Abstract: Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

Abstract: A water-based composition for treating copper or copper alloy surface for lead-free soldering, the composition comprising a compound represented by general formula (1): wherein R1 is hydrogen or methyl, and either R2 and R3 represent chlorine and R4 and R5 represent hydrogen, or R2 and R3 represent hydrogen and R4 and R5 represent chlorine.

Abstract: A conductive ball mounting apparatus and method for holding a conductive ball on the holding face, as has a suction port formed therein, of a holder head thereby to mount the held conductive ball, while interposing a flux therein, on a workpiece. After the end of the mounting action and before a next conductive ball is held, flux removing means for removing the flux adhered to the holding face is brought into abutment against the holding face of the holder head thereby to remove the flux from holding face.

Abstract: A guide wire includes a wire member having a first wire disposed on the distal side of the guide wire, and a second wire disposed on the proximal side from the first wire. The second wire is made from a material having an elastic modulus larger than that of the first wire. For example, the first wire is made from a superelastic alloy, and the second wire is made from a stainless steel. The first wire is joined to the second wire at a welded portion by welding. A coil is disposed on the distal side from the first wire. A cover layer is formed on the outer peripheral surface of the wire member in such a manner as to cover at least the welded portion. The cover layer is made from a material capable of reducing the friction of the cover layer, for example, a fluorocarbon resin or a hydrophilic material, to thereby improve the sliding performance of the guide wire. Such a guide wire is excellent in operationality and kink resistance.

Abstract: A purge gas introduction system for an orbital tube welding setup is provided, configured to inject high purity inert purge gas to the interior volume of a tube or tubular component. An o-ring is interposed between an annular base and an annular ring, their junction forming an annular o-ring groove, each part forming one sidewall, with the o-ring fully recessed within the groove, protecting the o-ring during the insertion and removal of a tube. The annular base and an annular ring are configured to receive a tube terminus. The sidewalls of the o-ring groove are divergent one to the other, wherein as the annular ring is drawn towards the annular base, the o-ring is forced partially out of the groove, forming a substantially leak tight seal between the tube and the o-ring. A purge gas from an external source is transmitted to the annular base through a purge connector, then, in turn, introduced to the interior volume of the tube.

Abstract: A hydrocarbon compound mixed with an organic peroxide is placed between a copper electrode and a solder-coated electrode, and is heated at a temperature of about 300° C. The organic peroxide is exposed to a heating energy and thermally decomposed into an organic peroxide radical whose oxygen-oxygen bond has been released. Since this organic peroxide radical is active, it abstracts hydrogen from the hydrocarbon compound. The formation of a hydrocarbon compound radical is accelerated by the organic peroxide so that even at a relatively low heating temperature, a sufficient amount of a hydrocarbon compound radical can be formed. As a result, an oxide film can be removed from the metal surface even at a relatively low heating temperature by the reduction caused by a hydrocarbon compound radical.

Abstract: A mask is provided for shielding a radially extending edge of an impeller vane during a weld repair process, where the impeller vane extends radially and axially outwardly from a shaft. The mask comprises a hub and a flange. The hub has an outer surface and an opening extending therethrough, and the opening is configured to allow the shaft to extend at least partially therethrough. The flange extends radially outwardly from the hub outer surface and is configured to shroud substantially all of the impeller vane radially extending edge.

Abstract: A protective tape for use while welding together two metal components is provided. The protective tape includes a non-metal carrier sheet that is extensible and substantially flexible such that it closely conforms to irregular surfaces of a metal component. The protective tape also includes a covering on a first side of the carrier sheet that shields the carrier sheet from weld spatter, and an adhesive on a second side of the carrier sheet. A method of welding metal components together using the protective tape is also provided.

Abstract: A flexible articulate tubular device has a shank, a plurality of pivot rings, and a terminus with heat sensors and a fiber optic device. The flexible articulate tubular device is initially positioned, either manually or automatically, near a target weld path with the aid of the fiber optic device. The flexible articulate tubular device is then more precisely articulated to direct the terminus along the target weld path, with the aid of the heat sensors. As such, the flexible articulate tubular device operates in a heat seeking manner to follow the weld bead. Ultimately, a gaseous flux is supplied along the flexible articulate tubular device and toward the target weld path, so as to blast the weld bead with an anti-oxidation shield gas and thereby protect the weld.

Abstract: A stainless steel slab containing B, wherein a protecting material is joined onto at least two faces across the bloom from each other in a stainless steel bloom containing B of 0.3–2.5 mass %, being integrated into one-piece by forming a weld metal comprising a stainless steel with chemical composition that satisfies the relationship expressed by following formulas (1)–(4), and a method to produce a steel product by rolling said slab. Further, it is preferable to interpose an insert material between above stainless steel bloom and above protecting material in bonding process. 15?Cr eq?30,??(1) 4?Cr eq?Ni eq?17,??(2) Cr eq=Cr+1.5 Si+Mo?5 B,??(3) Ni eq=Ni+30 (C+N)+0.5 Mn??(4) Herein, each symbol of a chemical element designates the content (mass %) of relevant chemical element contained in steel.

Abstract: A method for underfilling and encapsulating a flip chip in one step is disclosed. The flip chip is immersed in a polymer bath to apply a coating of the polymer to the surface of the flip chip except for the distal end of the conductive projections on the flip chip electrically conductive pads. The coated flip chip is exposed to ultraviolet light or heat (e.g., IR radiation) to surface cure a skin over the polymer coating. The skin-cured flip chip is placed on a substrate which is then heated to reflow the conductive material from the projections and to cause the polymer from the coating to underfill the flip chip and thermally cure to encapsulate and underfill the flip chip.

Abstract: Temperature-sensitive electrical and electronic components which are connected to a board by soldering during the installation process are protected from the heat during the soldering process in order to prevent permanent damage to the components. The solder connections of the component are thermally coupled to a protection apparatus during the soldering process, so that some of the heat which is introduced into the solder connections during the soldering process is passed to the protection apparatus. The protection apparatus also has a protection sleeve, which surrounds the component in places. The protection sleeve is advantageously composed of a thermally insulated material, and is provided with a coating with a high thermal reflection capability in places on its outer wall which faces away from the component.

Abstract: An improved water soluble protective paste and a method for protecting metal circuits and pads on the surface of an electronic board during the manufacturing steps. A densifier is added to the paste making it easier and more efficient the dispensing of the paste. After deposition the layer is dried until a solid protective film is obtained. An additional advantage obtained by the present invention is that the protective layer can be deposited also by means of an offset printing process, avoiding the use of the stencil and of the screening steps. Screening process is a labourious operation which requires very sophisticated equipment and a very high precision in the design of the stencil. Because of these requirements, screening is an expensive process. On the other hand offset printing is a very simple, cheap and reliable method. In addition, the film forming properties allow the material to create a protective film even with a thin deposited film.

Abstract: A method for coating and an associated assembly including such a coating are provided. The assembly includes a workpiece defining a weld portion, such as a friction weld joint and a heat affected zone. A coating is disposed on the weld portion to at least partially cover the weld portion, thereby providing enhanced corrosion resistance to the workpiece.

Abstract: A method for assembling an optical disk apparatus involves disposing first and second short-cutting terminals at different faces of a housing and in parallel with a laser diode of the apparatus. In a first state of assembling, the first short-cutting terminal is shorted by a solder applied thereon. Thereafter, the apparatus is inspected in a second state of assembling in which the solder is removed from the first short-cutting terminal. After inspection, the second short-cutting terminal is shorted by a solder applied thereon. Subsequently, the solder on the second short-cutting terminal is removed.

Abstract: A non-woven weld blanket for protecting automobile exteriors and interiors and industrial equipment from weld spatter, comprising a needle punched webbing of pre-oxidized, polyacrylonitrile (PAN) fibers. The fabric is assembled using these carbon precursor fibers that have been interlocked by a needle punch process to produce a non-woven and non-plush blanket. The weld blanket is lightweight and is successful at a cost-effective thickness and density. In use, the blanket can be taped to automobile components or industrial equipment to ensure the security and protection of equipment from molten metal spatter near welding locations.

Abstract: An apparatus for aligning and dispensing a plurality of solder columns in an array. The apparatus includes a vibrator and an elongated alignment plate supported on the vibrator. The alignment plate includes a plurality of longitudinal guide grooves. A transparent cover is secured on the alignment plate and shaped to cover part of the guide grooves. A parts feeder is operatively associated with the alignment plate to feed solder columns over the upstream end of the alignment plate. The solder columns are received in the guide grooves and fed toward the downstream end of the alignment plate while the alignment plate is vibrated by the vibrator. The solder columns are arranged in an array within the guide grooves so that a vacuum pickup tool may readily capture the cylindrical body of the solder columns.

Abstract: An apparatus and method for eliminating dross in a solder pot of a soldering machine by converting the dross into usable solder. The conversion apparatus is comprised of an impeller, a shroud, an electric motor for driving the impeller, a vacuum source operatively connected to the shroud, an arrangement of guides immersed in the solder pot for recirculating liquid solder and a chemical de-oxidizing agent. The impeller and shroud are adjacent to a free surface of the dross which forms at the top portion of the liquid solder. The method includes the steps of adding a measured amount of de-oxidizing agent to the solder pot, agitating and recirculating the liquid solder/de-oxidizer mixture with the impeller to break-up the dross into smaller particles and separate the solder from the dross, and removing a residue of the dross by suction as the recirculating mixture passes beneath the shroud.

Abstract: A polymer masking flux for fabricating external contacts on semiconductor components includes a polymer resin, a fluxing agent and a curing agent. The flux is configured to clean contact pads for the external contacts, and to hold the external contacts on the contact pads during a reflow bonding process. The flux is also configured to cure or polymerize, to form donut shaped polymer support members for the external contacts. In addition, the flux is configured to mask conductive traces in electrical communication with the contact pads, and to electrically insulate the external contacts from the conductive traces. The external contacts can be pre-formed solder balls, or deposited solder bumps. In the case of solder bumps, the flux can include solder particles configured to coalesce into the solder bumps.

Abstract: A method for manufacturing an air compressor assembly including, between a tank welding step and a final assembling step, a step of submerging a welded tank into a dip tank that contains cooling liquid treated with a corrosion inhibitor. In a preferred embodiment, in the submerging step, all air access ports of the welded tank are open to allow the cooling liquid to coat both the inside and outside surfaces of the air tank to maximize corrosion inhibitor protection and increase tank cooling rate. The method for manufacturing an air compressor assembly according to the present invention may be used in manufacturing air compressor assemblies in various styles.

Abstract: A method for protecting tin oxide coated solder surfaces against further oxidation and a method for fluxless solder joining of such surfaces is provided.

Abstract: A method of aligning and duplicating alignment includes welding a washer over a larger opening in a hinge once in an aligned position relative to a vehicle door. The door is mounted into an alignment fixture and the hinges are installed over threaded studs extending from the door. The washer is placed onto the threaded stud and tightened against the hinge, covering the larger opening in the hinge. The larger opening in the hinge allows movement of the hinge relative to the door for alignment. The washer defines an opening with a smaller opening sized to provide relatively little clearance for the threaded stud, and thereby maintain alignment between the door and hinge. The washer is permanently attached by a welding operation to allow duplication of door hinge alignment during reassembly.

Abstract: In a soldering method for soldering an electronic component including a palladium or palladium alloy layer formed on a surface of the electronic component and also including a soldering lead terminal onto a printed wiring board including a soldering land and plated through hole, a solder layer containing tin and zinc as main components is formed on the surfaces of the land through hole by a HAL treatment. The lead terminal is inserted and mounted in the through hole. The printed wiring board is brought into contact with jet flows of a solder containing tin and zinc as the main components to thereby supply a solder to the land and through hole.

Abstract: A method of brazing an aluminum or aluminum alloy material, containing brazing an aluminum alloy brazing sheet that has an aluminum or aluminum alloy core material and, being clad on one or both surfaces, a filler alloy layer comprised of an Al—Si-based alloy and contains Mg incorporated at least in a constituent layer except the filler alloy layer, thereby to form a hollow structure whose one surface clad with the filler alloy is the inner surface, wherein the brazing is carried out in an inert gas atmosphere without applying any flux; and an aluminum alloy brazing sheet which satisfies the relationship: (X+Y)?a/60+0.5 and X>Y, wherein a (?m) represents the thickness of the filler alloy layer clad on the core material of the inner side of the hollow structure, and X and Y (mass %) represent the Mg contents of the core material and the brazing material, respectively.

Abstract: The solder paste printing method of the present invention mounts a solder paste containing therein as a solder material a Sn—Zn system solder on a mask, and urges the solder paste to make rolling over the mask from one end thereof toward the opposite thereof by means of a squeegee to thereby fill the solder paste into apertures formed in the mask. At this time, by maintaining moisture contained in the atmosphere surrounding the solder paste at a value equal to or less than a predetermined value, as the solder paste is suppressed from causing an increase in the viscosity thereof due to the reaction with the moisture in the surrounding atmosphere during the solder paste printing process, the rolling ability of the solder paste during the printing process can be kept, and attachment of the solder paste to the squeegee can be prevented.

Abstract: By using an application unit having: a storage chamber for a viscous material; a discharge hole, for the viscous material, provided so as to communicate with the storage chamber, where a viscous-material feeding device for feeding the viscous material to the storage chamber is coupled to the application unit; and a discharge-pressure adjusting device for imparting a discharge pressure to the viscous material stored in the storage chamber, a screen mask having openings corresponding to the application object or the application object itself and the discharge hole of the application unit are brought into contact with each other, either the application unit and the screen mask or the application unit and the application object are moved relative to each other while the discharge pressure is imparted to the viscous material in the storage chamber, and the viscous material is applied onto the application object while the storage chamber is replenished at all times with the viscous material by the viscous-material

Abstract: A method to reduce undesirable outgassing includes bonding at least two optical components with a bonding material and encapsulating the bonding material with a capping material. The capping material inhibits the outgassing of species that would otherwise be emitted from the bonding material to the surrounding. In one example, the bonding material is silicone and the capping material is epoxy.

Abstract: A composition and method for cleaning and conditioning a non-conductive surface defined by a through hole in a printed circuit board (PCB) is disclosed. The through hole surface is contacted with the composition of the invention to provide a cleaned and conditioned surface. The clean and conditioned surface is coated with conductive carbon particles (usually graphite) to provide a carbon-coated surface. The carbon-coated surface is electro plated and then soldered using hot solder. Those surfaces that have been soldered and also treated with the composition of the invention exhibit fewer blow hole problems. The composition of the invention comprises carbonates, binders, and resins, and combinations thereof, that improve the adhesion and coverage of a coating containing graphite to a surface defined by a through hole bore or other substrate. (“Through holes” as used herein refers both to through holes and to vias.

Abstract: Components composed of aluminum or an aluminum alloy with a coating comprising an aluminum-silicon alloy deposited thereon by applying an alkali metal fluorosilicate and heating the resulting treated material. The alloy layer is effectively protected against re-oxidation by a non-corrosive, alkali metal fluoroaluminate layer (e.g. a potassium fluoroaluminate layer) which forms simultaneously.

Abstract: A brazing sheet comprises a thin covering material and a core material as well as an Al—Si alloy brazing material inserted between the thin covering material and the core material. The brazing material further contains Mg, Bi and/or Zn, Sn, In. When the above brazing material is molten in an inert gas atmosphere, this molten brazing material seeps onto the surface of the above thin covering material, whereby the brazing sheet is fluxlessly brazed to joint materials.

Abstract: A method of making a heated injection molding nozzle with an integral tip insert. First, an inner portion, an outer collar portion, and an electrical heating element are made and integrally brazed together in a vacuum furnace using a first nickel alloy brazing material. Then a tip insert is made having a desired configuration and seated in the front end of the inner portion and a second nickel alloy brazing material is applied around it. The second brazing material has a melting temperature which is substantially below that of the first brazing material. The tip insert is then integrally brazed in place by heating them to a temperature above the melting temperature of the second brazing material and below the melting temperature of the first brazing material. In addition to not affecting the metallurgical bonding between the other components, this allows the tip insert to be easily removed for replacement by again heating the nozzle to this same temperature.

Abstract: A method for protecting tin oxide coated solder surfaces against further oxidation and a method for fluxless solder joining of such surfaces is provided.

Abstract: The present invention provides for a squealer tip to include some proportion of a highly oxidation-resistant material, and a method for casting same, such that if any environmental coating were removed, the tip would retain some increased level of environmental resistance. The oxidation-resistant material optionally may also be a high abrasion resistance material, such that recession of the tip due to rubbing against a stator would be reduced. In a preferred embodiment, an abrasion-resistant and/or oxidation-resistant material is placed and suitably anchored into the tip region of a wax precursor used to cast a turbine airfoil. During the casting operation, the abrasion-resistant and/or oxidation-resistant material is not completely melted. As the alloy used to form the majority of the turbine blade solidifies, the abrasion and/or oxidation resistant material is incorporated into the turbine airfoil by the solidification of the alloy around it.

Abstract: Disclosed is a method of manufacturing an aluminium or aluminium alloy joined product, such as a shaped and hollow member, comprising the sequential steps of: (a) providing two parts made of aluminium or aluminium alloy, each part having a peripheral flange; (b) positioning the two parts such that the peripheral flange of one part faces the peripheral flange of the other part to form an assembly, and joining the facing flanges of the two parts by heating.

Abstract: The present method relates to the use of a peelable anti-solder mask as a sealant against potting compound. In certain electrical apparatus, a modular component (300) must be attached to a side of a printed circuit board (PCB) (110) which has previously been exposed to solder. Solder ‘pick up’ is prevented by application of a removable mask (202) over areas of the exposed side of the PCB (110) which will receive the modular component (300). Potting compound is used to protect components of electrical circuits (108) from vibration, moisture and static discharges. The anti-solder mask (202) can be used as a thin gasket to prevent the ingress of potting compound between the modular component (300) and the PCB (110).

Abstract: The invention relates to a lead-free solder paste comprising a solder paste flux and solder alloy particles that are substantially lead-free wherein the solder paste flux comprises resin dissolved in a solvent and also includes undissolved resin particles less than 25 &mgr;m in size homogenously dispersed therein to provide improved solder alloy powder coalescence and substrate surface wetting while maintaining appropriate solder paste rheology for use in printed circuit board assembly processes.

Abstract: A method of forming solder connections on a circuitized substrate having connection pads is provided. A laser ablatable solder mask material, preferably an epoxy, is degassed and then dispensed as a liquid onto the substrate over the circuitization. The surface of the solder mask material as applied is leveled, and the solder mask material is then cured to form a solder mask. Openings are laser ablated in the solder mask material to reveal those connection pads which are to receive solder to form the solder connections. Liquid solder is dispensed under pressure in a confined space into the openings as blades move laterally on top of the solder mask to fill the openings in the solder mask. The solder material is then solidified to form domed solder bumps in the openings.

Abstract: Method of welding cladding to a surface of a metal component of a nuclear reactor at a region susceptible to stress corrosion cracking, in which the metal is welded to the surface of the component under conditions of low heat input to achieve reduced thermal sensitization at the edges of and within the newly clad region.

Abstract: A method for protecting tin oxide coated solder surfaces against further oxidation and a method for fluxless solder joining of such surfaces is provided.

Abstract: A method of brazing a metal work is disclosed, in which the work is heated to at least the softening temperature of resin and coated with a suspension constituted of a mixture of a flux and a binder, after which the work is brazed by being heated and dried. As a result, the binder (resin) attached to the surface of the work is softened and increases in stickiness. Even if foreign matter becomes attached to the work surface, therefore, the binder causes the flux to be firmly attached to (coupled with) the work surface together with the foreign matter. Thus, the flux can be securely coated (attached) on the work surface. The temperature of the work is not lower than the evaporation temperature of water. Even if oil becomes attached to the work surface, therefore, the water in the suspension is evaporated before it can be repelled by the oil, thus making it possible to prevent the flux from being repelled along with the water. In this way, the flux can be securely coated (attached) on the work surface.

Abstract: A method of forming a plurality of micro column interconnection structures on a semiconductor includes providing a semiconductor layer. A photoresist layer is formed on the semiconductor layer. A plurality of cavities are etched in the photoresist layer. The plurality of cavities extend through the photoresist layer to the semiconductor layer. Solder is deposited in the plurality of cavities, thereby forming a plurality of micro columns of solder.

Abstract: A method for brazing beryllium-aluminum alloy members to form a beryllium-aluminum alloy assembly and coating the beryllium-aluminum alloy assembly in which an aluminum-silicon based braze alloy is placed between the beryllium-aluminum members at the locations for forming braze joints. The aluminum-silicon based braze alloy is surrounded by a brazing flux comprising aluminum fluoride. The beryllium-aluminum alloy members and the aluminum-silicon based braze alloy are heated to form the beryllium-aluminum alloy assembly. Oxidized surfaces appearing on the beryllium-aluminum alloy members are removed. Thereupon, the beryllium-aluminum alloy assembly is coated by plasma deposition of alumina-titania powder.

Abstract: An improved soldering system which reduces the numbers of steps for paste supply and soldering in soldering lead provided parts and surface mounting parts onto a printed circuit board. A printed circuit board has through holes through which a lead of each lead provided part is to be inserted and lands for surface mounting parts. A printing mask is matched with the through holes and lands and a paste receiving plate having holes to which solder paste is to be supplied corresponding to each of the through holes is disposed. A printing roller is swept by forcibly rotating it so as to fill with solder paste, then a printing squeegee is swept following that printing roller so as to further fill with solder paste.

Abstract: To form a micromachine package, bond pads on a front surface of a controller chip are aligned with corresponding traces on a front surface of a micromachine chip. The bond pads are physically connected to the traces thus mounting the controller chip as a flip chip to the micromachine chip. A bead is formed around a periphery of the controller chip. The bead and the controller chip form an enclosure around a micromachine area in the front surface of the micromachine chip. This enclosure protects the micromachine area from the ambient environment.

Abstract: A pressing device including a platen for pressing a workpiece is provided, which has a pressing plate provided between the platen and the workpiece to press the workpiece instead of the platen when the platen is moved toward the workpiece, and a liquid layer formed between the pressing plate and the platen to transfer a force for pressing the workpiece with a required pressure to the pressing plate from the platen through the liquid layer. The platen is a heating platen heatble to a temperature sufficient to heat the workpiece to a temperature required for pressing, and the liquid layer is filled with heat transfer oil. The pressing plate is metal plate with a mirror finished surfaces.

Abstract: A method of forming a plurality of micro column interconnection structures on a semiconductor includes providing a semiconductor layer. A photoresist layer is formed on the semiconductor layer. A plurality of cavities are etched in the photoresist layer. The plurality of cavities extend through the photoresist layer to the semiconductor layer. Solder is deposited in the plurality of cavities, thereby forming a plurality of micro columns of solder.

Abstract: A metal oxide coating has a nanotextured surface defined by a plurality of capillary openings arranged in a pattern on the surface of the coating. Each of the capillary openings have a diameter defined by a previously present organic macromolecule. The metal oxide coating is formed by depositing a solution containing uniformly dispersed micelles composed of amphiphilic molecules on a metal, oxide, or plastic substrate. The micelles are self-arranging, in solution, as a result of mutually repulsive electrostatic forces on the surface of the micelles, and form a uniformly patterned organic template when the solution is deposited on the surface of the substrate. A metal oxide coating is then applied to the substrate, which forms a ceramic monolayer that is a negative image of the organic template. The organic template is then removed, thereby forming a metal oxide coating having a plurality of macromolecular-sized apertures formed therein.

Abstract: The present invention is a process for manufacturing an electronic circuit device by applying a solder material to electronic parts or electrodes on a printed circuit board; the process comprising the steps of removing an initial surface oxide film and an organic contaminant film from the surfaces of the solder material and electrode, covering the solder material and an area to which solder is to be applied which is comprised of the electrode, with a liquid vaporizing up after the bonding is completed in the step of heat-melting the solder material, to thereby prevent reoxidation of the joining area surface, and heat-melting the solder material, to carry out solder bonding without using any flux.

Abstract: An improved underfill adhesive encapsulant with fluxing activities containing an epoxy resin or a mixture of epoxy resin. An anhydride is used as the curing agent to harden the epoxy resin. A hydroxyl-containing fluxing precursor compound is added to the encapsulant composition to react with the anhydride curing agent to produce an active fluxing agent under typical reflow conditions. The use of a fluxing precursor gives improved reliability compared to conventional fluxing agents used in existing no-flow underfill encapsulants. A suitable catalyst such as imidazole, imidazole derivative or metal acetylacetonate is provided in the present encapsulant at concentrations that give good curing kinetics. A thermoplastic is optionally included to allow the cured encapsulant to be reworked.

Abstract: A method for forming a barrier to flow of brazing alloy on the surface or into internal cavities of a component to be treated by brazing. A quantity of stopoff slurry comprising alumina and a polyethylene oxide binder is applied to a surface of the component or into internal cavities of the component. The slurry is dried to set the binder and form a hardened stopoff material on the surface or in the internal cavities to form a barrier to flow of brazing material.