Alliedsignal Inc.

Motorola Corporation

Allied Corporation

Uop Lcc

The Signal Companies, Inc.

James A Wrezel

Joseph J Zupancic

Andrew M Zweig

Allyson J Beuhler

Robert C Pfahl, Jr

Lawrence R Hagner

Jean M Frechet

Anthony J Polak

Jeffrey P Conrad

John L Leicht

William R Bratschun

Allyson Beuhler

Solder pastes presently harden or congeal over time. This results in wasted solder paste and in production down time. This hardening is a result of the long polymer chains created by the dicarboxylic acid in the activator and the indium (In) or tin (Sn). A solder paste is described in which the metal alloy is coated by an agent that inhibits the reaction with the dicarboxylic acid. One solution involves coating the metal alloy powder with monocarboxylic acids, which truncate the polymer chain. Another manner for truncating the polymer is to coat the metal alloy powder with complexing agents. The metal alloy powder can also be coated by a stable metal such as lead (Pb), gold (Au), silver (Ag), bismuth (Bi), palladium (pd), platinum (Pt), a silver palladium alloy (AgPd) or a silver platinum alloy (AgPt).

Solder paste

A distillable, non-azeotropic solvent mixture for electronic assembly cleaning in order to adequately remove solder flux and other residues traditionally removed using CFC-based azeotropes. The mixture is heated to at least the boiling point of component A but less than the boiling point of component B. Component A vaporizes (102), forming a vapor layer above the mixture (103). Condensing elements (101) near the top of the cleaning apparatus condense the vapor (102), returning it to the heated mixture (103) to be vaporized again. The assembly (104) to be cleaned is lowered through the vapor and then immersed in the mixture (103) before being positioned in the vapor (102).

Method for electrical assembly cleaning using a non-azeotropic solvent

Non-azeotropic solvent composition for cleaning and defluxing electrical

The apparatus of the present invention uses a vessel with a sump for containing a liquid (103). The vessel has one or more downward angled openings (101). A heating device (104) boils the liquid to produce a vapor and a condensing apparatus (102), in the opening or in a separate chamber, prevents any vapor from exiting the apparatus. The apparatus contains a condensable liquid having a vapor density less than that of the ambient atmosphere by producing a stably stratified interface between the condensable vapor and the ambient atmosphere. The apparatus can be used for such manufacturing processes as cleaning or coating with vapors that are less dense than air.

Vapor containment apparatus

Thermosetting resins which are essentially vinylbenzyl end-capped ethers of the oligomeric condensation products of certain dihydric phenols and formaldehyde are readily polymerized to give an extensively cross-linked polymer particularly useful in printed circuit boards and similar laminates. Effective cost reduction may be enjoyed by replacing up to 50% of the vinylbenzyl moieties by other groups, such as alkyl and benzyl groups, without destroying the usefulness of the resulting thermosetting resins. The vinylbenzyl ether product from bisphenol-A is especially recommended.

Styrene terminated multifunctional oligomeric phenols as new

Styrene-terminated polyethers of polyphenols may be used as components in a laminate when coated on a reinforcement or substrate. The poly(vinyl benzyl ether) may be prepared by reacting a bisphenol with an alpha,omega-diahlosubstituted alkane and thereafter reacting the resultant product with vinyl benzyl chloride. The laminates which are prepared from these compounds may be employed in electric or electronic circuit boards and will possess desirable electrical and thermal properties as exemplified by a moderate-to-high glass transition temperature and a low dielectric constant.

Styrene-terminated polyethers of polyphenols

Novel compositions of matter comprising semi-interpenetrating polymer networks resulting from the reaction between a poly(vinyl benzyl ether) of a polyphenol and engineering condensation thermoplastic may be used as components in a laminate when coated on a reinforcement or substrate. The resulting laminates which may be employed in electric circuit boards will possess desirable electrical and thermal properties as exemplified by a high glass transition temperature and a low dielectric constant.

Semi-interpenetrating polymer networks

The resins resulting from converting dicyclopentadiene-phenol adducts to their corresponding vinylbenzyl ethers are an excellent matrix in which to embed fibers to produce a composite. Such resins, especially as a blend of materials with varying molecular weight distribution, are amorphous materials whose glass transition temperature is well under the curing temperature, and whose solubility permits solutions with high solids content so as to afford coatings with high resin content. The extensively crosslinked polymer resulting from therma, photochemical, or free radical initiated polymerization has excellent thermal and electrical properties for use in multilayer circuit boards.

Vinyl-benzyl ethers of phenol-dicyclopentadiene adducts as new

Homogeneous thermosetting copolymers comprising a mixture of styrene-terminated tetrakisphenols and compounds containing at least one pendant vinyl group as exemplified by styrene-terminated tetrakisphenol ethane and styrene-terminated bisphenol A will possess desirable characteristics such as low dielectric constants and high glass transition temperatures. These polymers may be utilized as a component in laminates or circuit boards which are employed in relatively complicated pieces of electronic equipment.

Homogeneous thermosetting copolymers

High temperature thermosetting resin compositions which may be used as a polymer matrix for a printed circuit board will comprise a terpolymer of an ethylenically monosubstituted unsaturated monomer in which said substituent is an aromatic moiety such as styrene, an ethylenically alpha,beta-disubstituted unsaturated monomer in which each substituent is an aromatic or benzylic moiety such as acenaphthylene and a glycidyl ester of a monoethylenically unsaturated acid such as glycidyl methacrylate cross-linked with a copolymer of an anhydride of a dibasic olefinic acid such as maleic anhydride and an ethylenically monosubstituted unsaturated monomer in which said substituent is an aromatic moiety such as styrene.

High temperature thermosetting resin compositions

Thermoset polymers of styrene terminated tetrakis phenols may be prepared from resins which possess the generic formula ##STR1## in which R is selected from the group consisting of alkyl, cycloalkyl, alkaryl and substituted alkaryl radicals and X is independently selected from the group consisting of hydrogen and halogen atoms. These polymers will be utilized as a component in laminates on circuit boards which are employed in relatively complicated pieces of electronic equipment.

Thermoset polymers of styrene terminated tetrakis phenols

Novel high temperature thermoset terpolymers may be synthesized by reacting an alpha-substituted olefin, an alpha,beta-disubstituted olefin and a dual function monomer followed by cross-linking the resultant polymer with a low molecular weight multifunctional amine as the cross-linking agent in the presence of a catalyst. The resulting cross-linking agent is then cured at an elevated temperature to provide the desired terpolymer. This compound will possess desirable properties such as a low dielectric constant which renders it applicable for use as circuit board laminates.

High temperature thermoset terpolymers

Electrochromic display devices which will maintain coloration after the electric current has been removed will comprise an electronic conductor consisting of a support which may be electrically conductive per se or contain an electronic conductor thereon, an electrochromic material in contact with said conductor, a solid electrolyte comprising a blend of an organic polymer and a heteropoly acid or salt thereof disposed on said electrochromic material and a counter-electrode in contact with the solid electrolyte. By utilizing this type of solid electrolyte, it is possible to obtain a display device which may range from about 5 to about 100 microns in thickness.

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Buffalo Grove, IL, United States of America

James A Wrezel