Raytheon Company

Hughes Aircraft Company

Steven E Lau

Ralph D Hermansen

Thomas K Dougherty

Lynn E Long

T Kirk Dougherty

William J Wolfgong

Cindy W Ma

Mark A Weaver

E Dean Johnston

Steffanie S Ung

Christopher T Snively

Stephen L Schrader

Steven A Tunick

Teresa L Rosales

Deborah S Huff

David J Vachon

A curable composition including: an epoxy resin; and an amine curing component including: an aromatic amine curing agent; and a solubilizer including an aliphatic amine, a cycloaliphatic amine, a non-volatile primary alcohol, non-volatile solvent or a mixture thereof. An electronic assembly including: a substrate; an underfill including a cured product of the curable composition on the substrate; and a ball grid array on the underfill is also disclosed.

Reworkable epoxy resin and curative blend for low thermal expansion applications

The disclosure relates to an X-ray opaque coating containing an epoxy resin including an iodinated phenol covalently bonded to a glycidyl ether. Iodinated phenol covalently bonded to a glycidyl ether may include iodinated bisphenol A, such as tetraiodobisphenol A, a glycidyl ether of mono-iodophenol, bis-iodephenol, tri-iodophenol, or combinations thereof. The coating may include an X-ray opaque inorganic filler. The disclosure also relates to an electronic component including a substrate and at last one device coupled to the substrate with an obfuscation layer disposed over the substrate for obscuring the device from an X-ray source. The obfuscation layer may include an X-ray opaque coating. The disclosure additionally relates to- a method of obscuring at least a portion of an electronic component by depositing an obfuscation layer that may include an X-ray opaque coating and a method of forming an X-ray opaque coating.

X-ray opaque coating

Flexible epoxy-based adhesive compositions which remain Theologically stable at room temperature in an uncured state comprise: (a) at least one flexible polyepoxide resin having a hardness not exceeding a durometer Shore D reading of 45 when cured with a stoichiometric amount of diethylene triamine (&ldquo;DETA&rdquo;); and (b) a substantially stoichiometric amount of at least one latent epoxy resin curing agent. Optionally, the adhesive composition may also incorporate one or more semi-flexible resins. Other optional components include fillers, thixotropic agents, and flexibilizers. The adhesive composition provicdes an epoxy-based adhesive composition that is storable for weeks as a single component mixture at room temperature, curable at temperatures ranging from about 100&deg; C. to 125&deg; C. in less than two hours, and flexible upon curing to temperatures as low as minus 50&deg; C., exhibiting a durometer Shore A of less than about 95.

Adhesive of flexible epoxy resin and latent dihydrazide

Amine adducts comprising a reactive amine curing agent containing an aromatic silane epoxy along with improved coatings made by combining the amine adduct with additional epoxy material. The amine adducts, when formulated and cured with an epoxy material, cures in several hours and gives a protective coating material that cures without blush or CO.sub.2 incorporation. Specific embodiments of the amine adduct contain a bisepoxy compound, such as 2,11-bis(3-glycidylphenyl)-2,11dimethyl-2,11-disiladodocane (n=4), for example, while the amine functionalized compound may be ethylenediamine (90.degree. C., 120.2 g, 20 mol) or aminoethylpiperazine, respectively. A number of chemical compounds are also disclosed.

Amine curing agents and epoxy coatings produced using same

A flexible thermally-conductive epoxy-based adhesive composition and method for making the same are provided. The present adhesive composition comprises (a) a polymer mixture comprising at least one polyepoxide resin having a hardness not exceeding a durometer Shore D reading of about 45, when cured with a stoichiometric amount of diethylene triamine ('DETA'), and a substantially stoichiometric amount of at least one latent epoxy resin curing agent; and (b) a thermally-conductive filler. Optional components include secondary epoxy resins, non-reactive flexibilizers, diluents, and processing aids. The present adhesive composition is rheologically stable for weeks or even months at room temperature and is curable in less than one hour at a temperature ranging from about 100.degree. C. to 140.degree. C., whereupon the cured adhesive composition exhibits a durometer Shore A of less than about 90 and a thermal conductivity exceeding 0.4 BTU/hr-ft-.degree. F. (0.7 W/m-K).

Room-temperature stable, one-component, thermally-conductive, flexible

A solid, one-component, flexible epoxy-based composition and method for making the same are provided. The present compositions comprise: (a) an epoxy-terminated prepolymer formed by reacting at least four moles of a polyepoxide resin with approximately one mole of a diamine compound, wherein at least one of the polyepoxide resin and diamine compound is solid at room temperature, and wherein the prepolymer is rheologically stable for weeks as a single component mixture at room temperature and, and (b) a substantially stoichiometric amount of an epoxy resin curing agent selected from the group consisting of a heat-curable, latent epoxy resin curing agent and a room temperature-curable ketimine curing agent. Optional components include thixotropic agents, diluents, fillers, anti-oxidants, and processing aids. The present uncured epoxy-based compositions upon cure, exhibit a durometer Shore D of less than about 45 (or a durometer Shore A of less than about 100).

Epoxy-terminated prepolymer of polyepoxide and diamine with curing agent

A flexible, electrically-conductive, one-component epoxy adhesive composition and method for making the same are provided. The present adhesive composition comprises: (a) at least one polyepoxide resin having a hardness not exceeding a durometer Shore D reading of about 45 when cured with a stoichiometric amount of diethylene triamine; (b) a substantially stoichiometric amount of curing agent including at least one amine-terminated butadiene-acrylonitrile polymer; and (c) an electrically-conductive filler. The epoxy adhesive, upon cure, has a volume resistivity not exceeding about 10.sup.-3 ohm-cm at room temperature and a drop resistance such that a 6-mil-thick (0.015 cm) bond effected by the adhesive can withstand at least six 60-inch (152 cm) drops onto a hard surface. Optional components in the epoxy adhesive include secondary rigid and semi-rigid epoxy resins, secondary amine curing agents, non-reactive flexibilizers, diluents, and processing aids. The adhesive bonds achieved using these epoxy adhesives are non-brittle, flexible, resilient, and drop-resistant, while also exhibiting strong adhesion and good processing characteristics.

Adhesive of epoxy resin, amine-terminated ban and conductive filler

A flexible electrically-conductive epoxy-based adhesive composition and method for making the same are provided. The present adhesive composition comprises: (a) a polymer mixture comprising at least one polyepoxide resin having a hardness not exceeding a durometer Shore A reading of 45, when cured with a stoichiometric amount of diethylene triamine ('DETA'), and a substantially stoichiometric amount of at least one latent epoxy resin curing agent; and (b) an electrically-conductive filler comprising a metal. Optional components include secondary epoxy resins, non-reactive flexibilizers, diluents, and processing aids. The present adhesive composition is rheologically stable for weeks as a single component mixture at room temperature and is curable in less than two hours at a temperature ranging from about 100.degree. C. to 140.degree. C., whereupon the cured adhesive composition exhibits a durometer Shore A of less than 95 and a volume resistivity less than about 10.sup.-2 ohm-cm at room temperature.

Room-temperature stable, one-component, electrically-conductive,

Encapsulant compositions which provide both dry heat and humid heat stability comprise: (a) a first liquid epoxy resin comprising either:

Encapsulant of amine-cured epoxy resin blends

Adhesives and sealants, based on polyurethane reactants, are provided. The one-component frozen premix material of the invention comprises: (a) up to about 60 vol % of at least one filler; (b) about 0.5 to 5 wt % of a thixotrope comprising hydrophobic fumed silica; and (c) the balance a urethane matrix. The urethane matrix comprises at least one polyol that includes at least one carbon-carbon double bond in its backbone and has less than 20 wt % of ether and ester moieties, at least one aliphatic polyisocyanate in stoichiometric amount relative to the polyol, and about 0.01 to 0.1 wt % of an organo-metallic catalyst. The urethanes of the invention can be stored as one-component, frozen, premix materials for a minimum of three months, and, when thawed, can be applied with a spatula or trowel to form non-sag fillets. The cured elastomers are free of voids, tears, or bubbles.

Frozen premix, fillet-holding urethane adhesives/sealants

A superior thermal transfer film adhesive comprises the following composition: (a) at least one aliphatic epoxy resin; (b) a stoichiometric amount of at least one aliphatic polyamine curative; (c) an effective amount of a thixotropic agent, such as fumed silica; and (d) about 20 to 50 volume percent of at least one filler, such as alumina, based on the total of the epoxy resin and the curative. The aliphatic epoxy resin has aliphatic pendant chains of 6 to 20 carbon atoms in length. The curative comprises a long chain aliphatic or cycloaliphatic curing agent for the epoxy resin. Since aliphatic moieties, which are flexible, are used, the glass transition temperature of the resulting cured material is lower than epoxies and plasticizers employing rigid moieties. The adhesive of the invention is novel in attaining high volume resistivity (at least 10.sup.14 ohm-cm at 25.degree. C.), low temperature flexibility (-55.degree. C.), excellent adhesion for maximum thermal transfer, and ease of reworkability.

Superior thermal transfer adhesive

Epoxy-type impregnating compounds, which are useful for electrical potting or encapsulation, plastic tooling, and fiber-reinforced composites, comprise a resin component and a stoichiometric amount of a curative and have a curing temperature of less than about 120.degree. F. (49.degree. C.). The resin component is the diglycidyl ether of bisphenol A, either alone or as a mixture with up to about 15 wt % of at least one reactive monoepoxide diluent or up to about 50 wt % of at least one reactive diepoxide diluent, the diluent having a viscosity of less than about 200 cp. The curative is a mixture of cycloaliphatic diamines, comprising from about 20 to 80 wt % of at least one sterically-hindered cycloaliphatic diamine and the balance at least one sterically-unhindered cycloaliphatic diamine. These epoxy compounds are unique because they can be handled in relatively large bulk without concern for dangerous runaway exotherms. In addition, they result in useful products with a moderate service temperature range, without the necessity of high temperature cures. The advantages of the low temperature cure are lower residual stress in the cured product, better dimensional control in molding, and lower energy expenditure.

Low exotherm, low temperature curing, epoxy impregnants

A thermal transfer adhesive composition which is applied after electronic components have been installed on a printed wiring board, comprising:

Modified polyurethane flow-under thermal transfer adhesive

A flexible epoxy adhesive composition comprising a mixture of a fatty acid modified epoxy resin and an oxypropylene epoxy resin in the ratio of about 1:3 to 1:1. The adhesive paste also includes a stoichiometric amount of a polyamine curing agent, 1 to 20 total liquid weight percent of a plasticizer and 1 to 5 weight percent of microfine silicon dioxide particles. Fillers, such as aluminum oxide and glass beads, are optionally added. This adhesive paste is particularly well suited for use as a flat pack adhesive to provide a releasable bond and is also well suited for use in space applications.

Growing community of inventors

Los Angeles, CA, United States of America

Steven E Lau