramic materials with reduced oxygen levels from polycarbosilanes by the pyrolysis of a mixture of a polycarbosilane, a hydrosilylation catalyst, and an unsaturated compound selected from the group consisting of reactive diolefins, reactive alkynes, polyolefins, vinylsilanes, and unaturated siloxanes where the mixture is rendered infusible prior to pyrolysis by heating to relatively low temperatures in an inert atmosphere. This invention is especially well suited for the production of ceramic fibers from polycarbosilanes.

Ceramic materials from polycarbosilanes

A method is disclosed for increasing the ceramic yield of a ceramic material obtained by firing a R.sub.3 SiNH-containing silazane polymer to an elevated temperature in an inert atmosphere or in a vacuum. The method involves adding certain metallic compounds to the R.sub.3 SiNH-containing silazane polymer prior to firing. Metallic compounds which increase the ceramic yield include ruthenium compounds, palladium compounds, silver compounds, indium compounds, iridium compounds, and platinum compounds.

Ceramic materials from silazane polymers

What is disclosed is an improved method of preparing silicon carbide which is characterized by the preparation of a specific pre-silicon carbide polymer. The method allows the preparation of silicon carbide from specific polysilane polymers without the cumbersome extractions and purifications found in the newer methods of silicon carbide preparation.

Method for preparing silicon carbide

What is disclosed are new alumina-containing organosilicon resins which are useful as corrosion inhibiting coatings on metal substrates. One such useful composition is a combination of 2.5 weight percent alumina; 87.1 weight percent CH.sub.3 SiO.sub.3/2 and 10.3 weight percent colloidal silica in an aqueous-alcoholic solution at about twenty percent solids.

Alumina-containing organosilicon resins

Pre-polymers which are aminated methylpolysilanes are useful for the preparation of fine grained silicon carbide ceramic materials and silicon carbide-containing ceramics. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.

Growing community of inventors

Midland, MI, United States of America

Ronald H Baney