Abstract: A low cost method for mechanically and electrically coupling a surface mounted capacitor to a semiconductor package. In one embodiment a metal coating is deposited over the electrodes of a capacitor. Concurrently, or at some other time, solder paste is applied to the electrical contact pads of a semiconductor package. The connection between the capacitor and package is made by positioning the metal coated regions of the capacitor over the electrical contact pads of the package and running the unit through a reflow furnace where the solder paste is wetted onto the metal coating of the capacitor and onto the electrical contact pads of the package.

Abstract: A heat exchanger assembly including at least one aluminum based tube having an internal surface and an external surface, an aluminum based lithium-magnesium composition cladding applied to either one of the internal surface and external surface of the tube, and at least one aluminum based component disposed adjacent the cladding, a modified aluminum brazing flux applied to a joint between the surface and one component. The modified aluminum brazing flux comprises cesium fluoride, lithium fluoride, or both. Preferably, the cladding further comprises cesium. To manufacture the heat exchanger assembly, the tube and component are joined together with flux applied in the area of the joint using a controlled atmosphere brazing (CAB) process.

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: Wave soldering or tinning machine comprising:a solder reservoir;a means that forms at least one solder wave having a laminar form and including a flat surface;a means for bringing a piece to be soldered or tinned into contact with the laminar wave; andmeans for injection of a gas in the vicinity of the wave comprising an injector located in a position adjacent to and downstream from the wave and provided with a wall facing the solder wave, wherein the wall has at least a first group of openings positioned so as to produce a first gas jet directed toward the flat surface of the solder wave.

Abstract: A method for wave soldering a circuit having two or more faces comprising the steps of:(i) passing at least one initial gas mixture comprising at least one of an inert gas, a reducing gas and an oxidizing gas into at least one apparatus for forming excited or unstable gas species;(ii) converting the at least one initial gas mixture into at least one primary gas mixture comprising excited or unstable gas species and substantially free of electrically charged species;(iii) treating each of the two or more faces of the circuit with the at least one primary gas mixture at a pressure close to atmospheric pressure; and(iv) contacting the two or more faces of the circuit with at least one wave of a liquid soldering alloy.

Abstract: An apparatus for providing inert gas to a desired location for a welding operation is provided. The apparatus includes a gas feed line and structure for mounting the feed line to extend in a first direction in a pipe. A gas locator tube communicates with the gas feed line to direct inert gas from the gas feed line in a second direction, different from the first direction, towards a pipe joint to be welded. The locator tube is capable of continually directing inert gas in the second direction as the pipe is rotated during a welding operation.

Abstract: A welding method for forming an oxide passivation film having corrosion resistance and an extremely small emission quantity of an outgas during welding at a weld portion and portions nearby, and a process apparatus requiring an ultrahigh-clean atmosphere. A back-shielding gas comprising an inert gas containing 1 ppb to 50 ppm of oxygen gas is caused to flow during a welding process, and an oxide passivation film comprising chromium oxide as a principal component is formed on the surface of the weld portion. In a process apparatus using welding for installing the apparatus, a back-shielding gas comprising an inert gas containing 1 ppb to 50 ppm of oxygen gas is caused to flow during a welding process and an oxide passivation film comprising chromium oxide as a principal component is formed on the surface of a weld portion.

Abstract: A method is available for wave-soldering component groups, especially printed circuit boards with shielding from the environment, in which lead-free or at least low-lead solders, especially tin solders, with a melting point of more than 210.degree. C., are used. Since in wave soldering the solder bath temperature must usually be set considerably higher than the melting point of the solder, problems with overheating the components are encountered with higher-melting lead-free or low-lead solders. This problem is solved in accordance with the invention by setting a solder bath temperature which is only a few degrees Celsius above the melting point of the solder material, and performing the wave-soldering by the action of a plasma of a process gas atmosphere at low pressure.

Abstract: A method for minimizing the clogging of a cooling zone heat exchanger of a reflow solder apparatus that includes the steps of: removing a gas/flux mixture from an exhaust zone (20) that is located adjacent a heated zone and/or a cooling zone; conducting the gas/flux mixture to and through a first filter chamber (22), conducting the filtered gas from the filter chamber (22) through a low pressure portion of a blower housing of a cooling zone (16), then subsequently to and through a high pressure portion (44) of the cooling zone that includes a collection tray (38), a mesh filter (48), a heat exchanger (46) and at least one perforated plate (50). The heat exchanger is thermostatically controlled at a preset tempering temperature that minimizes the collection of flux on its exterior surfaces while allowing a solder joint of an article to solidify.

Abstract: Method of welding a carbon steel and a austenitic stainless steel involves using high density energy beam like a laser beam or electron beam. Welding using high density energy beam is effective to obtain a high precision welding. For the purpose of obtaining both high precision and no cracks, and no deformation, the method of the invention controls the structure of a weld portion to be a mixed structure of an austenitic structure and not greater than 20 wt % of a ferritic structure.

Abstract: The invention has as an object thereof to provide a welding method which is capable of forming an oxide passivated film, which is corrosion resistant, non-catalytic, and has an extremely small amount of released gasses, chiefly on the welded portion or in the vicinity thereof during the welding process. During the welding process, a gas in which 800 ppm.about.2.5% of moisture is contained in an inert gas is caused to flow, and a passivated film having chromium oxide as a chief component thereof is formed on the surface of the welded portion. The welding method comprises a welding process and a passivation process; in the passivation process, a gas in which 1000 ppm.about.2.5% of moisture is contained in an inert gas is employed.

Abstract: Apparatus for soldering surface mounted devices to printed circuit boards utilizing a combination of forced convection and infrared radiation. Fans are disposed in each heating zone which force gas through a heating plate which heats the air, emits infrared radiation for heating of printed circuit boards, and establishes a flow pattern for the gas. Flows are controlled in each zone by selectively introducing unheated gas into each zone, and by selectively exhausting gas from each zone. The volume of gas introduced and exhausted from each zone can be controlled. Closures are provided in the return channels to the low pressure side of the fan for controlling the volume of gas recirculated from the conveyor. Flow is controlled such that cooler air is always introduced into the zones which have a lower temperature and is exhausted from zones which have higher temperatures.

Abstract: A reflow soldering system includes a reflow station with one or more soldering containers. Each container includes a base and a cover reciprocable to either open or close the container. When open, the container receives a printed circuit board/electrical circuit component assembly for reflow soldering, or permits the exit of such assembly after soldering. When closed, the container provides a fluid-tight seal between the chamber inside and the immediate outside environment. Container opening and closure are synchronized with an input conveyor providing assemblies to the container and an output conveyor removing the soldered assemblies, both of which are operated by a control system at a controlled rate of speed. When the container is closed, its internal environment is precisely controlled through heating elements in the container and several conduits for supplying air (heated if desired), for supplying an inert gas, and for drawing a vacuum.

Abstract: A gas injection apparatus and process to form a controlled atmosphere in a confined space, comprising at least one assembly of ducts installed in series and/or in parallel, of which at least a part (2, 12, 13) of a duct comprises gas injection apertures. The assembly is supplied by at least one gas supply main (9, 14, 15), each main being connected to the assembly at the level of a primary connection node (8, 16, 17), the dimensions of the assembly observing the following relationship:.SIGMA..omega..sub.i /.SIGMA..phi..sub.i .gtoreq.1, preferably .gtoreq.1.5;wherein .SIGMA..omega..sub.i represents the sum of internal sections of the gas supply mains feeding the assembly and .SIGMA..phi..sub.i represents the sum of the cross-sections of the gas injection apertures of the ducts assembly.

Abstract: An arrangement of applying flux in solid, liquid or gaseous form directly to the solder wave avoids prefluxing of printed circuit boards or other elements to be soldered or solder wetted. The process for wave soldering an element comprises the steps of forming a solder wave above a solder reservoir, applying a flux directly to the solder wave separately from a shield gas delivery means to blanket the solder wave, and conveying the element through at least a portion of the solder wave. The process is applicable to wave soldering under a shroud wherein a gas shield is supplied by diffusers under the shroud, the flux being applied by at least one gas applicator directly to the solder wave.

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: A method for soldering an electronic component capable of accomplishing satisfactory soldering of an electronic component using paste solder even in an oven constructed into a non-closed structure which causes flowing of an ambient atmosphere. Dehumidified air is introduced through a dehumidified air inlet section into the oven to keep a dehumidified atmosphere in the oven, to thereby prevented activity of flux contained in the paste flux from being deteriorated.

Abstract: The present invention relates to a wave soldering process wherein an inert gas atmosphere is injected inside the wave soldering machine, the inert gas atmosphere having a temperature which might be controlled. Particularly, the atmosphere can be heated at the same or different temperatures before injection, for example in the preheating zones, in the machine. The atmosphere can also be cooled (or injected at ambient temperature) e.g. in the cooling zone. Various atmospheres can be used (similar or different from one zone to another). Also, maintaining the atmosphere under forced laminer flow conditions improves the quality of the solder joints. The thermal efficiency of the heat transfer between the atmosphere and the printed circuit boards is thus greatly enhanced, which means less solder defects, higher components density and decrease of energy consumption and inert gas flow rate.

Abstract: A wave soldering process and apparatus in which a localized low oxygen-containing atmosphere is provided at the point of contact of the solder wave and the substrate to be soldered by bubbling an inert gas through the solder wave.

Abstract: A method of manufacturing golf club is to design the contour of a club head and a club shaft. Sheet metal forming for divided golf club head are formed by stretching the Titanium Alloy plate within the forming dies, then processed with stress relief. Assembly welding are processed in a vacuum chamber where inner-gas, argon, is filled therein to avoid any inpurity may occur on the product during manufacture. Temperatures for stress relief, solid solution and aging are controlled in various degree depending upon each different procedures in order to form a best quality in vacuum furnace where vacuum gauge is best under ten to the negative fourth power of TORR.

Abstract: A weld shield apparatus provides an atmosphere of inert gas within a conduit in an underbead region where an external weld joint is to be produced. The weld shield apparatus includes a diffuser structure having a convex exterior surface that is defined by a wall structure, the convex exterior surface is shaped to fit within the conduit and to be separated from an inner wall of the conduit by a clearance space. The diffuser wall structure is comprised of a porous material which enables gas communication between an inlet to the diffuser and the convex exterior surface. A seal is positioned immediately upstream from the diffuser structure and is positioned to engage the inner walls of the conduit so as to prevent the passage of gas in an upstream direction. A source of gas is coupled to the inlet to the diffuser structure and enables inert gas to pass through the porous material and to flow in a laminar manner, via the clearance space, past the underbead region and into the downstream region of the conduit.

Abstract: An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber.

Abstract: The present invention provides a reflow apparatus and method effective to make constant the internal gas flow direction in a heating section within a reflow furnace. A circulating gas path is formed in a heating unit which collects and causes the gas to flow from a sirocco fan, up the rear side of the heating unit and then down towards a circuit board moving along a transfer path at the front side of the heating unit. Moreover, a plurality of straightening plates are arranged above the transfer path of the heating unit so as to guide the hot gas, which is flowing forwardly downwardly toward the circuit board moving along the transfer path. A blow-down nozzle is provided and includes a plurality of plates aligned in rows in the transferring direction of the circuit boards. The plates have an inverse U-shaped cross section. The blow-down nozzle is arranged below the straightening plates to cause the vertical hot gas flows to flow uniformly over the whole surface of the circuit board.

Abstract: A solder composition is applied to the pins of an electronic component. The pins of the component are brought into contact with solder at a soldering station having a bath exposed to a controlled atmosphere of low oxygen content maintained in a hood enclosing at least the surface of the bath. The controlled atmosphere is comprised of at least one neutral gas and a gaseous silicon hydride whose content is between 50.times.10.sup.-6 and 2.times.10.sup.-3 of the volume of the controlled atmosphere. The controlled atmosphere is produced:a) by introducing into the hood the neutral gas to bring the residual oxygen content to less than 200 ppm, thenb) by introducing into the hood the neutral gas and the silicon hydride with a content greater than four times the residual oxygen content in the controlled atmosphere, at the end of step a).

Abstract: An essentially fluxless solder joining process comprises a solder coating to be applied to a surface under controlled pressure conditions enabling the volume and shape of the solder to be desirably controlled. Coatings produced by essentially fluxless processes enable joining processes to be carried out in an essentially fluxless manner with highly desirable processing flexibility.

Abstract: An apparatus and method for purging reactive gases from the vicinity of a molten weld during the welding process, having particular application to the welding of industrial process piping systems and pipelines, especially stainless steel and other alloy pipelines. A system is disclosed for boosting purging speed and efficiency by providing a multidirectional flow of purging gas adjacent to the interior walls of the pipe sections being joined. The rate of purge gas flow is automatically adjusted in response to changing gas pressures in the vicinity of the progressing weld.

Abstract: A circuit board is wave soldered as it is carried by a conveyor through a solder wave established in a solder reservoir. Disposed on both sides of the solder wave are gas plenums which discharge shield gas. The gas plenums include orifices for directing shield gas (i) at high velocity toward the solder wave to protect the solder wave with an atmosphere of shield gas, and/or (ii) upwardly toward an underside of the circuit board to strip entrained air therefrom. The solder wave is generated by a pump driven by a drive shaft that extends downwardly into the solder reservoir. An upper portion of the drive shaft is surrounded by a stationary hollow sleeve which projects into the solder reservoir to restrict the churning of the solder during rotation of the drive shaft. A shield gas is introduced into the sleeve to inert the solder being churned. An enclosure is positioned above the solder reservoir having an inlet and an outlet through which the circuit boards are conveyed.

Abstract: A circuit board is wave soldered as it is carried by a conveyor through a solder wave established in a solder reservoir. Disposed on both sides of the solder wave are gas plenums which discharge shield gas. Each gas plenum includes a top wall, a side wall, and a bottom wall. The side wall is spaced horizontally from the wave, and the bottom wall is submerged within the solder. The side and (optionally) top walls include orifices for directing shield gas (i) at high velocity toward the solder wave to protect the solder wave with an atmosphere of shield gas, and (ii) upwardly toward an underside of the circuit board to strip entrained air therefrom. Instead of being submerged within the solder, the bottom wall could be spaced above the solder and provided with orifices to emit shield gas downwardly between the plenum and solder reservoir to create an inert atmosphere above the solder.

Abstract: An apparatus for providing a gas shield includes two radially adjustable walls disposed in spaced relation to each other along a substantially common central axis, each wall including a plurality of radially oriented wall segments defining a substantially flat, round wall having a circumference; a wedge structure for radially displacing the plurality of radially oriented wall segments between an expanded position wherein the circumference of each wall is expanded and a withdrawn position wherein the circumference of each wall is withdrawn; and a conduit for introducing a shield gas into a space defined between the two radially adjustable walls.

Abstract: An apparatus and process prepares surfaces on components, boards and the like for assembly and solder joining. Oxides and other coatings can be removed from surfaces to be soldered without having to solder coat surfaces prior to joining. A polymer and an activator combination is applied to the surfaces, the polymer being thermally de-polymerizable and the combination removing oxides from the surfaces. The surfaces are heated after application of the polymer and activator to de-polymerize the polymer. Solder is then applied to solder join the surfaces.

Abstract: A method for bonding a solder wire is provided wherein a lower ball end of a material solder wire is first bonded to a first bonding portion of a workpiece. Then, the material solder wire is thermally cut to provide a solder wire segment held bonded to the first bonding portion and having an upper ball end. Finally, the upper ball end is bonded to a second bonding portion of the workpiece. All of the wire bonding process steps are performed in an oxygen-free atmosphere to prevent oxidation of the solder wire.

Abstract: An open faced trailing weld shield for constraining an inert gas to a welding puddle area and a solidifying weld area of a joint of abutting metal members that are reactive in the atmosphere at an elevated temperature while permitting viewing of such weld areas as a welding torch to which the shield is attached traverses the joint in a welding operation and permitting viewing of such weld areas to monitor the weld procedure and changing weld parameters as may be required. The shield includes a U-shaped tube member having closed end leg portions and a plurality of spaced downwardly opening aperture. A frame member closely surrounds the U-shaped tube member and is provided with a flared downwardly extending opening so that an inert gas that is introduced into the tube member flows downwardly to shield the weld puddle and the solidifying weld area until it has cooled sufficiently to be nonreactive with the atmosphere.

Abstract: An apparatus and method for purging reactive gases from the vicinity of a molten weld during the welding process, having particular application to the welding of industrial process piping systems and pipelines, especially stainless steel and other alloy pipelines. A system is disclosed for boosting purging speed and efficiency by providing a multidirectional flow of purging gas adjacent to the interior walls of the pipe sections being joined. The rate of purge gas flow is automatically adjusted in response to changing gas pressures in the vicinity of the progressing weld.

Abstract: A process for wave soldering or reflow soldering comprises contacting substrates with a supply of molten solder containing from about 0.0001 to about 0.1% by weight of phosphorous in an atmosphere of diluent gas containing up to about 0.1% by volume oxygen. A reduced incidence of bridging and other soldering defects occurs.

Abstract: A novel method and apparatus improves the physical and electrical soldering bond between two electronic components by fluctuating the pressure of a non-oxidizing gas in a chamber which houses the two electronic components throughout a period when the solder has been made molten. This results in the solder effectively filling all crevices and grooves present on the surfaces being soldered. The method is particularly advantageous for soldering a ridge wave-guide laser diode P-side down to a heat sink to improve power capability, longevity and performance of the laser diode.

Abstract: Solder interconnection arrays for joining a plurality of metallic surfaces located on a first surface to a plurality of metallic surfaces located on a second surface are provided which reduce the amount of stress on particular areas of the interconnect array caused by shear forces between the surfaces.

Abstract: A micro soldering apparatus and method comprising a system (10) for attaching an electronic component (12) to a substrate (14). The system (10) comprises a soldering tool (16) including a dispensing orifice assembly (18) for pulsatingly dispensing a controlled quantity of molten solder (19) to a component (12) and substrate (14) so that the component is joined to the substrate (14) mechanically and electrically upon solidification of the molten solder (19). There is no physical contact between the dispensing orifice assembly (18) and joint. The system (10) also includes a controller for the soldering tool (16). The controller functions in response to process control parameters so that the controlled quantity of molten solder (19) is dispensed through a non-oxidizing atmosphere by a pressure pulse applied to the molten solder.

Abstract: An apparatus and method of reflow soldering electronic components, preferably to printed circuit boards, in an inert atmosphere to reduce solder defects and the need for flux or cleaning wherein the inert atmosphere is provided from a source of inert gas through several distribution lines which parallel the conveyor belt of a reflow solder furnace and supply each end of porous sintered metal diffuser tubes situated above the conveyor belt, as well as gas knives situated in baffle compartments at the inlet and outlet of the reflow solder furnace to strip barrier layers of oxygen atmosphere from the electronic components and preclude ingress of oxygen atmosphere into the reflow solder furnace.

Abstract: A cover plate extends over at least part of a solder reservoir and has a slot for a solder wave to extend up above the cover plate. Shield gas is supplied under the cover plate to blanket the solder wave and prevent air from contacting the solder wave and circuit boards passing through the solder wave. Circuit boards are generally supported by conveyor fingers at side edges and the fingers pass through the solder wave. End shrouds are provided at both ends of the solder wave to prevent the entry of air through the conveyor fingers and to ensure that the side edges of the circuit board are uniformly blanketed by shield gas directed to the side edges passing up through the slot in the cover plate. The under surface, front edge, back edge and side edges of a circuit board are therefore uniformly blanketed by shield gas as the board passes through a solder wave.

Abstract: An improved method and apparatus for shielding inert gas from seeping out of metal pipes in a welding application wherein a high-temperature resistant purge strap is placed around the weld gap and the pipe ends. Advantageously, the purge strap is equipped with a window to allow the welder access to the pipe ends. Dams may be inserted into each pipe near the end to be welded, the purge strap placed about the pipes covering the end of each, and inert gas pumped into the pipes, displacing the air within the pipes. A weld bead is laid into the gap and the purge strap is shifted around the circumference of the pipes to allow completion of the weld. The purge strap device is also disclosed.

Abstract: In a method of soldering for use in fabricating electronic circuit device, after an oxide layer and/or contaminated layer on a surface of a soldering material and members to be soldered thereby is removed by sputter-cleaning with atom or ion, the members are aligned in an oxidizing atmosphere within a predetermined time period and, then, the soldering material is heated in non-oxidizing atmosphere to performe soldering. An apparatus for performing the above method comprises a sputter cleaning device, an alignment device operable in atmospheric condition and a heating and soldering device in the form of a belt furnace operable in non-oxidizing or reducing environment. Instead of the sputter cleaning device, a mechanical polishing or cutting device can be used to cleaning a surface of solder or a member to be bonded or a solder ball plated with gold may be used.

Abstract: Disclosed is a solder tool for reworking a pin-in-hole printed circuit board. The solder tool has means for providing a gas blanket. Also disclosed is a method of reworking a pin-in-hole printed circuit board using the solder tool.

Abstract: A technique is provided for manually performing a soldering operation on an article with a low-solids flux-containing solder to bond an object to the article with a reduced amount of flux residues. The technique is practiced by first manually applying heat to the article and to the object which is in contact therewith, such as by contacting the article and/or object with a heated tip of a soldering pencil, iron or gun. Once the object and article have been heated, a low-solids flux-containing solder is then applied so as to be reflowed upon contact with the heated article and the object in order to bond them together when the solder solidifies. Simultaneously, heated air (i,e., air heated above the ambient temperature) is directed at the article and the object towards the region where the solder is being applied to maintain any flux vapors, which were created upon heating of the solder, in their vaporous state.

Abstract: Aluminum or aluminum alloys are brazed in the presence of a non-corrosive flux using a low-cost, substantially dry nitrogen atmosphere produced by a non-cryogenic air separation technique such as a pressure swing adsorption (PSA) or a selective permeation (membrane). The use of a substantially dry, non-cryogenically produced nitrogen atmosphere brazed aluminum or aluminum alloy components with consistent good brazed joint quality and appearance while utilizing low loading of the flux.

Abstract: A soldering apparatus includes a conveyor adapted to carry assembled circuit boards through a soldering chamber. A wave of solder is created in the chamber. The chamber has a curtain at its entrance and a curtain at its exit. Gas distributors are located within the chamber and are able to introduce nitrogen into the chamber in order to create a non-oxidizing atmosphere in the vicinity of the wave. In operation, the wave of solder wets connecting points between the components and the board to form permanent joints on solidification of the solder. The bottom edge of the curtain is of a shape complementary to the front elevation of the assembled circuit boards to be soldered and is arranged such that the circuit boards just pass thereunder without making contact with it.

Abstract: An inert gas nitrogen mixture is used as a shielding gas to prevent weld hot cracking in superalloys containing zirconium and/or boron. The gas mixture preferably contains argon and about 2 to 8% by volume nitrogen. Test data show excellent results are obtained when gas tungsten arc welding HAYNES 214 alloy which normally contains boron and zirconium and a minimal content of titanium.

Abstract: A process for welding stainless steel tubing in the presence of an inert gas comprising a silicon base gas, in particular silane SiH.sub.4. During the welding operation, a suitable quantity of silicon is deposited by chemical vapor deposition at the weld joint to significantly improve the corrosion resistance of the weld.

Abstract: Wave soldering method and apparatus for fluxing a substrate in a low oxygen containing atmosphere, preheating the fluxed substrate at least partially in a non-low oxygen containing atmosphere, and soldering the preheated substrate in a low oxygen containing atmosphere.

Abstract: A method of soldering for surface mounting of a printed circuit board, which comprises performing reflow soldering with a rosin-based cream solder in a special atmospheric gas comprising an inert gas such as N.sub.2, Ar or He and containing about 10,000 ppm or less of oxygen and 0.5-3.0% of moisture is disclosed.

Abstract: The invention relates to a wave soldering device in which solder is pumped up from a solder bath and through a tower and issues therefrom in the form of a wave which engages the underside of a circuit board, flows over a front and/or rear weir of the tower and returns to the solder bath. A conveyor transports circuit boards across the top of the tower and the solder wave. A confining structure is situated adjacent the wave and protrudes into the solder bath. A gas which substantially excludes oxygen is injected from a nozzle and follows a circuitous route bordered by solder in the bath, solder flowing over the rear weir, and walls of the confining structure. The gas exiting from an outflow opening of the confining structure is directed across the solder flowing over the rear weir and onto the downstream line of contact of the solder wave and the board as it leaves the solder wave.