Abstract: The invention relates to an aluminium extrusion alloy comprising in weight percent: Mn 1.0-1.4, Cu 0.2-2.0, Mg 0.1-0.6, Si 0.15-1.0, Fe 0.8 max., Zn 0.25 max., Ti 0.15 max., Cr 0.35 max., Zr and/or V in total 0.25 max., others up to 0.05 each, total 0.15, balance aluminium, and with the proviso that (Cu+Mg)>0.7, and which aluminium extrusion alloy is particularly suitable for application in brazed assemblies, and the invention further relates to a method of its manufacture.

Abstract: A flux supply device comprises a liquid replenishing portion containing a liquid flux for replenishment, a liquid holding portion connected to the lower end of the liquid replenishing portion with a first electromagnetic valve provided therebetween, and a liquid supply portion connected to the lower end of the liquid holding portion with a second electromagnetic valve provided therebetween. The lower end of the liquid supply portion is located in a flux storage tank in which a mixed gas is generated. A gas blow-in pipe for supplying a combustible gas is also located in the flux storage tank. The first electromagnetic valve and the second electromagnetic valve are controlled in given timing so that one opens and closes and then the other opens and closes, alternately and repeatedly. This prevents the pressure variation in the flux storage tank from affecting the liquid replenishing portion and the surface level of the liquid flux in the flux storage tank is kept unchanged.

Abstract: An effective method for cleaning flux residues produced in process of fabricating semiconductor devices, and a method of fabricating the semiconductor devices including this cleaning method are provided. The flux cleaning method for cleaning the solder bump electrodes formed using a flux comprises the steps of: applying a pretreatment process including coating of the solder bump electrode with the flux and applying a heat treatment thereto, and carrying out the flux cleaning to clean the heat-treated flux.

Abstract: A method of pretreating a copper surface for protecting the surface from oxidation, by immersing the surface in a solution containing organic solderabilty preservatives, such as BenzoTriAzole, with the addition of a zinc salt. The method is particularly useful in the manufacturing of electronic Printed Circuit Boards for protecting the copper surfaces during the solder processes when the PCB undergoes high temperature. The addition of the zinc salts also gives the additional advantage of increasing the solderabilty properties of the copper surface (i.e. wettability and adhesion).

Abstract: A flux-application fixture for applying flux to die pads in a ball-grid-array assembly process is provided. The fixture comprises a solid plate having a lower surface and an upper surface and a plurality of flux pins formed in the upper surface of the solid plate. The flux pins are contiguous with the solid plate and are formed by removing material from the upper surface of the plate such that the remaining material not removed forms the plurality of flux pins. In a preferred application the material is removed by grinding and the flux plate is ground flat to tight tolerance before removing the material to form the flux pins.

Abstract: The present invention relates to a composition for preventing creeping of a flux for soldering, which is free from a problem from the viewpoint of the global environment or working environment. The present invention provides a composition for preventing creeping of a flux for soldering, consisting of a composition comprising a polymer containing polymer units of an unsaturated ester containing a polyfluoroalkyl group, a fluorine-type surfactant and an aqueous medium. Further, the present invention provides a method for soldering by means of the composition. Furthermore, the present invention provides an electronic part or printed board soldered by the method. Still further, the present invention provides an electric appliance employing such an electronic part or printed board.

Abstract: A flux which contains irreversibly dehydrated K2AlF5, for soldering light metal materials, in particular aluminum. The flux has the advantages of forming a very uniform flux coating on the workpiece or workpieces to be soldered and exhibiting outstanding flow of the solder. An appropriate soldering process, an aqueous flux suspension and preparation processes for the flux are also disclosed.

Abstract: A method for attaching a semiconductor die or flip chip to a substrate to form a printed circuit board. A dispensing apparatus is spaced away from a substrate so that the dispenser does not contact the substrate. Droplets of no-flow flux and underfill material are dispensed from the dispensing apparatus onto a substrate. A flip chip with an array of solder balls or bumps on its underside is push through the material until it contacts the substrate. The flip chip and the substrate are heated sufficiently to form mechanical and electrical connections therebetween. The method of the present invention can apply the no-flow flux and underfill material in a predetermined pattern. Furthermore, the predetermined pattern of droplets can be tailored to also include a desired topography. That is, the height of the no-flow flux and underfill material can vary relative to the substantially flat surface of the substrate.

Abstract: A soldering flux containing borneol, which is also referred to as bornyl alcohol. A method soldering using such a flux is also disclosed. Even minor proportions of borneol in the flux help reduce ionic residue from the flux after soldering. Larger proportions of borneol can give the flux tackiness for wave soldering operations. The flux preferably comprises borneol and an organic acid activator that volatilizes during soldering. The flux is applied as a solution of borneol and the organic acid activator in a solvent that substantially evaporates before soldering without leaving any measurable solvent residue.

Abstract: A method of avoiding generation of waste water while brazing components made of aluminium or an aluminium alloy using a flux, especially a flux composed of an aqueous suspension of potassium fluoroaluminate. Since used suspension is replaced with fresh suspension after a given period of time and the apparatus regularly have to be cleaned, waste water is produced which contains flux, e.g. potassium fluoroaluminate. In the past, such waste water has been discharged into the environment. It has now been discovered that such waste water can be recycled to the brazing process after separation of the flux. In this manner, the production of waste water can be largely avoided. Since surfactants are frequently used, and these are likewise recirculated, a corresponding saving in terms of surfactant is possible. Furthermore, the environment is protected correspondingly.

Abstract: The invention relates to a method for drying fluxing of a metallic surface before soldering or tinning using an alloy, according to which the surface to be fluxed is treated, at a pressure close to atmospheric pressure, with a gaseous treatment atmosphere comprising excited or unstable species and being substantially free of electrically charged species, which is obtained from a primary gas mixture and, optionally, an adjacent gas mixture, the primary gas mixture being obtained at the gas outlet of at least one apparatus for forming excited or unstable gas species, in which an initial gas mixture comprising an inert gas and/or a reducing gas and/or an oxidizing gas has been converted, the adjacent gas mixture not having passed through the apparatus.

Abstract: A flux formulation without a surfactant is available for use in the assembly of electronic circuit boards as a no-clean formulation. The formulation includes a flux solution having a fluxing agent consisting essentially of one or more weak organic acids and a solvent consisting essentially of water. The flux solution serves to transport the fluxing agent before deposition thereof upon a soldering site for reliability improvement engendered by a lack of hygroscopic residue and for avoidance of environmental degradation engendered by a lack of volatile organic chemicals (VOC's). The method includes the steps of heating the flux solution and dispersing it as a fine spray.

Abstract: A method for preparing a Ni base superalloy inner wall surface of a body open end, such as an end of a turbomachinery blade, and an end plate, such as a blade tip cap, for brazing together at a rim of the end plate includes electrochemically removing oxides from the inner wall surface. The end plate is prepared, at least at its rim, by first removing surface and subsurface oxides, for example by mechanical abrading or a combination of such abrading and acid cleaning. Then at least the rim is electroplated with Ni which is heated to diffuse the Ni into the rim substrate. This provides an improved combination of surfaces for brazing, for example with a Ni base brazing alloy. After brazing the rim to the inner wall, there is provided an article with an improved relatively low oxide brazed joint, including less than about 20 volume % oxides, and a plate rim of substantially Ni along with elements diffused from the brazing alloy and the rim.

Abstract: A scale formation-inhibitory agent used in a welding treatment comprises a polymer selected from the group consisting of polymers having oxygen atoms in the main chain and polymers capable of being thermally depolymerized. The scale formation-inhibitory agent can inhibit the formation of scale on the surface of a metal part to be welded during a welding treatment.

Abstract: The forming oil degreasing step and flux coating step are reversed as part of a basic fluxed heat exchanger brazing process. This allows the fluxed parts to be thermally degreased concurrently with the braze oven workpiece preheat process, eliminating a separate degrease step and apparatus entirely. Surprisingly, and contrary to all teaching as to electrostatic dry power coating, powdered flux was found to electrostatically bond to an oily surface as well as, or even better than, an oil free surface.

Abstract: The invention relates to a method for dry cleaning or dry fluxing metallic surfaces before, during, or after a reflow soldering operation. The metallic surfaces that are dry cleaned or dry fluxed include (1) the metallic substrate on which an at least partially metallic, electronic component is to be mounted, (2) the solder paste, and (3) the metallic portions of the electronic component. The method comprises treating the metallic surface with a gaseous treatment atmosphere comprising unstable or excited gaseous species, and is substantially free of electrically charged species.

Abstract: A method and system for introducing flux onto at least one surface of a solder pump achieve their objects as follows. A solder pump nozzle is submerged into a flux reservoir. In response to such submersion, the flux in the reservoir is actively introduced into the solder pump nozzle. In one embodiment, the active introduction is achieved by creating a negative pressure in a solder pump nozzle such that flux fills a vacated volume. The created negative pressure is produced by moving a solder column, contained within the solder pump nozzle, under the influence of an applied electric current and an applied magnetic field.

Abstract: A tool for soldering pin-in-hole electronic circuit components includes a tool plate with a set of via holes corresponding to the holes of a circuit board on which a circuit component is soldered. The board is aligned with the tool plate and hot gas is supplied through the set of plate vias to reflow solder in the board holes. The tool is particularly suitable for use in removing and replacing pinned circuit components. Use of particular gases (e.g., nitrogen) allows soldering to be carried out without the use of flux. Advantages of the tool are that it prevents burning the circuit board and/or unintentionally reflowing other circuit components mounted on the board (by directing hot gas only substantially onto the circuit board's solder-containing holes).

Abstract: Copper-containing surfaces of substrates such as laminated electronic circuit boards are protected by organometallic coatings comprising organic compounds selected from the group consisting of benzimidazoles, alkylimidazoles, benzotriazozles and alkyltriazoles, substituted or unsubstituted, and metal particles of solder-wettable metals or metal solders. The metal particles can be thermally formed in situ from metallic compounds such as noble metal acetates, acetylacetonates and carbonates.

Abstract: A flux formulation without a surfactant is used in the assembly of electronic circuit boards as a no-clean formulation. The formulation includes a flux solution having a fluxing agent consisting essentially of one or more weak organic acids and a solvent consisting essentially of water. The flux solution serves to transport the fluxing agent before deposition thereof upon a soldering site for reliability improvement engendered by a lack of hygroscopic residue and for avoidance of environmental degradation engendered by a lack of volatile organic chemicals (VOC's). The method comprises the step of heating the flux solution and dispersing it as a fine spray.

Abstract: A method for soldering is disclosed wherein parts to be soldered are passed sequentially into and out of a flux and a solder bath. The flux cleans the parts of surface debris, such as oxides, before the parts are immersed in the solder.

Abstract: A flux composition for use together with solder preforms, which comprises rosin, N-unsubstituted or N-substituted 2-pyrrolidone, and optionally a high boiling point ester solvent with a content of N-unsubstituted or N-substituted 2-pyrrolidone being 3-50% by weight and a content of the ester solvent being not greater than 30% by weight.

Abstract: A method for producing pore-free cast-on-strap joints for lead-acid batteries including the steps of cleaning a plurality of positive and negative plate lugs by a combined action of flux and ultrasonic vibration, water rinsing the plate lugs under ultrasonic vibration, and drying the plate lugs by gas blasting. The gas blasting occurs prior to the formation of the cast-on-strap joint. The cast-on-strap joint is formed by introducing the plate lugs into a molten lead-based strap alloy contained in a strap mold and solidifying the molten strap alloy in the strap mold.

Abstract: In soldering together two members such as electronic circuit devices, after an oxide or contaminated layer has been removed from the surface of a solder material or bonding pad, for example, the members are aligned in an oxidizing atmosphere. Then the solder material is heated in a nonoxidizing atmosphere to melt the solder and bond the members. Cleaning of the solder material or bonding pad is performed by sputter-cleaning, laser cleaning, mechanical polishing, or cutting.

Abstract: Multiple I/O pads are arranged in a pattern on a surface of an integrated circuit package, and an obstruction in the package prevents a planer solder flux mask from lying flat on the surface around the I/O pads. Such an obstruction can, for example, be a lid in the package which projects above the I/O pads, or it can be an encapsulant which covers a chip in the package and projects above the I/O pads. Despite the presence of the obstruction, solder flux is dispensed on the I/O pads of the integrated circuit package by the steps of --a) providing a pin block that has a base from which multiple pins project, and the ends of the pins match the pattern of the I/O pads; b) coating the ends of the pins with a solder flux; and, c) transferring a portion of the solder flux from the ends of the pins to the I/O pads by temporarily touching the coated ends of the pins against the I/O pads.

Abstract: A method for depositing a tacking agent (18) onto a circuit-carrying substrate (e.g., a printed circuit board) (22) such that a regulated volume is simultaneously deposited at multiple substrate sites (24). A first input pressure, P1, introduced through a bladder inlet (12), is supplied to a compliant bladder (14) which is in contact with a plurality of transfer pins (16). The compliant bladder imparts a substantially equal force to each of the transfer pins. The pins are then dipped into a thin film of tacking agent and removed. Subsequently, the first input pressure, P1, is adjusted to a second input pressure, P2, sufficient to force the pins to a uniform maximum extension. Finally, the second input pressure, P2, is adjusted to a third input pressure, P3, which imparts a predetermined uniform force on each of the pins, and the pins are brought in contact with the printed circuit substrate deposition sites.

Abstract: A direct chip attachment process and apparatus for aluminum wirebonding on copper circuitization are provided. After at least one integrated circuit chip is attached to a carrier, an aqueous cleaning solution containing citric and oxalic acid based additives is applied to the carrier and attached integrated circuit chip. Then a deionized water rinse is applied to the carrier and attached integrated circuit chip, followed drying for a set time period. Next wirebonding on copper circuitization carried by the carrier is performed.

Abstract: Rectangular preforms are vacuum picked and placed in each cavity of a first holder, and a measured amount of no-clean flux liquid is dispensed onto each preform, then a second holder is placed in an inverted position on top of the first holder and the holders are flipped so that the dry side of the preform is exposed and then a measured amount of no-clean solder is dispensed on the dry side of the preform. A robot arm with a rubber tipped vacuum probe picks up the preforms without damage or contamination and places them on a circuit board, grippers of the robot arm pick up and position a component on an induction coil to heat it up sufficient for reflow soldering, and then move the component onto the preform on the circuit board for reflow soldering. The circuit board can be used without cleaning with solvents or CFC's, thus reducing process steps and reducing environmental hazards.

Abstract: A prefluxed, flux retaining aluminum-based component is provided comprising a solidified coating layer having flux particles embedded into the coating layer. A method for producing such components comprises steps of applying a molten metallic coating to an aluminum-based component, maintaining the coating in a molten state, driving flux particles against the coating, and cooling the component to solidify the coating and thereby fix the particles firmly in the solidified coating.

Abstract: A hot air circulation apparatus and method for wave soldering machines which heats air from a high-pressure air source and directs it at the flux applied to a printed circuit board. The heated and pressurized air also circulates air within the wave soldering machine to force the moisture out. A plurality of hot air knives are mounted adjacent heaters within the wave soldering machine and are coupled to the pressurized air source. The hot air knives include a hollow metal cylindrical member which conducts heat from the heater, and contain a plurality of orifices which increase the pressure of the air and direct the air at the flux.

Abstract: Metallic alloy parts which contain easily oxidizable metallic elements, are welded without solder by applying a non-deliquescent flux thereto at a negligible amount and subjecting them to a high temperature under an inert and non-explosive atmosphere.

Abstract: The present invention relates to a method for mounting electronic devices on a substrate by using soldering with flux which contains materials capable of ion-exchanging or ion-catching so as to catch impurity ions which seep from a solder portions, and thereby it is not necessary to have a fusing step and a cleaning step in an plating process of the method.

Abstract: A flux-free method for bonding a member which is at least partially metallic to another member is provided including preserving the at least partially metallic member in a container having a low gas permeability, together with a packet containing a rust-proof composition; and bonding the at least partially metallic member with the other member by using a filler material.

Abstract: A method and apparatus for applying flux to a series of metallization contacts or plated contact pad a substrate exposed by an apertured solder mask, employs a compressible transfer pad. A central flux pick-up area is formed on the transfer pad bottom surface. The bottom surface may be spherical and may include a cylindrical post onto which a predetermined amount of flux is transferred, such as by dipping the pick-up area into a reservoir of semi-liquid paste flux. The transfer pad is then positioned over and compressed on the solder mask such that the picked up flux on the flux pick-up area of the transfer pad is pressure forced by compression of the transfer pad through apertures in the solder mask directly and successively into all the series of depressions formed on the substrate until all the depressions are substantially filled with flux.

Abstract: A non-toxic, non-corrosive liquid soldering flux consists essentially of a solution of citric acid in water. This unique flux produces solder joints of high metallic luster and excellent quality. Disposal presents no health hazards, and clean-up of flux residues is accomplished using only water.

Abstract: Solder particles 220 are deposited onto metallized contacts of a direct chip attach (DCA) site located on a substrate 301. The contacts 302 are coated with a layer of flux 303. A pick up head 211 is positioned in a reservoir 201 of solder particles 220 and particles are attracted to the apertures in the end 213 of the head. The apertures have an arrangement corresponding to the footprint of the metallized contacts on the substrate. The head 211 is positioned adjacent the substrate 301 and the particles 220 released. The particles 220 stick to the flux 303 coated on the contacts 302. The particles are reflowed, leveled and again coated with flux. An integrated circuit chip is then placed on the leveled reliefs 501 and the reliefs reflowed again to attach the chip onto the contacts 302.

Abstract: An integrated circuit (70) is soldered to a printed circuit board (200) by first depositing flux (116) on bumps (75) of the integrated circuit. Solder (214) is deposited upon the bumps (75), and the integrated circuits is (70) placed in contact with pads (210) on the printed circuit board (200). After reflow, a solder joint (230) electrically and mechanically attaches the integrated circuit (70) to the printed circuit board (200).Alternatively, the solder tipped (214) bumps (75) may be placed in contact with a non-adhering flat plane (300) such as glass during the heating process. After reflow, each bump has a flat portion (350), and the flat portions of all the bumps form a plane (400) which further facilitates attaching the integrated circuit (70) to the printed circuit board (200).

Abstract: A method of preparing a component for automated placement is provided. The method includes disposing tacking medium on a substantially transparent member (210); engaging the tacking medium with the component (230); and imaging the component through the substantially transparent member (240).

Abstract: A joint and a laminate including a nickel-titanium alloy such as Nitinol and a method for preparing the surface of a nickel-titanium alloy member for bonding solder material and, electively, another similar or dissimilar member thereto. The method includes applying a halogen containing flux to the titanium oxide coated surface of a nickel-titanium alloy member and heating the flux to its activation temperature. The flux removes and suspends the titanium oxide therein and deposits a metal from the halogen containing flux on the oxidation free surface. The activated flux also coats the member surface for protection from further oxidation. A bonding material such as a tin-silver solder is flowed onto the tinned surface to displace the activated flux. Electively, another member is applied to the molten solder to form a joint between the two members. The residual flux is cleaned from the joint to prevent further deterioration of the base metal.

Abstract: The solder bonding is conducted by applying a postflux, which contains halogen compounds in the ratio of 0.2% or less as the amount of halogen, over a metal surface, which is the portion to be bonded by solder, of a member including metal accommodated in a gas-impermeable container in a hermetically sealed manner together with a rust-proof agent packet. The method of the present invention prevents, in an extremely simple way and at a low cost, the oxidation of the metal surface by retaining the member including the metal under a reductive atmosphere in which no oxygen, moisture or corrosive substances actually exist, and in which reductive gas co-exists with the material including the metal member, and the use of the flux containing a small amount of halogen easily enables good bonding properties of the solder. Accordingly, it is unnecessary to remove the flux by organic halogen based solvents after the solder bonding, the cleaning steps may be simplified and cost reduction may be promoted.

Abstract: A joint and a laminate including a nickel-titanium alloy such as nitinol and a method for preparing the surface of a nickel-titanium alloy member for bonding solder material and, electively, another similar or dissimilar member thereto. The method includes applying an aluminum paste flux to the titanium oxide coated surface of a nickel-titanium alloy member and heating the flux to its activation temperature. The flux removes and suspends the titanium oxide therein along with leaching titanium from the base alloy member surface to form a nickel-rich interface surface. The activated flux also coats the nickel-rich interface layer for protection from further oxidation. A bonding material such as a tin-silver solder is flowed onto the nickel-rich interface surface to displace the activated flux. Electively, another member is applied to the molten solder to form a joint between the two members. The residual flux is cleaned from the joint to prevent further deterioration of the base metal.

Abstract: A low temperature-wetting solder paste for forming a tin-base solder connection comprises a mixture of compositionally distinct first and second solder powders. The first solder is formed predominantly of tin, preferably at least 90 weight percent. The second powder is formed of a tin alloy containing indium or bismuth and having a melting temperature less than the first powder. During soldering, the second powder melts during the early stages of the heating cycle to initiate wetting of the faying surfaces and promote dissolution of the first powder, thereby reducing the time and temperature required to form the solder connection.

Abstract: A non-toxic, non-corrosive foaming soldering flux (14) comprises citric acid and water, together with at least one foaming agent. The foam is fast-breaking, dissipating almost immediately. Such a fast-breaking foam is novel in an aqueous-based flux. The unique flux of the invention produces solder joints of high metallic luster and excellent quality. Disposal presents no health hazads, and clean-up of flux residues is accomplished using only water and, optionally, a surfactant.

Abstract: Water soluble soldering preflux compositions are shown which include gum arabic, modified polysaccharides and other natural resins as a carrier, an oxidation inhibitor and water. The compositions are useful in the assembly of precisely aligned electrical components during multiple step, electronic card assembly techniques. Use of the preflux compositions according to the method of the invention permits a flexible, site-specific method for joining electronic components to a printed circuit board with a fewer number of steps.

Abstract: A volatile flux coating solution which, when dry, provides durable protective film coating containing residual flux, and a fluxing-soldering process utilizing such a solution. The coating solution is applied to a cleaned metal surface to be later joined and soldered to another metal surface, thereby obviating the need for recleaning and refluxing at the time of joining and soldering. Where two objects prepared according to this invention are joined, no additional cleaning or fluxing is required, thus saving significant time and labor at the work site. However, an object prepared according to the present invention may nevertheless be joined to an unprepared object at the work site if the unprepared object is prepared by conventional techniques, thereby allowing the prepared object to be joined with either prepared or unprepared objects. The soldering process is completed by soldering the two objects together according to conventional techniques.

Abstract: A non-toxic, non-corrosive liquid soldering flux is provided, comprising an organic acid, such as citric acid, and a non-toxic carrier, such as water. This unique flux produces solder joints of high mettalic luster and excellent quality. Disposal presents no health hazards, and clean-up of flux residues is accomplished using only water.

Abstract: A dispenser (100) for solder flux includes a first solder flux reservoir (110) with a dispensing tip (118) at one end thereof for dispensing solder flux (112) in response to a frictional pressure applied to the tip. A second solder flux reservoir (102) is also included having a dispensing channel (106) for dispensing solder flux (104) responsive to a pressure applied to the flux (104) within the second solder flux reservoir (102).

Abstract: A water soluble solder paste, which does not adversely impact the surface insulation resistance (SIR) of a circuit board, is comprised of powdered solder, a water soluble flux (containing an activator within a water soluble vehicle), a hydrophobic surfactant preferentially absorbed over the water soluble vehicle, and a solvent within which the surfactant and flux are dissolved. The hydrophobic surfactant is chosen to be preferentially absorbed by the circuit board surface over the water soluble flux vehicle to prevent the vehicle, which is hydrophilic from becoming trapped in the board surface, thereby adversely affecting the board SIR.

Abstract: A process for soldering a substrate surface which allows low ionic contamination without a cleaning operation which comprises (a) applying a stannous fluoride or eutectic mixture thereof to the substrate surface and (b) applying solder to the flux applied in (a). The stannous fluoride which is relatively inactive below its melting temperature can be applied to the substrate surface and the so treated substrate held for an extended period of time prior to soldering without any harmful effect on the substrate. The process is useful in electronic assembly that would include attachment of components to circuit boards, tinning of circuit boards, pretinning of component leads, connectors etc.

Abstract: A water-soluble soldering flux which does not adversely impact the surface insulation resistance of a circuit board is comprised of a water-soluble vehicle, an activator and a hydrophobic surfactant preferentially adsorbed at the board surface. At soldering temperatures, the activator reacts to clean metallized areas on a circuit board and promote solder wetting. The hydrophobic surfactant, which is preferentially adsorbed at the board surface, acts to block the diffusion of hydrophilic vehicle molecules into the board which would otherwise degrade the board's surface insulation resistance.