Abstract: A carrier sub-assembly having improved dimensional stability for applications in electronic and optoelectronic industries is disclosed. The carrier sub-assembly, when housed in an optoelectronic package, for example, includes a metal substrate and an insert which support optoelectronic devices that are optically coupled to one another. The insert allows for the attachment, for example, via laser spot welding, of electronic and optoelectronic devices where direct attachment of a device to the metal substrate is not practical. In one embodiment of the present invention, the carrier sub-assembly includes Kovar™ insert that is attached to copper/tungsten metal substrate in a recess of the metal substrate so that at least a portion of the insert is attached to the metal substrate in three dimensions. A fiber optic assembly is secured to the insert by a Kovar™ clip.

Abstract: The present invention provide a plurality of layered substrates for semiconductor packages. The substrates include, for example, a metal matrix composite layer and at least one carrier layer having a coefficient of thermal expansion and a thermal conductivity greater than the metal matrix composite. In the preferred embodiment, the metal matrix composite includes between approximately 50% to 95% refractory metal with the remainder copper. Suitable carrier layer materials include, for example, copper. So configured, the layered substrates provide improved rigidity and thermal characteristics for matching with ceramic materials.

Abstract: In a process for cleaning one or more articles in the vapor phase of an organic solvent the solvent vapor is fed into a cleaning chamber (1) wherein an absolute pressure of 200 mbar or less is maintained and the cleaning is conducted at a temperature at or above the flash point of the organic solvent. A preferred apparatus for conducting the cleaning process contains a cleaning chamber (1), two storage tanks (2 and 3), an evaporator (4), a heating device (5) and a condenser (6). These devices are connected by means of a conduit system which is equipped with a vacuum pump (7), two pumps (8 and 9) and valves (12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22). Inlet air (11) can be fed into the cleaning chamber (1). Waste gas (10) can be removed from the apparatus by means of the vacuum pump (7).

Abstract: The invention is directed to a process for protecting the edges of a panel by applying a non-sagging polyurethane composition to the edges of said panel, and allowing the composition to cure.

Abstract: Combustion modified foams are produced by reacting an organic aromatic polyisocyanate with an isocyanate reactive compound in the presence of a blowing agent and Mg(OH).sub.2. The Mg(OH).sub.2 is generally used in a quantity of from 4-100 parts by weight based on the foam taken as 100 parts by weight. Mg(OH).sub.2 having a particle size of from 0.5-50 .mu.m is preferably used. The foams produced by the process are particularly useful in construction applications.

Abstract: Flame resistant polyurethane foams are made by reacting a polyisocyanate with a specific polyol composition. This polyol composition is made up of (a) at least 10 wt. % of a polyether formed by the addition of alkylene oxide(s) to 2,3- and/or 3,4-tolylenediamine having an OH number of from 400 to 520, (b) at least 20-50 wt. % flame retardant containing phosphorus and/or halogen, (c) 5-10 wt. % chain lengthening or cross-linking agent, (d) surface active agents, (e) water and (f) 0-30 wt. % polyhydroxyl compound(s) other than (a) having a molecular weight of from 300 to 10,000.

Abstract: Rigid, closed-cell, flame-resistant polyurethane foams are produced by reacting a polyol mixture with a polyphenyl-polymethylene-polyisocyanate in the present of a catalyst system. The polyol mixture includes: (1) from 25 to 43 wt % flame proofing agent, (2) from 5 to 50 wt % sucrose polyether having an OH number of from 350 to 550, (3) from 0 to 30 wt % amine initiated polyethers having an OH number of from 400 to 800, (4) from 0 to 30 wt % other polyether or polyester having an OH number of from 150 to 600, (5) from 4 to 13 wt % glycerol, (6) from 0.5 to 3 wt % silicone stabilizer and (7) from 0.05 to 1.5 wt % water. The catalyst system is made up of at least two components selected from tertiary amines, alkali metal carboxylates, quaternary ammonium carboxylates and organic tin compounds. The reactants are employed in quantities such that the NCO to OH equivalent ratio is from 1.07 to 1.45 (the isocyanate-index is from 1.07 to 1.45).

Abstract: The isolation voltage of an optocoupler including a light transmissive inner region and a reflective or opaque outer region, the interface between such regions being intersected by input and output terminals, is improved by providing a layer of breakdown voltage enhancing material at the interface. In accordance with a preferred embodiment of the invention, a layer of glass frit is provided at the interface, the particles comprising the frit extending into each of the regions.