Olin Corporation

Swiss Aluminium Ltd.

Gbc Metals, LLC

Julius C Fister

John F Breedis

Szuchain F Chen

Jacob Crane

Deepak Mahulikar

Joseph Winter

Arvind Parthasarathi

Frank N Mandigo

Satyam C Cherukuri

John G Cowie

Christopher P Laurello

Derek E Tyler

Michael J Pryor

Kenneth E Woodard, Jr

Sankaranarayanan Ashok

William L Brenneman

George C Mei

David L Fair

Robert A Dean

Abid A Khan

Nina Yukov

Andrew Vacco

Brian E O'Donnelly

A James Brock

Sheldon H Butt

Igor V Kadija

Andrew J Brock

Ronald N Caron

William C Setzer

Chung-Yao Chao

George J Muench

Narendra N Singhdeo

Dennis R Brauer

Efraim Sagiv

Ashok Sankaranarayanan

Bruce M Guenin

David D McDevitt

Leonard R Howell

Jack Crane

Gerald N Violette

Mark N Pearman

Christoper P Laurello

Dale L Bender

Leon Cox

Gary L Diehl

Andrew J Vacco

James A Brock

Chen Szuchain

William L Brennemann

The present invention is directed to a coated substrate, comprising: an antitarnish layer deposited on a substrate in an amount effective to prevent tarnishing of said coated substrate; and an outer layer deposited onto said antitarnish layer, said outer layer comprising tin or tin alloys having at least 50% by weight tin. The present invention is also directed to coated substrates having a concentration gradient of antitarnish agent diffused into the coating, as well as methods of forming such coated substrates.

Tarnish deterring tin coating

The present invention is directed to a water-based adhesive composition, comprising an admixture of: (A) about 5 to about 80 wt % of an aqueous polyester polyurethane dispersion; and (B) about 95 to about 20 wt % of an aqueous aliphatic polyurethane dispersion. The present invention is also directed to a method of adhering a workpiece or adherent to a substrate using the above water-based adhesive composition.

Water-based adhesive

A composite material includes a structural carrier layer and a relatively thin metal foil layer separated by a release layer. The release layer, that may be an admixture of a metal such as nickel or chromium and a non-metal such as chromium oxide, nickel oxide, chromium phosphate or nickel phosphate, provides a peel strength for the metal foil layer from the carrier strip that is typically on the order of 0.1 pound per inch to 2 pounds per inch. This provides sufficient adhesion to prevent premature separation of the metal foil layer from the carrier layer, but easy removal of the carrier layer when desired. Typically, the metal foil layer is subsequently bonded to a dielectric and the carrier layer then removed. The metal foil layer is then imaged into circuit features in the manufacture of printed circuit boards and flexible circuits.

Copper foil composite including a release layer

A tin coated electrical or electronic component has enhanced resistance to oxidation and tarnishing as well a smaller increase in contact resistance when exposed to elevated temperatures. These benefits are achieved by depositing a relatively thin, on the order of 5-50 angstroms thick, layer of zinc on the tin coating prior to heating. A subsequent step of heating the sample to a temperature and time effective to convert all free tin to an intermetallic imparts the additional advantage of reducing the coefficient of friction.

Tin coatings incorporating selected elemental additions to reduce discoloration

A method of introducing an anti-tarnish agent into the matrix of a tin coating to reduce oxidation and/or yellowing of the tin coating. The agent is preferably zinc, indium or phosphorous and can be deposited in a molten form to alloy with the existing tin coating. Alternatively, the existing tin coating may be exposed to a chemical bath including the agent and later heated to reflow the tin coating and agent thereby incorporating the agent into the matrix of the tin coating.

Tin coatings incorporating selected elemental additions to reduce

An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the formation of a copper/tin intermetallic and the resultant depletion of the free, unreacted, tin utilized as an oxidation and corrosion barrier, a barrier is interposed between the substrate and the coating. In a first embodiment, the barrier is formed from multiple constituent layers, at least one of which is copper. The thickness ('y') of the copper layer is dependent on the anticipated service temperature and satisfies the equation y=(-1.52+0.0871x+0.00859 t).+-.50% where t=anticipated time at the service temperature, x=anticipated service temperature (Celsius), and y=the thickness of the copper layer in microinches. In a second embodiment, the barrier layer is formed from one or more constituent layers, at least one of which is iron or iron base.

Multi-layer diffusion barrier for a tin coated electrical connector

An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the diffusion of copper from the substrate into the coating layer and the consequential formation of a brittle tin/copper intermetallic, a barrier layer is interposed between the substrate and the coating layer. This barrier layer contains from 20% to 40%, by weight, of nickel and is preferably predominantly comprised of copper. In one embodiment, an intermetallic layer selected from the group (Cu--Ni).sub.3 Sn, (Cu--Ni).sub.6 Sn.sub.5, Cu.sub.3 Sn, Cu.sub.6 Sn.sub.5 is disposed between the barrier layer and the tin base coating layer.

Tin coated electrical connector

An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the diffusion of copper from the substrate into the coating layer and the consequential formation of a brittle tin/copper intermetallic, a barrier layer is interposed between the substrate and the coating layer. This barrier layer contains from 10% to 70%, by weight, of nickel and is preferably predominantly comprised of copper. In one embodiment, an intermetallic layer selected from the group (Cu--Ni).sub.3 Sn, (Cu--Ni).sub.6 Sn.sub.5, Cu.sub.3 Sn, Cu.sub.6 Sn.sub.5 is disposed between the barrier layer and the tin base coating layer.

There is provided a machinable .alpha.+.beta. brass containing bismuth and phosphorous. By maintaining the phosphorous content within a critical range, the alloy exhibits good elevated temperature tensile elongation in the temperature range of 100.degree. C.-350.degree. C. without a decrease in machinability due to phosphide formation. In preferred embodiments, the alloy further contains a tin addition for enhanced corrosion resistance. The combination of tin and phosphorous provides enhanced corrosion resistance to the alloy than could be predicted from either addition alone.

Corrosion-resistant bismuth brass

The formation of whiskers during tin or tin-lead solder electroplating of a copper base alloy substrate in a methane sulfonate solder plating bath is inhibited by passivating the surface of the substrate prior to electroplating. Preferred passivating solutions include an aqueous solution of sodium dichromate and phosphoric acid, and an aqueous solution of chromic acid and phosphoric acid. Passivation is preferably followed by treatment with a basic solution having a pH of at least 8.

Treatment to reduce solder plating whisker formation

A palladium alloy of the form Pd.sub.x M.sub.y M'.sub.z where M is at least one element selected from the group consisting of silicon, iron, nickel, copper, chromium, cobalt, boron and aluminum and M' is at least one element selected from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten is provided. The alloys exhibit oxidation resistance and low electrical contact resistance and are particularly suited for electrical applications such as coatings for electrical contacts or connectors. In a preferred embodiment, the alloy is palladium/niobium containing from about 5 to about 10 atomic percent niobium.

Palladium alloys having utility in electrical applications

A method for depositing a composite coating on a substrate is provided. The coating contains a mixture of ductile metal particles and a uniformly dispersed polymer particles. The polymer is present in a concentration effective to reduce frictional forces. The coating mixture is compacted such as by isostatic pressing, formed into strips and then clad to the substrate. One preferred coating contains 0.5 weight percent polytetrafluoro-ethylene in a tin matrix.

Method of making coated electrical connectors

A palladium alloy of the form PdNbM where M is at least one element selected from the group consisting of silicon, iron, nickel, copper, cobalt, boron and aluminum is provided. The alloys exhibit oxidation resistance and electrical contact resistance and are particularly suited for electrical applications such as coatings for electrical contacts or connectors. In a preferred embodiment, the alloy contains from about 5 to about 10 atomic percent niobium.

There has been provided an electrical component having resistance to oxidation and wear. The component has a copper or copper alloy substrate coated with a relatively thick layer of silver. A thin layer of gold may be deposited on the external surface of the silver coating layer to improve oxidation resistance, lubricity and to serve as a diffusion barrier.

Silver-coated electrical components

Growing community of inventors

Hamden, CT, United States of America

Julius C Fister