Abstract: A flip chip bonding method including steps of applying a pressure and a heat and applying an ultrasonic wave in a plurality of directions or along a circular locus for connecting solder bumps, which are formed on one or both of a connecting pad of a semiconductor element or a connecting pad of a wiring board, whereby flip chip bonding is performed without using flux, a drop of yield and deterioration of reliability are improved.

Abstract: A microelectronic connection component is provided with leads having a surface wettable by a bonding material such as a solder at the tips of the leads which are intended to be bonded with microelectronic devices. The leads have non-wettable surfaces bounding the wettable surfaces. During bonding, the non-wettable surfaces confine liquid bonding material such as liquid solder and prevent the liquid bonding material from spreading along the leads.

Abstract: A brazing sheet product and a method of manufacturing a brazing sheet product in which a layer comprising nickel is plated onto a surface of a clad layer made of an aluminium-silicon alloy containing silicon in the range of 2 to 18 weight %, wherein the surface is pre-treated by application of a bonding layer comprising zinc or tin. The application of the bonding layer may be by a zincate or a stannate treatment. The use of lead to promote wetting during brazing can be reduced or avoided, or other elements such as bismuth can be used.

Abstract: The invention relates to a gas distribution system which can be connected to a gas supply, the purpose of said gas distribution system being to admit and distribute a non-oxidizing gas in a shroud (17, 20, 21, 23) covering at least one solder container (22). Printed circuit modules (12) are transported through said shroud and while they are being transported, are brought into contact with a wave of solder (24). The gas distribution system has at least one gas distributor situated above and at least one gas distributor (19, 31) situated below the printed circuit modules (12) in order to produce a protective gas atmosphere with low residual oxygen values. Both gas distributors are provided with flow elements (48, 49, 51 to 56, 59; 35, 37, 44, 45). Said flow elements produce a displacement gas blanket which is distributed homogeneously over the discharge surfaces (59, 44, 45) directed towards the solder container.

Abstract: A heat exchanger and method of assembly for an automotive vehicle includes at least one tube having an internal surface and an external surface, and a composition cladding having at least magnesium applied to the internal surface and external surface of the tube.

Abstract: There is provided a flow soldering process for mounting an electronic component onto a board by means of a lead-free solder material, wherein the molten solder material is supplied and attached to a predetermined portion of the board in a solder material supplying zone, and thereafter the board is cooled by a cooling unit in a cooling zone such that the solder material adhering to the board is rapidly cooled to solidify.

Abstract: By utilizing a roll bonding process and appropriately forming steps, a load bearing structure is created which is capable of handling and appropriately transferring loads. One preferred method includes the combination of roll bonding and hydroforming to efficiently create structural components. While various product configurations are possible, one version includes a waffle-type structure produced by appropriate roll bonding of material sheets. This waffle-type structure can also undergo additional forming steps to create several structural components capable of handling and carrying loads in a very efficient and effective manner. More significantly, this process enables the use of structural aluminum for load bearing components which are efficiently and cost effective when manufactured.

Abstract: An apparatus and method for recovering solder from dross present on the surface of a molten solder where it is exposed to atmospheric air. The apparatus includes a solder reservoir for holding a pool of molten solder, and a solder nozzle disposed in the solder reservoir and adapted to direct a solder wave against a printed circuit board to be soldered. The solder nozzle includes opposite side troughs inclined downwardly toward one side of the solder reservoir to direct dross toward a dross zone. A semicircular hood extends across the solder reservoir and located above the dross zone. A screw extends across the solder reservoir and covered by the hood. The screw is activated to agitate the dross so as to remove oxides and recover solder from the dross.

Abstract: A soldering apparatus has a solder container and a casing to accommodate a protective-gas atmosphere for soldering printed circuit boards. During transport of the circuit boards through a casing the circuit boards are brought into contact with a solder wave in the container. The casing has an inlet for printed circuit board on an inlet side and an outlet on its outlet side. In addition, the casing has a supply of non-oxidizing gas and an arrangement for admitting gas into the casing. The casing is designed as a modular construction kit having subassemblies and/or constructional elements which comprise an input tunnel, an entry tunnel, at least two covering elements, an outlet tunnel and a detachable connection on the solder container and/or the sub-assemblies and/or constructional elements to connect the sub-assemblies and/or constructional elements and the solder container.

Abstract: A method of attaching a lid with at least a metallic surface thereon to a substrate to enclose a surface acoustic wave electronic circuit using a fluxless solder preform having an undesired oxide surface and associated with the metallic surface on the lid and in superimposed and abutting relationship with a gold seal ring surrounding the electronic circuit to form a unit that is heated in a furnace having a hydrogen atmosphere such that the hydrogen removes any undesired oxide surfaces from the solder preform and the metallic surface on the lid by combining with the oxygen therein to form moisture so as to remove any oxide surfaces from the solder preform and the lid metallic surface and enable a complete bonding of the fluxless solder preform with the gold seal ring and the lid metallic surface thereby forming a hermetically sealed package.

Abstract: A rod material made of Ti alloy has a larger diameter portion at the end, which is joined with the end of material made of Ti—Al intermetallic compound, by friction welding, to form a poppet valve for an internal combustion engine. Instead of providing such larger diameter portion, the end of the material made of Ti—Al intermetallic compound may be heated to facilitate joining.

Abstract: Stainless steels are welded using a shielding gas including 88 to 98.9 mole % Ar, 1 to 10 mole % H2, and 0.1 to 2.0 mole % CO2. The shielding gas permits low sulfur, high chromium, austenitic stainless steel pipes to be joined with welds having sufficient penetration, strength, corrosion resistance and durability for practical use.

Abstract: The invention relates to a machine for wave soldering or tinning comprising

Abstract: An improved method of manufacturing a piezoelectric element and an improved piezoelectric element are provided. The improved method comprises the steps of causing a gas discharge in a predetermined discharge gas at approximately atmospheric pressure and generating an excited active species of the discharge gas as a result of the gas discharge. Then, at least one of a connecting surface of an electrode formed of a piezoelectric piece on a piezoelectric resonator and a connecting portion of a lead terminal are exposed to the excited active species, whereby the exposed connecting portions are surface treated. Finally, the electrode and the lead terminal are connected together, and at least the electrode and the lead terminal are sealed in a case. The improved piezoelectric element is formed by this process and uses less solder and is more stable than prior art piezoelectric elements.

Abstract: The invention relates to a method and apparatus to use nitrogen, or any other inert gas, or a reducing gas as a process gas to reflow and planarize solder paste in a single heating step. The inert gas may also be used to cool the solder paste after reflowing. According to one method soldered paste is printed onto the printed circuit board with conventional methods employing a mask or stencil. A mesh, die, or mold element having a plurality of openings therein is lowered onto the soldered paste and the printed circuit board is reflowed and planarized in a single heating step. Once the paste is applied, the parts are reflowed and planarized in a single, brief, thermal excursion. The heated mesh is lowered into the solder paste causing the paste to wick through the mesh forming a meniscus. A hot gas knife is arranged to plane the meniscus of the solder paste off of the mesh. An inert, nitrogen, or reducing gas is diffused through the knife to prevent oxidation.

Abstract: A brazing sheet product having a core sheet (1) made of an aluminium alloy, having one or both of the surfaces of the core sheet clad with an aluminium clad layer (2), and a layer (3) comprising nickel on the outersurface of one or both the aluminium clad layer or layers (2). There is a layer (4) comprising zinc or tin as a bonding layer between the outersurface of the aluminium clad layer or layers (2) and the layer (3) comprising nickel. The aluminium clad alloy layer comprises, in weight percent: Si 2 to 18, Mg up to 8.0, Zn up to 5.0, Cu up to 5.0, Mn up to 0.30, In up to 0.30, Fe up to 0.80, Sr up to 0.20, at least one element selected from the group consisting of: Bi 0.01 to 1.0, Pb 0.01 to 1.0, Li 0.01 to 1.0, Sb 0.01 to 1.0, impurities each up to 0.05, total up to 0.20; and balance aluminium.

Abstract: A method for breaking off solder bridges between pins of a through-hole component on a printed circuit board, comprises the following steps: (1) providing a soldering apparatus, the apparatus having an opening corresponding to the through-hole component, the opening defining an opening wall surface, providing a slit at a predetermined position of the opening wall surface; and (2) blowing a gas of a predetermined temperature and a predetermined pressure at a predetermined time to the position of the solder bridges through the slit for removing the solder bridges from the through-hole component.

Abstract: A wave soldering apparatus includes a solder reservoir adapted to contain molten solder, and a solder nozzle disposed in the solder reservoir and extending up above the molten solder. The nozzle provides a substantially turbulent free solder wave under a printed circuit board while the board is moved in a predetermined path. A tray is pivotably mounted to the nozzle and angularly moved to vary the flow rate of the molten solder. A shroud is mounted adjacent to and associated with the tray to define a contained space into which an inert gas is supplied to provide an inert gas atmosphere. The shroud includes a canopy extending over a portion of the tray. The canopy extends substantially parallel to the predetermined path and is adjustably positioned in response to angular position of the tray to ensure that the board exits from the solder wave within the inert gas atmosphere.

Abstract: First and second sub-parts are brought into contact with each other so as to form an unwelded hollow structure defining an internal volume. The internal volume of the hollow structure is inerted by introducing an inerting gas mixture into the hollow structure, the inerting gas mixture comprising from 93% to 99.8% nitrogen and from 0.2% to 7% oxygen and being produced by air permeation by means of one or more membrane modules. The first and second sub-parts are arc welded together so as to form a welded hollow structure.

Abstract: A soldering machine using lead-free solders is provided which can uniformly heat a printed circuit board and electronic parts to be mounted thereon, and which can solder the electronic parts without thermally damaging them. A porous member having a number of holes formed therein is disposed between a blower fan and a heater for making uniform the pressure of a fluid. A radiation plate is disposed between the heater and a heating target for blowing the fluid having been heated by the heater to the heating target in the form of a turbulent flow. The heated fluid is blown to the heating target for heating the same, whereby solder is melted.

Abstract: The process for manufacturing an electronic circuit includes disposing an electronic device on a circuit substrate and hot melting a solder formed on the electronic device or the circuit substrate to bond the electronic device and the circuit substrate. The process includes the steps of feeding a liquid onto lands on the circuit substrate, aligning and mounting the electronic device on the lands, placing the circuit substrate in a treating vessel and heating the circuit substrate. The heating step includes controlling a pressure of an atmosphere in the treating vessel, hot-melting the solder to prevent at least a portion of the liquid from evaporating until the electronic device and the circuit substrate are bonded and to permit the liquid to evaporate after the electronic device and the circuit substrate are bonded.

Abstract: A method and apparatus for solid bonding without using a bonding agent are provided. A surface of metal, glass, or other bond members 16a and 16b is fluorinated by exposure to a mixture of HF gas from a HF gas supply unit 24 and water vapor from a vapor generator 26 in a fluorination process section 12. The bond members 16a and 16b are then placed in contact at the fluorinated surface on table 36 in bonding process section 14. Argon is then introduced to bonding chamber 34. Pressure is then applied to the first bond member 16a and second bond member 16b by a cylinder 46, and heated to below the melting point by a heater 48, to bond the first and second bond members together.

Abstract: The present invention relates to an apparatus and a method for inerting a wave soldering installation having a solder bath (19) and a conveying system for producing one or more solder waves (14, 15), in particular for soldering electric printed circuit boards, having an immersion box (1) which is closed on all sides, shaped like a frame, can be immersed in the solder bath (19) and which has porous pipes (2, 3, 4) to distribute nitrogen, said pipes being arranged inside the immersion box in cage-like housings (5, 6, 7) with outlet openings (8, 9, 10), the cage-like housings (5, 6, 7) being designed such that the porous pipes (2, 3, 4) are arranged therein in such a way that the porous pipes (2, 3, 4) are essentially not struck by solder splashes produced during the operation of the wave soldering installation.

Abstract: A process for promoting fluxless soldering of a mass of bulk solder having a bulk ratio of a first metal to a second metal, such as lead-enriched solder that has significantly more lead than tin. The process comprises exposing the bulk solder to energized ions of a sputtering gas in the presence of a halogen, such as fluorine, and forming a surface layer having a desired surface layer ratio of the first to the second metal that is less than the bulk ratio, the surface layer further comprising an uppermost surface film containing the fluorine or other halogen. After the solder exposure and surface-layer formation, the process may further comprise electrically joining the solder to a surface without using externally-applied flux. This process enables the joining step to be performed at less than 300° C., at approximately 180° C.

Abstract: The invention relates to a protective gas for TIG welding of metals, especially high alloy or low alloy steel, whose thermal conductivity is lower than that of aluminium. The inventive gas consists of argon, helium and hydrogen and enables significant improvements to be made in electric arc stability, welding speed, oxidation of weld surface and adjacent area, flow-on performance and weld appearance.

Abstract: Apparatus for inerting a wave soldering installation having a solder bath and a conveying system for producing one or more solder waves, in particular for soldering electric printed circuit boards, having an immersion box which is closed on all sides, shaped like a frame, can be immersed in the solder bath and which has porous pipes to distribute nitrogen, the pipes being arranged inside the immersion box in cage-like housings with outlet openings, the cage-like housings being designed such that the porous pipes are arranged therein in such a way that the porous pipes essentially cannot be struck by solder splashes produced during the operation of the wave soldering installation.

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: In method for soldering metal microstructured plates, stacks of plates and solder layers are prepared by placing the solder layers between each adjacent plate. The thickness of the solder layers range from 3 to 25 &mgr;m. The stack is then soldered by heating it in a vacuum or an inert atmosphere.

Abstract: A method for providing fluxless soldering without oxide formation includes mounting a component on a pedestal of a base. A housing is also mounted on the base, the housing and the base together define a closed cavity containing the component. An inert gas is introduced into the cavity to create an inert gas-rich environment. Thereafter, the cavity is heated sufficiently to reflow solder provided between the component and the housing, to join the component to the housing without the formation of additional oxides on the solder joint.

Abstract: The invention relates to a friction welding process for mounting blades of a blade carrier (1) of a flow machine as well as a shielding gas shower for supplying gas to welding surfaces. To achieve this, a plurality of longitudinally extending welding surfaces (5a) are provided on the circumference of the blade carrier (1), are oriented at a blade angle &bgr; relative to the rotation axis (R) of the blade carrier (1), and are respectively welded together with a welding surface (5b) of a blade (2). The welding temperature necessary for joining the bodies (blade carrier (1), blade (2)) is achieved by pressing together the welding surfaces (5a,b) and simultaneous oscillating relative motion (P) of the bodies (1, 2) in the welding plane (E), whereby a shielding gas (S) flows around the welding surfaces (5a,b) during the relative motion (P). The shielding gas flow S follows the contour of the blade carrier and the blade and thus serves to provide a closed shielding gas curtain for protecting the welding surface.

Abstract: An apparatus for performing fluxless soldering includes an enclosure having a gas inlet through which an inert gas is introduced to create an inert gas-rich environment. Components are placed in the enclosure via an access port which also functions as a vent for allowing purge gases to vent from the enclosure. In one embodiment, a heating stage is provided in the enclosure which provides sufficient heat to reflow solder provided between two or more components. The inert gas is constantly flowing, or purging the enclosure in order to displace oxygen that would initially be present in the system. The presence of inert gas exclusive of other materials provides an oxygen-free environment, i.e., the inert gases provide a “shield” or environment around the parts to be soldered to inhibit the formation of additional oxides during soldering.

Abstract: An apparatus for performing fluxless soldering includes an enclosure having a gas inlet through which an inert gas is introduced to create an inert gas-rich environment. Components are placed in the enclosure via an access port which also functions as a vent for allowing purge gases to vent from the enclosure. In one embodiment, a heating stage is provided in the enclosure which provides sufficient heat to reflow solder provided between two or more components. The inert gas is constantly flowing, or purging the enclosure in order to displace oxygen that would initially be present in the system. The presence of inert gas exclusive of other materials provides an oxygen-free environment, i.e., the inert gases provide a “shield” or environment around the parts to be soldered to inhibit the formation of additional oxides during soldering.

Abstract: Disclosed is a method of preventing a gold plate connector of a printed circuit board (PCB) from being contaminated during a soldering process. The disclosed method prevents the gold plate connector coupled with the printed circuit board from being contaminated during wave soldering of the printed circuit board after spreading flux over the printed circuit board on which electronic components are mounted, and the method includes the steps of: forming a strip mask in a form of a membrane by solidifying a masking solution after spreading the masking solution capable of being solidified over the gold plate connector of the printed circuit board, performing the spreading of the masking solution before the spreading of the flux; and removing the strip mask from the gold plate connector after performing the wave soldering. As a result, it is not necessary to perform a washing operation of the gold plate connector. The washing operation can be troublesome, time-consuming, and inconvenient.

Abstract: Minor additions of calcium (Ca) to Al--(1% to 14%) Si filler metals result in larger fillets than conventional Al--Si alloys normally used in the NOCOLOK brazing process. This new filler metal can be clad to 2XXX, 3XXX, 6XXX, and 7XXX series alloys and brazed with a fluoride flux. The filler metal contains between 0.005% Ca to 0.3% Ca. The new filler metal could have up to 0.3% Mg and up to 0.3% Li. Additionally, the brazing process can optionally include an aqueous treatment with a fluoride salt to reduce the need for NOCOLOK fluxing.

Abstract: The invention relates to an oven for reflow soldering objects such as printed circuit boards. A temperature differential is established between the top and bottom surfaces of the board to allow gases liberated from solder paste within through-holes to escape, thereby preventing the formation of voids. The oven provides a flow of gas at a first temperature from an upper gas supplying means to the top side of the board. A flow of gas at a second temperature is directed at the bottom side of the board by a lower gas supplying means. According to one aspect of the invention, a portion of the gas supplied by the upper gas supplying means is captured by the lower gas supply means and is heated or cooled to the second temperature. According to another aspect of the invention, a number of pairs of independantly controllable upper and lower gas supplying means are arranged along a conveyor to provide a temperature profile to perform reflow soldering.

Abstract: Disclosed is a method and an apparatus for soldering a base material. A binary solder essentially consisting of tin and a metal which can form an eutectic alloy with tin and which is exclusive of lead is prepared. The content of other metallic components is 0.1% by weight or less and the content of oxygen is 100 ppm or less. The binary solder is melted in a non-oxidizing environment and dispensed to the base material in an atmosphere in which the oxygen content is 2,000 ppm or less, to solder the base material with the binary solder. The soldering apparatus comprises an oscillator for supplying oscillatory wave energy having frequency of 15 KHz to 1 MHz to the base material. The soldering apparatus can also be realized in the form of a soldering nozzle or a soldering iron.

Abstract: A solder head is adapted to direct the flow of solder from a solder fountain. The solder head includes a wall forming a passage through which solder can flow upwardly and having an edge portion over which solder can flow from the passage. The solder head also includes a shield connected to the wall. The shield and the wall at least partially define an overflow passage through which solder can flow downwardly. The shield is configured to prevent contact between solder and an electronic component adjacent the solder head. Corresponding soldering systems and soldering methods are also provided.

Abstract: A method and apparatus for placing and attaching solder balls to a substrate having conductive pads in a predetermined pattern is disclosed. The substrate is placed on a carrier plate. An alignment plate having holes corresponding to the predetermined pattern is mated to the carrier plate with its holes aligned with the predetermine pattern on the substrate. Solder balls are loaded into each hole of the alignment plate. The solder balls may be loaded with a vacuum plate which uses vacuum to pick up solder balls in the predetermined pattern and place them over the holes on the alignment plate. The vacuum is released for dropping the balls in the holes of the alignment plate. Alternatively a shutter plate having holes corresponding to the holes on the alignment plate is fitted on the alignment plate and afforded slidable movement between an offset position and an aligned position. A ball is loaded in each hole in the shutter plate when it is in its offset position.

Abstract: A gas flow controlling device including a housing having a gas inlet and a gas outlet and defining therewithin a gas flow passage diverging in the direction from the inlet to the outlet so that the cross-sectional area of the gas flow passage increases from the inlet to the outlet, and a plurality of spaced apart baffle plates provided in the gas flow passage to render the gas flow passage meandering. An apparatus for soldering an article, including a wave-soldering zone for contacting the article with a solder wave, and one or more above-mentioned gas flow controlling devices for establishing an inert gas atmosphere in the soldering zone.

Abstract: A method and implementing system is provided in which a gas, such as oxygen, is injected on to area of a circuit board to which an electronic component is being mounted. The injected gas causes a formation of a coating or surface alloy layer such as tin-oxide, on the solder joint. The coating causes the solder bead or joint to have a higher surface tension and a higher reflow temperature. In an exemplary double-sided double-pass assembly operation, circuit boards pass through a soldering oven on a first pass to attach components to a first side, and then the board is inverted and passed through the oven on a second pass while components are mounted on the opposite side of the board. During the second pass, a gas injection device is aimed at the component-to-board connection points on the inverted side of the board which were soldered on the first pass. The gas is injected at the point in the soldering reflow oven at which the temperature begins to exceed the solder reflow temperature.

Abstract: A big scale (500 cc) golf club head fabrication method includes the step of preparing molds for making a top cover panel, a bottom cover panel and a face panel, the step of preparing metal alloy plate materials and then cutting the metal alloy plate materials into the desired sizes and then using the molds thus obtained to forge the metal alloy plate materials into the desired top cover panel, bottom panel and face panel respectively, and the step of welding the obtained top cover panel, bottom panel and face panel in a vacuum tank to form a golf club head and then polishing the golf club head into a finished product.

Abstract: A heat exchanger assembly includes at least one tube having an internal surface and an external surface, a composition cladding having at least lithium and magnesium applied to either one of the internal surface and external surface of the tube, and at least one component disposed adjacent the composition cladding, whereby the tube and component are joined together during a controlled atmosphere brazing process.

Abstract: The invention relates to a novel ceramic substrate with at least one layer essentially of aluminum nitride which is provided on at least one surface side with an intermediate or auxiliary layer which contains aluminum oxide and which has a thickness in the range of 0.5-10 microns, and to a process for its production.

Abstract: A method for applying a plurality of solder globules to a substrate has a solder-globule fixing method, a plurality of glass fibers and a fibre holder. The solder-globule fixing method has provided therein a plurality of passages whose cross-sectional areas are smaller than the cross-sectional areas ofthe solder globules to be applied. The fibre holder is arranged relative to the solder-globule fixing device in such a way that between the fibre holder and the solder-globule fixing device a cavity is formed, which is adapted to be acted upon when submitted to pressure via a pressure-transmitting conduit. The fibre holder holds the glass fibres in alignment with the passages.

Abstract: A backpressure controlling device for welding purge gas comprising a vertically oriented cylindrical housing, a water outlet at the bottom of the housing and a water outlet in the wall of the housing and spaced up from the bottom of the housing, the water outlets defining a water volume space in the housing, a gas inlet tube and a concentric gas outlet tube surrounding the gas inlet tube, the gas inlet tube being adjustably positioned in the housing and having a length such that one end thereof extends below the water inlet and the other end thereof extending out of the housing for connection to a pipeline carrying purge gas, the gas outlet tube being secured to a spacer wall spaced from the upper end of the housing and extending to a point above the water outlet and communicating with the exterior of the housing through openings in the wall of the housing above the spacer wall, the housing being of a size such that the volume of the space above the water inlet is at least about one and one-half times as grea

Abstract: Screen printing and chip mounting are executed in a dry air atmosphere to prevent generation of solder balls due to absorption of moisture by a flux ingredient of paste solder. Screen printing of the solder on a board takes place in a space which has the board, a printing screen and a squeegee arranged therein and is formed therein with a dry air atmosphere having a pressure slightly higher than that of an atmosphere outside the space. Likewise, mounting of a chip on the board is carried out in a like space. Also, a reflow step is executed in a reflow oven kept at a dry air atmosphere.

Abstract: A method has been formed for direct solder "bumping" of wafers, chips and interconnection pads or traces on hard to solder surfaces such as aluminum and indium tin oxide. It has been discovered that conventional solders modified by the addition of a light reactive metal can be jetted in the form of microdroplets onto a hard to solder substrate and that the modified droplets will wet and bond to the surface of the hard to solder substrate. This makes it possible for the first time to create solder bumps on bare uncoated hard to solder substrates such as aluminum and indium tin oxide without the need for first applying a different surface which conventional solder will wet.

Abstract: An apparatus for emitting a laminar flow of inert gas at a location inside a reduced-width, high-aspect-ratio (ratio of depth to width) weld groove. The portion of the gas distribution apparatus extending into the groove has a thickness less than the width of the weld groove and distributes inert gas which displaces the ambient atmosphere overlying the molten pool area at the bottom of the weld groove. The gas distribution apparatus may take the form of a tube, a planar array of mutually parallel tubes joined at the sides, a monolithic block having an elongated cross section with a parallel array of channels drilled or machined therein, or a support frame covered by a gas-permeable skin. To achieve a laminar flow, a gas diffusing structure is incorporated in each gas distribution tube.

Abstract: A method for dry fluxing at least one metallic surface of an article comprising the steps of:a) passing at least one initial gas mixture comprising (1) at least one of an inert gas and a reducing gas and (2) an oxidizing gas mixture comprising water vapor into at least one apparatus for forming excited or unstable gas species, the initial gas mixture including 50 ppm to 6% water vapor;b) converting the at least one initial gas mixture to at least one primary gas mixture comprising excited or unstable gas species; andc) treating the surface to be fluxed, at a pressure close to atmospheric pressure, with a gaseous treatment atmosphere comprising excited or unstable gas species and substantially free of electrically charged species obtained from the primary gas mixture.

Abstract: An apparatus and method are available for detecting the presence of inert gas in an enclosure isolating one side of selected weld structures being joined during welding operation. The system and method include using an inert gas detector relying upon an electric filament positioned in a separate containment connected to the first containment in order to determined whether the required purity level of inert gas has been achieved in the weld enclosure.